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    • 1  Subdivision of tectonic units in China
    PAN Gui-tang ,  XIAO Qing-hui ,  LU Song-nian ,  DEN Jin-fu ,  FENG Yi-min ,  ZHANG Ke-xin ,  ZHANG Zhi-yong ,  WANG Fang-guo ,  XING Guang-fu ,  HAO Guo-Jie ,  FENG Yan-fang
    2009, 36(1):1-28.
    [Abstract](27153) [HTML](0) [PDF 16.00 M](17002) [Cited by](124)
    Abstract:
    Abstract： Researches on tectonic formation, evolution and subdivision in China have had a history of more than 100 years. There are several kinds of opinions concerning the tectonic subdivision of China, which are based on different sorts of epistemology and methodology regarding the formation and evolution of the continental crust. Tectonic subdivision blueprints guided by “three mainstream tectonic views” include Mr. Huang Jiqing's polycyclic tectonics, Mr. Wang Hongzhen's historical tectonics and Mr. Li Chunyu's plate tectonics. The ideas of these researchers have been playing a guiding role in this field and hence have had extensive and profound influence in China. Nowadays tectonic subdivision seems to be the key to the research on micro-structures of plates in that it is not only a theoretical problem in the study of plate tectonics but also a practical problem which must be solved immediately so as to help perform studies in such aspects as regional geology, metallogenic prognosis and mineral resources evaluation. In this paper, the tectonic subdivision is based on records of stratigraphic division and correlation, sedimentary formation, volcanics formation, intrusive magmatism, metamorphism and deformation, and consistent with the classic division theory of “three mainstream tectonic views” in China. Guided by theories of plate tectonics and earth dynamics, based on the requirements of metallogenic regularity and mineral energy resource prognosis, and following the main line of spatial-temporal structure analysis of tectonic facies environment of different-sized stable ancient continent block domains and different episodic orogenic systems, the authors have divided the tectonic environment of China into continent block domains and orogenic systems, which include nine first-order tectonic units and fifty-six corresponding second-order tectonic units. As there are a number of major tectonic problems in China that remain to be solved in future, a prolonged painstaking efforts are still needed for more accurate subdivision.
    2  Orogenic-type deposits and their metallogenic model and exploration potential
    CHEN Yan-Jing , 
    2006, 33(6):1181-1196.
    [Abstract](13866) [HTML](0) [PDF 1.64 M](13237) [Cited by](101)
    Abstract:
    Abstract：Identification of a new type mineralization often leads to discovery of a great number of ore deposits and ore provinces. Predicting and identifying new type mineralizations is an important aim of ore deposit study. To date the majority of orogenic-type gold deposits has been well shown by worldwide studies. However, the other commodities of orogenic-type are rarely discussed. This paper addresses the concept of orogenic-type deposits which formed by fluid systems mainly sourced from metamorphic devolatilization. The paper also develops genetic models for orogenic deposits at various scales, including deposit-, orefield/terrain- and province/orogen-scales. The genetic models are linked to a three-stage tectonic evolution of convergent orogens. According to these models, the transition from compression to extension of thickened accretionary or/and collisional orogens is conducive to mineralizations; and the syn-orogenic ore-systems must be characteristically lagged behind compressional orogenesis. As case studies, orogenic-type silver, lead-zinc, molybdenum and copper deposits are reported in the paper. This implies that China has great potential for orogenic-type deposits. The logics and validity of the metallogenic models are evidenced by introduction of several successful ore deposit prediction.
    3  Metallogeneses in the collisional orogen of the Qinghai-Tibet Plateau：Tectonic setting, tempo-spatial distribution and ore deposit types
    HOU Zeng-qian ,  MO Xuan-xue ,  YANG Zhi-ming ,  WANG An-jian ,  PAN Gui-tang ,  QU Xiao-ming ,  NIE Feng-jun
    2006, 33(2):340-351. DOI: 10.12029/gc20060213
    [Abstract](8690) [HTML](0) [PDF 1.42 M](7761) [Cited by](90)
    Abstract:
    Abstract：Metallogeny of continents is an important research frontier in the contemporaneous metallogenic study, and its theoretical framework is conceived and established by gaining a deep knowledge and understanding of metallogeny in the continental collisional orogen. For a long time, geologists cannot reach a common view on the stages of collisional metallogeny and dynamic process in various stages because of a poor understanding of metallogeny in typical collisional orogens and coupling and genetic relations between the collisional orogenic process and crust/mantle interaction on the one hand and metallogenesis on the other. The Qinghai-Tibet Plateau orogen, which is characterized by the occurrence of large-scale, intense and young mineralization as well as many types of large and well-preserved deposit, is regarded as an ideal natural laboratory for studying ore-forming processes on continents and solving the above-mentioned problems. Through three years of systematical research on the metallogeny in the collisional orogen of the plateau, our project team has established a temporal-spatial framework of major mineralization events on the plateau, proposed a model of geodynamics and tectonic constraints on the ore-forming processes and put forward a set of complete theories on metallogeny in the collisional orogen. Three ore-forming processes and twelve deposit types are proposed in the new theories；they are：(1) metallogeny in the period of syn-collisional orogeny (65–41 Ma, four deposit types)；(2) metallogeny in the period of late-collisional transformation (40–26 Ma, four deposit types)；and (3) metallogeny in the period of post-collisional crustal extension (25–0 Ma, four deposit types). The corresponding key factors controlling the ore-forming processes are：(1) collisional orogenic setting, crustal magmatic activity and large-scale shear deformation;(2) intercontinental plate transformation setting, mantle-derived magmatic activity and large-scale strike-slip motion-nappe thrusting-shear deformation；and (3) post-collisional crustal extension setting, crust/mantle magmatic activity and hydrothermal convection system.
    4  Zircon SHRIMP dating of the Cailing granite on the eastern margin of the Qitianling granite, Hunan, South China, and its significance
    FU Jian-ming ,  MA Chang-qian ,  XIE Cai-fu ,  ZHANG Ye-ming ,  PENG Song-bai
    2004, 31(1):96-100. DOI: 10.12029/gc20040115
    [Abstract](6002) [HTML](0) [PDF 866.64 K](6978) [Cited by](73)
    Abstract:
    Abstract：The Cailing granite on the eastern margin of the Qitianling granite was precisely dated at 160±2 Ma using zircon SHRIMP, which suggests that the Cailing granite was intruded in the early Yanshanian, rather than in the Indosinian as is considered previously. A few inherited cores record Mesoproterozoic age information, which indicates that Precambrian rocks might be one of the important components in the granitic magma melting source region in the study area.
    5  Important role of the formation of gas accumulations in the late stage in the formation of large gas fields
    DAI Jin-xing ,  WEI Yan-zao ,  ZHAO Jing-zhou , 
    2003, 30(1):10-19. DOI: 10.12029/gc20030102
    [Abstract](4455) [HTML](0) [PDF 1.01 M](5693) [Cited by](67)
    Abstract:
    Abstract: By the end of 2001, 21 large gas fields had been discovered in China, and their cumulative explored reserves of gas in place reached 17953×108 m3, taking up 59.80% of China＇s total gas reserves. Gas molecules are small, hard to be adsorbed and ready to diffuse. Large early-formed gas fields will lose their quantity and become small or medium-sized ones or even be depleted completely owing to long-continued gas diffusion, if no gas source replenishes the supply. Therefore, the formation of gas accumulations in the late stage is one of the fundamental conditions for the formation of large gas fields. Basins in China are polycyclic in nature. The tectonic cycle of succeeding basin usually reduces or damages the reserves and preservation conditions of gas accumulations in the preceding basins. So, the formation of gas accumulations in the late stage can avoid this defect and is favorable for the formation of large gas fields. The period of peak gas generation of large gas fields resulting from late-stage accumulation is synchronous or nearly synchronous with the period of accumulation, and their source and reservoir rocks are younger. Sometimes, the peak generation period is earlier than the period of accumulation and their source and reservoir rocks are older.
    6  Characteristics and geological significance of adakitic rocks in copper-bearing porphyry in Baogutu, western Junggar
    ZHANG Lian-chang ,  WAN Bo ,  JIAO Xue-jun，ZHANG Rui
    2006, 33(3):626-631. DOI: 10.12029/gc20060320
    [Abstract](7501) [HTML](0) [PDF 675.34 K](6593) [Cited by](63)
    Abstract:
    Abstract：In the Darbute-Baogutu area, western Junggar, there outcrop two types of intermediate-acid intrusive rocks：late Hercynian (<270 Ma) granite batholiths and late-mid Hercynian (330–320 Ma) intermediate-acid small porphyry bodies. The Baogutu porphyry copper deposit is hosted in the latter. The Major element and trace element analysis of the rocks indicate that the Baogutu copper-bearing small porphyry in the mine meets the conditions of adakitic rocks, i.e.：SiO2>56%, Al2O3>15%, MgO<3%, Y<18×10-6, Yb<1.9×10-6 and Sr>400×10-6 and pronounced HREE depletion. Its Nd and Sr isotopic compositions are close to that of MORB. However, the composition of some samples, which is characterized by relatively high MgO contents (>3%) and a relatively low LREE abundance), is deviated from the compositional range of adakitic rocks. According to the geochemical composition of porphyries, combined with the regional geological characteristics, the authors think that the Baogutu copper-bearing porphyry originated in an island-arc environment related to intraoceanic subduction but that the initial melt of the oceanic crustal slab was subjected to inhomogeneous contamination with mantle peridotite during its rise.
    7  Ore deposits as a guide to the tectonic evolution in the East Tianshan Mountains, NW China
    WANG Jing-bin ,  WANG Yu-wang ,  HE Zhi-jun
    2006, 33(3):461-469. DOI: 10.12029/gc20060302
    [Abstract](3258) [HTML](0) [PDF 1.16 M](5252) [Cited by](61)
    Abstract:
    Abstract： Ore deposits are an important indicator for the tectonic evolution. The characteristics and space-time distribution pattern of ore deposits provide new constraints for reconstructing the tectonic evolution in the East Tianshan Mountains. Study indicates that the Paleozoic East Tianshan orogenic belt, sandwiched in between the Tuha block and Central Tianshan block, may be divided into three tectonic-strata (magmatic)-metallogenic belts in terms of spatial distribution, i.e.： the southern Tuha basin marginal copper metallogenic belt (north belt), Kanggur gold metallogenic belt (central belt) and Aqishan-Yamansu Fe (-Cu)-Ag- polymetallic metallogenic belt (south belt). The temporal evolution of the East Tianshan orogenic belt is distinctly characterized by three stages. (1) The southern margin of the Tuha Basin was an Ordovician-Devonian active continental margin, where there occurred a paleocontinental-margin metallogenic system including VMS Cu-Zn deposits and porphyry copper deposits. In the terminal Late Devonian-initial Early Carboniferous, the paleo-oceanic crust was subducted northward, closing the ocean, and the Central Tianshan block accreted and was amalgamated to the southern margin of the Tuha block (which belongs to the Kazakhstan-Junggar plate). (2) In the Early Carboniferous (Visean), the East Tianshan again underwent extension along the Kanggur suture, forming Carboniferous aulacogen volcanic-sedimentary rocks and a corresponding stratabound metallogenic system (including VMS type Cu-Zn deposits and volcanic-hosted Fe (-Cu) deposits and native copper deposits), and skarn type Ag polymetallic deposits formed during the closing stage of the aulacogen. (3) In the Early Permian, a Cu-Ni sulfide metallogenic system related to mantle-derived magma underplating and spanning tectonic units and gold deposits related to shearing formed in this area. Based on the above discussion, new suggestions about mineral prospecting in the East Tianshan area are put forward in this paper.
    8  Age of the "Dahalajunshan" Formation in Xinjiang and its disintegration
    ZHU ZHOU Jing ,  Yongfeng ,  SONG Biao ,  ZHANG Lifei ,  GUO Xuan
    2006, 33(3):487-497. DOI: 10.12029/gc20060305
    [Abstract](4039) [HTML](0) [PDF 1.18 M](5315) [Cited by](60)
    Abstract:
    Abstract:Based on previous research and zircon SHRIMP data, the authors suggest that the "Dahalajunshan Formation" should be disintegrated into several different formations. They establish a new formation named the "Laerdun Daban Formation" for the volcanic rocks exposed in the Laerdun Daban in the eastern segment of the West Tianshan, which are thought to be the product of La Te Carboniferous volcanism. The "Dahalajunshan Formation" will still be used for the Early Carboniferous rocks south of Xinyuan City. Volcanicsedimentary The volcanic rocks of the "Dahalajunshan Formation" exposed extensively in the western segment of the West Tianshan Mountains are relatively complex. Thus the name "Dahalajunshan Formation" will continue to be temporari Ly used for the Early Carboniferous rocks in the Dahalajunshan area Volcanicsedimentary south of Tekes where the original naming section of the "Dahalajunshan Formation" is distributed. The volcanic rocks distributed extensively in the northern part (Northern Gold Mine Area ZhaosuTekesiGongliuAxi) formed in the Late Devonian rather than in the Early Carboniferous as PR Evious believed. Therefore the authors suggest that a new name -- the Tekes Daban -- "Formation" be used for this suite of Late Devonian Volcanicsedimentary rocks.
    9  Basic characteristics of the Karamay ophiolitic mélange, Xinjiang, and its zircon SHRIMP dating
    XU Xin ,  HE Guo-qi ,  LI Hua-qin ,  DING Tian-fu ,  LIU Xinｇ-yi ,  MEI Shao-wu
    2006, 33(3):470-476. DOI: 10.12029/gc20060303
    [Abstract](3194) [HTML](0) [PDF 801.87 K](4442) [Cited by](60)
    Abstract:
    Abstract：The newly discovered Karamay ophiolitic mélange distributed along the NW edge of the Junggar basin has a complete sequence of ophiolite and accretionary complex. From the basin edge toward the mountains, ultramafic rocks, mafic, pillow lavas and abyssal radiolarian cherts generally show a zonal distribution. The ultramafic rocks are unconformably overlain by volcanic molasse. The ages given by zircon SHRIMP dating of altered gabbro samples taken from the Baijiantan segment of the Karamay ophiolite mélange cluster at 414.4±8.6 and 332±14 Ma. This discovery provides important evidence for studying the ages of formation and elimination of the Central Asian ocean basin and also an important clue ｔｏ the determination of the nature of the basement of the Junggar basin.
    10  A tectonic model for porphyry copper-molybdenum-gold metallogenic belts on the eastern margin of the Qinghai-Tibet Plateau
    HOU Zeng-qian ,  ZHONG Da-lai ,  DENG Wan-ming
    2004, 31(1):1-14. DOI: 10.12029/gc20040101
    [Abstract](4497) [HTML](0) [PDF 1.31 M](6263) [Cited by](60)
    Abstract:
    Abstract：Accompanied by hypabyssal emplacement of high-potassic alkali-rich porphyries, “paired” Cenozoic intracontinental porphyry copper-molybdenum-gold belts, controlled by large strike-slip faults, occurred on the eastern margin of the Qinghai-Tibet Plateau formed by India-Asia collision. Of the two metallogenic belts, the west belt is the Jomda-Markam-Xiangyun copper-molybdenum belt and the east belt is the Zhongdian-Yanyuan-Yao＇an porphyry copper-gold-lead-silver belt. The rock types of ore-bearing porphyry include granite porphyry, monzogranite porphyry and monzonite porphyry with small amount of syenite porphyry. They are distinguished from barren porphyry by their higher SiO2 (>63%) and lower Y (<20×10-6) and their adakitic magma affinity. Alkali-rich porphyry is relatively enriched in large-ion lithophile elements (K, Rb and Ba) and depleted in high-field strength elements (Nb, Ta, Ti and P) with a wider range of Nb/Y ratios and shows strong REE fractionation but no pronounced negative Eu anomaly—all these suggest that the magma source region underwent metasomatism and concentration of ancient subducted oceanic slab fluids and was injected by small streams of melts from the asthenosphere. Ore-bearing adakite-like porphyry might originate from the basaltic lower crust. The latter underwent high-pressure (>40 km) low amphibolite-eclogite facies metamorphism and slab fluid metasomatism and occurs as lower-crustal amphibolite xenoliths in alkali-rich porphyry. Barren syenite porphyry might originate from the hydrated phologopite peridotite-enriched mantle. Its trace element and Su-Nd-Pb isotope systematics indicate that their source region was subjected to much stronger slab fluid metasomatism and mixing of asthenospheric material. Available data of deep geophysical exploration suggest that since 50 Ma BP the Yangtze continental slab was subducted westwards and collided with the subducted Indian continental slab, thus inducing upwelling, thermal erosion and underplating of asthenospheric melts and giving rise to partial melting of the crust-mantle transition zone. The magma of adakite-like porphyry is characterized by the presence of relatively rich water, rich sulfur and higher oxygen fugacity (fo2). It was an important metal and sulfur carrier and formed porphyry copper-gold-lead-silver deposits in a shallow-level closed system.
    11  Characteristics and ore prospects of tin deposits in the Qitianling area, Hunan
    WEI Shao-liu ,  ZENG Qin-wang ,  XU Yi-ming ,  LAN Xiao-ming ,  KANG Wei-qing ,  Liao Xing-yu
    2002(1):67-75. DOI: 10.12029/gc20020111
    [Abstract](6340) [HTML](0) [PDF 416.19 K](7303) [Cited by](59)
    Abstract:
    Abstract: The breakthrough in tin exploration in the Qitianling area, Hunan Province, is a major achievement scored in the large? Juan scale The Land and Resources Survey in the last two years. Tin deposits in the area occur as veins in the southern part of the Qitianling composite granite body and its contact zone. The dominant tin deposit types include the greisenized granite type, altered porphyritic granite type and altered structural belt type, all of which are characterized by wide and thick orebodies, strong alteration, high tin grade and high performance of ores. At present, tin resources are estimated at about 600000 tons, and, in addition, the northern part of Qitianling with similar metallogenic conditions and other districts in the same tectono? Juan magmatic belt are also promising. More fruitful results will be achieved when the large? Juan scale The Land and Resources Survey is carried out further.
    12  Geochemical blocks-Development of concept and methodology
    XIE Xue-jing ,  LIU Da-wen ,  Xiang Yun-chuan ,  YAN Guang-sheng
    2002(3):225-233. DOI: 10.12029/gc20020301
    [Abstract](8550) [HTML](0) [PDF 1.08 M](6758) [Cited by](55)
    Abstract:
    Abstract: Geochemical distribution data (several tens of millions) of 39 elements were obtained in China's national geochemical mapping program carried out for 24 years over more than 6 million km2 of China's territory. By examining the flood of data, the authors have found much broader geochemical patterns other than dispersion halos and dispersion trains which have been the main subjects of study during the 60 years' development of exploration geochemistry. Such broader geochemical patterns are geochemical anomalies, geochemical provinces, geochemical megaprovinces and geochemical domains. They are surface expressions of the internal structural features of large blocks of rock with higher metal contents. Those large "geochemical blocks" are the net results of the Earth's original heterogeneity and the distribution and redistribution of metals from the initiation and evolution of the Earth up to the present days. The authors got a new idea that the large can provide large metal endowments necessary for the formation of large to superlarge geochemical blocks ore deposits. To explore the internal structure of the geochemical block of a certain element may reveal the trajectory of gradual concentration and formation of ore deposits of that element in the geochemical block. The new geochemical block concept is changing the mineral exploration strategy and methodology in China, providing a powerful tool for global mineral potential assessment and inspiring new ideas for exploration geochemistry, ore-genesis and metallogeny.
    13  Comparative study of the geology and mineral resources in Xinjiang, China, and its adjacent regions
    HE Guo-qi ,  ZHU Yong-feng
    2006, 33(3):451-460. DOI: 10.12029/gc20060301
    [Abstract](2749) [HTML](0) [PDF 1.23 M](4147) [Cited by](55)
    Abstract:
    Abstract：This paper primarily summarizes the basic characteristics of the major metallogenic belts in Central Asia and discusses the possible extensions of the major metallogenic belts from the adjacent regions of Xinjiang to Xinjiang. With the constantly changing knowledge of the division of metallogenic belts and types and characteristics of metallogenic formations in adjacent regions of Xinjiang, the authors emphasize that in comparing the geology and mineral resources in Xinjiang with those in its adjacent regions it is necessary to gain knowledge of their research histories and seek to make such comparison based on ascertaining basic ore-controlling elements. In addition, in Central Asia mineralization related to Early Paleozoic continental crustal accretion is quite important, while Late Paleozoic large-scale mineralization is more markedly manifested by inheritance and reworking of pre-existing ore-forming material and superimposition of new ore-forming material, thus forming compounding of multi-stage mineralizations. All these belong to the characteristics of the Central Asian metallogenic megaprovince and must be fully considered in the comparative study. Analysis and comparative study in the paper suggest the following six metallogenic environments as the major factors controlling the formation of large and superlarge deposits in the Central Asian metallogenic megaprovince： 1) numerous Precambrian blocks in Phanerozoic orogenic belts, in which important primary uranium deposits and rare metal deposits are formed; 2) Early Paleozoic continental-margin accretionary wedge and late Caledonian eastern Kokchetav and northern Junggar (beyond the territory of China), where there occur important gold and copper polymetallic deposits; 3) the circum-Balkhash Lake region surrounded by Caledonia and pre-Caledonian continental crust, where ore-forming processes show several peaks and superimposition on each other or certain regular migration; 4) an important Au-Cu-Mo-W metallogenic belt in the southern part of the Central Tianshan (beyond the territory of China), which shows distinct linear features and is related to a huge hydrothermal system that was active for ~70 Ma; 5) the post-collisional intracontinental environment in South Kazakhstan and areas south of it, where most U deposits in Meso-Cenozoic basins and Late Paleozoic superlarge sandstone-type copper deposits were formed and their ore-forming materials probably have deep sources; and 6) sites of intersection between the so-called large-scale “transverse structures” and metallogenic belts, where most important deposits in Central Asia occur.
    14  Lithospheric structure and large-scale metallogenic process in Southeast China continental area
    YANG Ming-gui ,  HUANG Shui-bao ,  LOU Fa-sheng ,  TANG Wei-xin ,  MAO Su-bin
    2009, 36(3):528-543.
    [Abstract](4137) [HTML](0) [PDF 3.32 M](6410) [Cited by](54)
    Abstract:
    Abstract：Based on regional geology, mineral geology and geophysics in combination with researches on the lithosphere and the earth's interior, the authors studied the variation of the crustal thickness of such geological bodies as block, orogeny, paleoplate suture zone (conjunction zone), uplift zone, depression belt and fault basin as well as that of the mass structure, Moho form and the lithospheric mantle in Southeast China continental area, carried out structural regionalism, discussed in detail the Yanshanian intracontinental orogenesis and the Himalayan continental extension as well as the process leading to the adjustment of lithospheric mass structure, and formulated an adjustment model for uplift and depression structural differentiation and crust-mantle mass structure. In addition, the thinning process of the crust at depth was investigated, and the dynamic mechanism of Yanshanian intracontinental orogeny as well as the large-scale ore-forming process in relation to the lithospheric mass structure was analyzed.
    15  Two tectonic systems in the Cenozoic Bohai Bay basin and their genetic interpretation
    QI Jia-fu
    2004, 31(1):15-22. DOI: 10.12029/gc20040102
    [Abstract](3339) [HTML](0) [PDF 796.16 K](5438) [Cited by](53)
    Abstract:
    Abstract：The Paleogene Bohai Bay basin may be divided into three rift zones and one rift area, which correspond to the updoming zone of the upper mantle. The tectonic deformation in the basin may be classified into two relatively independent and interconnected Cenozoic tectonic systems: the extensional tectonic system and strike-slip tectonic system. The extensional tectonic system is a linked fault system formed by extensional faults of different scales and transform faults perpendicular or oblique to the extensional faults. In the basin they are dispersed and penetrate into the upper crust and control the distribution and evolution of the Paleogene rifting. Three NE-NNE right-lateral strike-slip faults are superposed on the extensional system. These strike-slip faults and their associated structural elements form the Cenozoic strike-slip tectonic system. The extensional system is a “horizontal layered” thin-skinned tectonics at the crustal scale. The normal faults converge toward great depths or terminate at the detachment fault surfaces within the mid-crust. The strike-slip system is a “vertical belt-like“ thick-skinned tectonics at the crust scale. The strike-slip faults at the shallow level of the crust are merged into the deep fault zones in several ways. The two tectonic systems are concrete manifestations of the active rifting and passive rifting mechanisms in the basin during the Cenozoic.
    16  The plateau and continental dynamics: A QinghaiTibet review on terrain tectonics, collisional orogenesis, and processes and mechanisms For the rise of the plateau
    XU Zhiqin ,  YANG Jingsui Haibing ,  LI ,  ZHANG Jianxin ,  ZENG Lingsen ,  JIANG Mei
    2006, 33(2):221-238. DOI: 10.12029/gc20060201
    [Abstract](3682) [HTML](0) [PDF 2.08 M](5234) [Cited by](53)
    Abstract:
    Abstract:Recent studies on the compositions and structures of multiple terrains within the plateau have offered us an QinghaiTibet opportunity to examine how this plateau was assembled in the context of terrain tectonics. The formation of this plateau resulted from tectonic activities since the late Longterm Paleozoic which is represented by (1) convergence and welding of A number of exotic terrains, and (2) collision induced "orogenic plateaux" and has reached its climax in the Cenozoic. faults (commonly Largescale Strikeslip act as terrain boundary faults) has played a central role in controlling the relative offset, magnitude of lateral extrusion, and the geometry of these terrains. The final assembly and rise of the QinghaiTibet Plateau May result from a combination of contemporaneous processes, e.g. Superdeep subduction (> 600 km) at its southern margin subduction at its northern margin, Intracontinental Inland, deep thermal processes, and lateral uplift of mantle lithosphere. NEtrending Right.
    17  Dating of gabbro in the Shemalagou ophiolite in the western segment of the Bangong Co-Nujiang ophiolite belt, Tibet—with a discussion of the age of the Bangong Co-Nujiang ophiolite belt
    QIU Rui-zhao ,  ZHOU Su ,  DENG Jin-fu ,  LI Jin-fa ,  XIAO Qing-hui ,  CAI Zhi-yong
    2004, 31(3):262-268. DOI: 10.12029/gc20040304
    [Abstract](2822) [HTML](0) [PDF 848.86 K](5648) [Cited by](53)
    Abstract:
    Abstract: Sm-Nd and K-Ar dating of layered gabbro in the Shemalagou ophiolite in the western segment of the Bangong Co-Nujiang ophiolite belt indicates a combined internal and whole-rock Sm-Nd isochron age of 191±22 Ma and K-Ar ages of 140±4.07 Ma and 152.30±3.60 Ma. According to the dating results, combined with geological data, it is suggested that the Sm-Nd age represents the age of ocean basin opening, i.e. Early Jurassic, while the latter is the time of alteration influenced by the subduction of oceanic crust. Based on the available data in the central and eastern segments of the Bangong Co-Nujiang ophiolite belt, the ages of opening, subduction and closing of the ocean basin are discussed. The authors think that the Bangong Co-Nujiang ocean basin probably opened from east to west simultaneously in the Early Jurassic, began to be subducted southward in the Middle Jurassic and finally closed at the end of the Early Cretaceous.
    18  SHRIMP U-Pb geochronology of the Xinqiao Cu-S-Fe-Au deposit in the Tongling ore district， Anhui
    WANG Yan-bin，Liu Dunyi，MENG Yi-feng，ZENG Pu-sheng，YANG Zhu-sen，TIAN Shi-hong
    2004, 31(2):169-173. DOI: 10.12029/gc20040208
    [Abstract](2927) [HTML](0) [PDF 519.74 K](3629) [Cited by](51)
    Abstract:
    Abstract：High-precision SHRIMP U-Pb dating was performed on zircon from quartz diorite and diabase in the Xinqiao Cu-S-Fe-Au deposit， Tongling ore district， Anhui. Zircon from quartz diorite yielded a 206Pb/238U age of (140.4±2.2) Ma， while the zircon age of diabase is relatively complex. Several Proterozoic zircon grains were found in diabase， which yielded 207Pb/206Pb ages of (2 261±14) Ma， (1 612±8) Ma， (919±12) Ma and (831±17) Ma. In addition， there is also a group of Early Paleozoic zircon grains， whose 206Pb/238U age is (443±13) Ma. The above new data give the information of the possible existence of Proterozoic basement in this district， and Yanshanian magmatism is of great significance for mineralization in the district.
    19  The lithosphere structure in the Hingmong-Jihei (Hinggan-Mongolia-Jilin-Heilongjiang) region, northeastern China
    ZHANG Xing-zhou ,  YANG Bao-jun ,  WU Fu-yuan ,  LIU Guo-xing
    2006, 33(4):816-823. DOI: 10.12029/gc20060411
    [Abstract](3639) [HTML](0) [PDF 1001.93 K](4699) [Cited by](49)
    Abstract:
    Abstract:The lithosphere beneath the Hingmong-Jihei (Hinggan-Mongolia-Jilin-Heilongjiang) region, northeastern China, is composed of the Ergun, Hinggan, Songneng and Jiamusi continental blocks and Mesozoic Wandashan accretionary complex. Nd isotope model ages indicate that: the Nd model age of the Jiamusi block is oldest, being 1500-2200 Ma; the age of the Ergun block comes next, being 1000-1600 Ma; and the Hinggan block and Songnen block have the same Nd model age, ranging from 500 to 1200 Ma. Geochemical tracing analysis indicates that the Nd isotope model age of Paleozoic supracrustal rocks is dominantly Mesoproterozoic, while that of Mesozoic granites is mainly Neoproterozoic. Therefore, it is concluded that the deep level of the crust is younger than the surficial level of the crust, indicating that the crust in the region has an age structure of being younger in the lower part and older in the upper part. The Os isotope analysis also indicates that the lithospheric mantle in this region also shows the younger character. The seismic (Vp) velocity structure shows that vertically the lithospheric structure in the region has the following two prominent features: (1) notably different from the traditional concept of the seismic lithosphere, the low-velocity zone of the lithospheric mantle has no persistent and continuous top interface which the low-velocity anomalous top is highly varied in depth and interlocks with the high-velocity anomalous bodies, and the low-velocity anomalies below some tectonic units may reach the Moho but the bottom interface occurring at 230-240 km depth is very persistent; and (2) the “overpass-type” velocity structure is manifested by the following: the velocity contours are generally distributed in a NE direction in the crust, in a NNW-NS direction in the lithospheric mantle and in a nearly E-W direction in the low-velocity anomaly asthenosphere.
    20  Geological characteristics of the Pulang porphyry copper deposit, Yunnan
    FAN Yu-hua ,  LI Wen-chang
    2006, 33(2):352-362. DOI: 10.12029/gc20060214
    [Abstract](4068) [HTML](0) [PDF 1.26 M](7304) [Cited by](49)
    Abstract:
    Abstract：The Pulang porphyry copper deposit is located on the eastern margin of the Dege-Zhongdian block on the western side of the Garze-Litang junction zone, in the southern segment of the Indosinian Yidun-Zhongdian island-arc belt. The strata of the copper district are the Upper Triassic Tumugou Formation, and there mainly outcrops the Indosinian Pulang composite intermediate-acid porphyry. Structural fissures are well developed and rocks are strongly altered, showing typical “porphyry type” alteration zoning with intense silicic alteration zone → silicic-potassic alteration zone → phyllic alteration zone → propylitic alteration zone from the center outward. Magmatic rocks, strata emplaced by magma, hydrothermal alteration and structural space for hydrothermal fluid transport and deposition of ore substances controlled the occurrence of this deposit. The mineralization occurred in the Pulang composite porphyry and mineralization and alteration occur in company. A pipe-shaped orebody composed of veinlet-disseminated ores formed in the center of the intrusion and vein-shaped orebodies formed at edges of the intrusion. The dominant ore element of the deposit is copper, with many subordinate useful components such as gold, silver, molybdenum, palladium and sulfur. The deposit reaches the superlarge size.
    21  Cretaceous：A key transition period of the plate tectonic evolution in China and its adjacent areas
    WU Gen-yao
    2006, 33(1):64-77. DOI: 10.12029/gc20060107
    [Abstract](2574) [HTML](0) [PDF 1.82 M](4375) [Cited by](46)
    Abstract:
    Abstract：The Asian continent (mainland China and its adjacent areas) is a composite one formed by multi-stage accretion and collision of a number of microcontinents (cratons) and blocks of different origins. The Hercynian-Indosinian cycle and Neo-Tethyan cycle played a decisive role in its formation. At the end of the Jurassic and the beginning of the Cretaceous, the Neo-Tethys ocean (which is called the Mid-Tethys by some people) closed ａｎｄ the embryonic Asian continent occurred. At the end of the Cretaceous, the Neo-Tethys ocean was consumed and the Asian continent originated；therefore the Cretaceous was an important transition period of the plate tectonic evolution of China and its adjacent areas. This paper discusses this transition in the contexts of the transitions of geodynamic system and tectonic framework, appearance of the NE-trending neogenic structures and diversity of orogeny. This transition is mainly manifested by the transformation of north-south differentiation to east-west differentiation in the region during the Cretaceous. The western part is characterized by the tectonic inheritance, while in the eastern part the neogenic structures played the main role. Geomorphologically, the region was high in the east and low in the west in the Early Cretaceous, while the present-day geomorphologic feature of being high in the west and low in the east began to appear at the end of the Cretaceous. The “basin-and-range” system also began to change significantly in the Cretaceous, which suggests that the margin of the East Asian continent was disintegrated progressively in response to its creep and dispersion toward the Pacific plate, and then the tectonics in the interior of the continent became increasingly complex. This case study further indicates that we must adhere in the tectonic concept of mobilism and reconstruct the regional tectonic evolution with the idea of dynamic evolution.
    22  Discovery of the Xileketehalsu porphyry copper deposit on the southern margin of the Altay copper metallogenic belt
    YANG Wen-ping ,  ZHANG Zhao-chong ,  ZHOU Gang ,  YAN Sheng-hao ,  HE Li-xin ,  CHEN Bai-lin
    2005, 32(1):107-114. DOI: 10.12029/gc20050114
    [Abstract](2597) [HTML](0) [PDF 929.75 K](3761) [Cited by](46)
    Abstract:
    Abstract： The Xileketehalasu copper deposit is situated on the southern margin of the Altay copper metallogenic belt, i.e., inside the original Kalaxiangeer porphyry copper belt. The preliminary study and drilling have revealed that copper orebodies are completely controlled by quartz diorite porphyry and granodiorite porphyry. The ores have veinlet and veinlet-disseminated structures. Chalcopyrite and pyrite are dominant metallic minerals with minor magnetite, bornite and specularite. Magnetite formed earlier than chalcopyrite, suggesting relatively highly oxidized magma. Its mineralization and alteration zoning essentially resemble those of typical porphyry copper deposits. K-feldspar, biotite, silicate, and pyrite alteration zones occur within the porphyry, and the quartz-sericite alteration zone is distributed in the contact between the porphyry and its wall rocks, whereas the propylitic zone occurs in the country rocks. The geochemistry of the mineralized porphyry characterizes adakite： high SiO2 (63%-66%) and Al2O3 (15%-17%), enrichment in Sr (378×10-6-447×10-6）, no negative Eu anomalies, depletion in Y（10×10-6-14×10-6）and Yb (1.3×10-6-1.5×10-6, and low initial Sr isotopic value (0.70439), high (εNd)t values (+6.9-+8.2) and low δ18OV-SMOW （<10‰）. The Rb-Sr isochron age for the porphyry is 332.8±8.5 Ma, belonging to Early Carboniferous. Its petrogenesis is related to partial melting of oceanic crust due to southward subduction of the Mongolian ocean plate. Therefore, its metallogenic geological setting is very similar to the famous supergiant porphyry copper deposits in the world. In addition, there are some copper occurrences with similar features in the surrounding areas of the deposit. Therefore the area has good ore prospects and is another potential porphyry copper belt in China.
    23  Underplating mechanism of Triassic granite of magma mixing origin in the East Kunlun orogenic belt
    CHEN Hong-wei ,  LUO Zhao-hua ,  MO Xuan-xue ,  LIU Cheng-dong ,  KE Shan
    2005, 32(3):386-395. DOI: 10.12029/gc20050306
    [Abstract](3798) [HTML](0) [PDF 988.52 K](4116) [Cited by](45)
    Abstract:
    Abstract：Triassic granites of magma mixing origin are widespread in the East Kunlun orogenic belt. They have the following common features： the composition of granites varies greatly; granites contain abundant mafic microgranular enclaves (MME); and different rock types tend to show gradational relationships. Particularly, these rocks co-exist with low-grade metamorphic rocks representing the lower crust without exception, implying that the magma was emplaced in the deep crust. In addition, basic intrusive rocks are widely developed in the area. They either occur in high-grade metamorphic rocks or occur together with granites of magma mixing origin, suggesting that partial melting of the lower crust and formation of the granites of magma mixing origin are probably related to underplating of basic magma. Take for example the Jialuhe granite—a typical granite intrusion of magma mixing origin in the East Kunlun area, the authors studied in detail its petrological, geochemical and isotope geochemical characteristics. It is concluded that the mantle-derived magma underplating was the direct cause of the formation of such granites and played an important role in the Triassic crustal growth and tectonic evolution in the East Kunlun orogenic belt. Furthermore, the genetic relation between the mantle-derived magma underplating and granites of magma mixing origin is discussed and a model of breaking-off-underplating-mixing-delamination in the setting of the thickened continental crust is constructed.
    24  Late Paleozoic tectonic evolution in Northeast China
    LIU Yong-jiang ,  ZHANG Xing-Zhou ,  JIN Wei ,  CHI Xiao-guo ,  WANG Cheng-wen ,  MA Zhi-hong ,  HAN Guo-qing ,  WEN Quan-bo ,  LI Wei ,  WANG Wen-di ,  ZHAO Xi-feng
    2010, 37(4):943-951.
    [Abstract](4433) [HTML](0) [PDF 1.99 M](7185) [Cited by](44)
    Abstract:
    Abstract：Northeast China area consists of several micro-continental blocks, such as Jiamusi Block in the southeast, Xing’an-Songliao Block in the middle, and Erguna blocks in the northwest. Studies of the suture zones between the blocks indicate that the amalgamation of these blocks ended before Late Paleozoic and formed a big continental block, i.e., Jia-Meng Block. From Late Paleozoic the cover sequences started to develop and formed a Late Paleozoic continental margin cover sequence.The tectonic setting of the southern margin of the Jia-Meng Block was an active continental margin during early Paleozoic. The Paleo-Asian ocean plate broke down during the northward subduction around 320 Ma, and formed a volcanic arc. Meanwhile the Hegenshan back-arc basin ocean was opened. The continuous northward subduction resulted in the arc-continent collision, and the Hegenshan Ocean was closed at 280 Ma. The tectonic setting changed from active margin to passive margin. Finally the Paleo-Asian ocean was closed at the end of Late Permian, and the whole area became an intracontinental terrestrial setting.
    25  Uplift dynamics of the Qinghai-Tibet Plateau and Altun fault
    GE Xiao-hong ,  LIU Yong-jiang ,  REN Shou-mai , 
    2002(4):346-350. DOI: 10.12029/gc20020402
    [Abstract](3011) [HTML](0) [PDF 164.88 K](5285) [Cited by](43)
    Abstract:
    Abstract: The last-phase and strongest uplift of the Qinghai-Tibet plateau occurred at 1-0.8Ma BP, which was related to the Australasian meteorite impact event in the triple junction of the Indian Ocean ridge. The impact event resulted in rapid spreading of the Indian Ocean ridge and strong A-subduction of the Indian plate beneath the Siwalik. The strong subduction gave rise to the rapid uplift of the Qinghai-Tibet Plateau and its surrounding mountains, thus forming the basin-range geomorphology in western China. The eastern Kunlun Mountains were elevated approximately 3000 m by the thrust system and meanwhile moved ~ 400km to the north, which should be responsible for the Cenozoic deformation in the Qaidam basin and Hexi corridor. Therefore, this impact event can interpret the last phase of the uplift of the Qinghai-Tibet Plateau and geodynamic background of the formation of continental tectonics of western China. 40Ar/39Ar dating of neogenic minerals during deformation suggests that the strike-slip movement of the Altun (Altyn) fault may have started at 97-89Ma, occurring nearly synchronously with the formation of the "Western tectonic node" in the Nepal-western Kunlun area The Altun strike-slip fault has a cumulative offset of 350-400km and displaced the original tectonic belts and basins in the Late Cretaceous-Cenozoic, which provides a new idea for mineral, oil and natural gas searching in western China.
    26  North China block, Jiao-Liao-Korea block and Tanlu fault
    QIAO Xiu-fu ,  ZHANG An-di
    2002(4):337-345. DOI: 10.12029/gc20020401
    [Abstract](3078) [HTML](0) [PDF 366.51 K](5096) [Cited by](43)
    Abstract:
    Abstract: In the Sinian (680 Ma), the Sino-Korean plate began to break up into two different tectonic units, the Jiao-Liao-Korea block (JLKB) and North China block (NCB). The boundary of the two blocks is called the Paleo-Tanlu fault (PTLF). The position of this fault is coincident with he present Tanlu fault, which extends from Hefei northward via the Bohai Sea to east of Shenyang and then turns NE and goes to southern Jilin. Strong earthquake records in Sinian carbonate rocks in the vicinity of the PTLF and corresponding diabase emplacement are basic geological evidence for the intraplate break-up of the Sino-Korean plate. The break-up period of the PTLF (intraplate seismic zone) is consistent with that of Proterozoic Rodinia. Archean basement rocks in the two blocks are different and the Proterozoic and Paleozoic histories of the two blocks on the eastern and western sides of the PTLE are different. The two blocks were again amalgamated in the Late Carboniferous Moscovian stage. The Rimjin River zone on the central Korea Peninsula was considered the eastward extension of the Dabie-Jiaonan orogenic belt. However, the Rimjin River zone is only an ordinary fault and China's Jiaonan ultrahigh-pressure belt bas not been found on the Korea Peninsula. Considering the similarity in the Paleozoic between the southern main area of ??the Korea Peninsula and the Liaodong Peninsula, the southern boundary of the Sino-Korean plate, i. e. the southern boundary of the JLKB is placed on Jizhou Island south of the Korea Peninsula in the paper. It joins the Jiaonan orogenic belt with the presumed Yellow Sea transform fault. Diamondiferous kimberlites in Wafangdian (originally called Fuxian County) of Liaoning Province and Mengyin of Shandong Province are distributed on the eastern and western sides of the Tanlu fault over a longitudinal distance of ~ 550km. The age of the kimberlites in the two areas ranges from 500 to 450Ma, i. e. the rock was emplaced at the end of the Middle Ordovician. Since the kimberlites in the two areas have similarities in some aspects such as petrography, mineralogy and emplacement age and are both close to the Tanlu fault, some geologists think that the kimberlites of the two areas were possibly very close to each other during their emplacement and belong to the same province; therefore they always explain the distance letween the Wafangdian and Mengyin kimlerlite provinces with the great displacement of the Tanlu fault. The Tanlu fault is a deep fault cutting through the lithosphere. Comparison of the differences and similarities between the lithosphere profiles of Wafangdian and Mengyin provides significant evidence for judging whether the Tanlu fault has a great displacement. Study of the mantle samples in the kimberlites reveals that the profiles of the paleo-lithosphere that the kimberlites in the two areas cut through during their emplacement are very different. This indicates that the two areas are neither contiguous nor close to each other at that time. On the basis of the above-mentioned sample study, combined with the new understanding got from a study of the regional geological structure, the authors find that the two kimberlites were actually emplaced separately into two different tectonic units of the Sino-Korean plate and the distance between the two areas is independent of displacement. This finding does not support the view of the great displacement caused by the Tanlu fault.
    27  The Dur’ngoi ophiolite in East Kunlun, northern Qinghai-Tibet Plateau: a fragment of paleo-Tethyan oceanic crust
    YANG Jing-sui ,  WANG Xi-bin ,  SHI Ren-deng ,  XU Zhi-qin ,  WU Cai-lai
    2004, 31(3):225-239. DOI: 10.12029/gc20040301
    [Abstract](3285) [HTML](0) [PDF 1.49 M](5154) [Cited by](43)
    Abstract:
    Abstract:The Dur’ngoi ophiolite in the north Qinghai-Tibetan Plateau consists of meta-peridotite, mafic-ultramafic cumulate, sheeted dikes and basaltic lavas. The meta-peridotite consists of dunite, harzburgite, lherzolite, feldspar-bearing lherzolite and garnet-bearing lherzolite and contains residual spinel with Cr#s [100*Cr/(Cr+Al)] of 30-57 and Mg#s [100*Mg/(Mg+Fe2+)] of 50-75, indicating an Al- and Mg-rich series. The meta-peridotites have a relatively narrow range of composition with Mg#s of 89.2-92.6, Al2O3 contents of 1%-4 % and slightly depleted REE patterns, indicating that they represent relict mantle material that has undergone intermediate to low degrees of partial melting. Garnets in the lherzolite are andradite enriched in Ca and Fe and depleted in Mg and Al (And 95-97, Pyr 0.27-5.06,Gro 0-2.62), indicating that they formed by metamorphism. Cumulates consist mainly of dunite, wehrlite, pyroxenite and gabbro. The dunite contains minor feldspar, mostly replaced by chlorite and clay minerals. The wehrlite consists of olivine, diopside and minor plagioclase. A well-layered gabbro-pyroxenite complex is defined by variations in modal plagioclase and pyroxene. Blocks of garnet-pyroxenite or rodingite are locally present in the meta-peridotite. Garnets in the cumulates are grossular (Gro 69.19-89.93；And 9.12-18.84；Br 0.73-11.63), formed by metamorphism. Diabase dikes are depleted in LREE with (La/Sm)N ratios of 0.49-0.75 and have flat HREE patterns with positive Eu anomalies (δEu =1.14-1.27). Basalts have REE patterns similar to those of MORB with (La/Sm)N ratios of 0.46-0.95 and small negative Eu anomalies. The basalt compositions, particularly their consistent REE patterns, suggest no contamination in their magma source and little differentiation during crystallization. SHRIMP U-Pb dating of zircons from the basalts yielded 206Pb/238U ages of 276-319 Ma (average 308.2±4.9 Ma). The Dur’ngoi ophiolite is interpreted as a dismembered fragment of paleo-oceanic crust formed at a fast-spreading mid-ocean ridge. Intense serpentinization and carbonization reflect hydrothermal alteration on the seafloor associated with formation of the Dur’ngoi Cu-Co-Zn massive sulfide deposit. The ophiolite was probably emplaced during closure of the paleo-Tethyan ocean basin and is believed to mark the suture between Gondwana and Eurasia.
    28  Early Mesozoic geotectonic processes in South China
    XU Xian-bing ,  ZHANG Yue-qiao ,  JIA Dong ,  SHU Liang-shu ,  WANG Rui-rui
    2009, 36(3):573-593.
    [Abstract](4259) [HTML](0) [PDF 8.23 M](7492) [Cited by](43)
    Abstract:
    Abstract：South China experienced intense tectonic deformation and magmatism in Early Mesozoic, which resulted in profound change of the geodynamic regime. The processes and settings of the early Mesozoic geotectonic processes have long been a subject of controversy. Based on a summarization of previous research achievements, this paper deals with tectono-sedimentary layers, Early Mesozoic tectonic deformation styles and magmatic sequence, with the purpose of distinguishing between Indosinian and early Yanshanian tectonic events as well as their geological effects. It is shown that the Indosinian tectonic event occurred in Middle-Late Triassic (245~225Ma) and was featured by nearly EW-trending fold-and-thrust belts and NE-NNE striking ductile shear zones, which were dynamically related to the Triassic collision between the South China Block and the North China Block along the Qingling-Dabie orogenic belt and also to the subduction and accretion of plaeo-Tethys oceans along the southern margin of the South China Block. The basement of the Caledonian folded zone in eastern South China was intensely rejuvenated, and crustal melting occurred particularly in the Shiwan Mountains-Yunkai Mountain-Wuyi Mountain tectonic zone and Xuefeng area. Early Jurassic (205~190 Ma) marks an era of quiescence of magmatic activity in South China, whereas late Early Jurassic (190~180 Ma) was characterized by A-type granite emplacement and bimodal volcanic activity along the WE-trending Nanling belt. Early Yanshanian tectonic event commenced around 170 Ma in late Middle Jurassic, which caused the formation of a ~1300-km-wide, NE-NNE-trending fold-and-thrust system in South China. Crustal thickening and crust-mantle interaction led to the remobilization of Cathaysian Block and induced intense magmatic activities, with the development of a volcanic arc in southeastern China. This event was related to the low angle subduction of an oceanic plate under the South China Block, which led to a subsequent series of late Mesozoic intracontinental tectonic processes and magmatic activities.
    29  Major breakthrough in copper exploration in the Baogutu porphyry copper deposit, western Junggar, Xinjiang, and its significance
    ZHANG Rui ,  ZHANG Yun-xiao ,  TONG Geng-sheng ,  WANG Jiang ,  LI long-qian
    2006, 33(6):1354-1360.
    [Abstract](4107) [HTML](0) [PDF 827.57 K](4919) [Cited by](39)
    Abstract:
    Abstract：Volcanic-hosted gold and ophiolite-hosted chromite were previously the focus of long-term exploration and research in the Toli ore belt, western Junggar, Xinjiang. In 2001-2004, a major breakthrough was made in copper exploration in the Baogutu area. The Baogutu copper deposit is closely related to Hercynian granodiorite porphyry. The ore has a simple metallic mineral composition and finely disseminated and veinlet-disseminated structures. The ore grade is low, the mineralization is homogeneous and the alteration assemblage and zoning are pronounced. According to the above-mentioned features, the deposit belongs to a typical porphyry copper-molybdenum deposit. The discovery of the Baogutu porphyry copper deposit is the first-ever discovery of a copper deposit in western Junggar. It proves that the Balkhash porphyry copper belt of Kazakhstan extends eastward into the Junggar area of China, which has great significance for advancing mineral exploration in this new prospect area.
    30  Ore-system as a geodynamic probe
    CHEN Yan-jing ,  XIAO Wen-jiao ,  ZHANG Jin-jiang
    2008, 35(6):1059-1073.
    [Abstract](2622) [HTML](0) [PDF 3.58 M](3869) [Cited by](37)
    Abstract:
    Abstract：In this paper we introduce several breakthroughs in geodynamic or tectonic issues resulted from studies on ore-systems, and propose that ore-systems can serve as an ideal geodynamic probe. Usually formed in multiple geological processes, ore-systems record complete geological information. Compared to other kinds geologic bodies, ore-systems are more precisely studied through prospecting and/or mining. As a consequence, ore-systems can provide accurate indicators to geodynamic settings and evolution. We set up a preliminary linkage between major ore-systems and geodynamic settings; and propose several important scientific approaches for solving long-standing geodynamic controversies by the study of ore-systems.
    31  Pb-Zn depsits on the perimeter of the Yangtze craton and on the margins of its uplifts
    RUI Zong-yao ,  YE Jin-hua ,  ZHANG Li-sheng ,  WANG Long-sheng ,  MEI Yan-xiong
    2004, 31(4):337-346. DOI: 10.12029/gc20040401
    [Abstract](2834) [HTML](0) [PDF 1.23 M](4849) [Cited by](37)
    Abstract:
    Abstract：The Yangtze paraplatform is a large craton characterized by development of carbonate formations. Typical Sinian to Middle Triassic cover sediments contain many carbonate formations. Many stratabound Pb-Zn deposits have been found in the carbonate formations on the perimeter of the Yangtze craton and on the margin of its uplifts since the founding of the People＇s Republic of China. In recent years, with the large-scale geological survey,an additional group of very promising Pb-Zn mineralization concentration areas have been discovered in the region. This paper sums up the geological features of these Pb-Zn deposits, compares them with MVT deposits abroad and discusses their ore material source, ore fluids, genetic mechanism and ore controlling factors.
    32  Some thoughts on the study of continental dynamics and orogenic belts
    ZHANG Guo-wei ,  DONG Yun-peng ,  YAO An-ping
    2002(1):7-13. DOI: 10.12029/gc20020102
    [Abstract](3660) [HTML](0) [PDF 101.58 K](5275) [Cited by](36)
    Abstract:
    Abstract: According to the demands of the human society and China's economic development, as well as the new development of contemporaneous geoscience, the authors analyze and discuss the academic concepts, starting point, scientific aim and key issues, as well as the main research content and methods about the study of the continental dynamics and orogenic belts of China, and put forward some suggestions. To face the opportunity and challenge of geoscience, the authors consider that we should formulate the strategy of the study of geoscience. In addition, according to the fact of China's continental geology, we should put emphasis on the study of the key scientific problems of China's continental dynamics, establish sustained research bases and analyze typical examples and make breakthroughs of key issues. With the study of continental dynamics as a breakthrough point, we should renovate the study of geoscience, participate in the development and competition of international geoscience and strive to enter the advanced rank of geoscience study in the world and become a strong power in geoscience, so as to make China's due contribution.
    33  Cenozoic tectonic sequence and tectonic events at?the eastern margin of the Qinghai? Juan Tibet plateau
    Li Yong ,  HOU Zhong-jian ,  Si Guang-ying ,  A. L. DENSMORE Zhou Rong-jun ,  M. A. ELLIS ,  LI Yong-zhao ,  Liang Xing-zhong
    2002(1):30-36. DOI: 10.12029/gc20020105
    [Abstract](4114) [HTML](0) [PDF 155.93 K](6777) [Cited by](35)
    Abstract:
    Abstract: The eastern margin of the Qinghai-Tibet plateau can be divided into four tectonic units; from northwest to southeast, they are the Songpan-Garzê orogenic belt, Longmenshan-Jinpingshan thrust belt, foreland basin and Longquanshan forebulge, which are cut by the Xianshuihe fault. Cenozoic intermontane basins are developed in the inner part of the Longmenshan? Juan Jingpingshan Thrust Belt, and a Foreland basin occurs along the frontal part of the thrust belt. The Cenozoic sedimentary record along the margin is a key to constraining the plateau uplift and evolution during the collision and continued convergence of India and Eurasia during the last 65Ma. Cenozoic sediments in the basin of the eastern margin can be classified into five tectonic sequences. Sequence 1 is composed of Paleocene to early Eocene red beds (65 ~ 55Ma) and represents a fining? Juan the Upward retrogressive cyclothem in the Foreland basin, with alluvial fan sediments in the lower part and playa sediments in the upper part. Sequence 2 is composed of Middle-Late Eocene red beds (50 ~ 40Ma) and represents a retrogressive and progressive cyclothem in the Yanyuan intermontane basin, with alluvial fan sediments in the lower and upper parts and fluvial sediments in the middle. Sequence 3 is composed of Miocene coal? Juan of bearing beds (23 ~~ 16mA) and a represents a coarse-Upward progressive cyclothem in the Foreland basin, with alluvial fan and lacustrine sediments. Sequence 4 is composed of the Pliocene? Juan Early the Pleistocene Yanyuan Formation (4.29 to 2.58Ma) or Dayi conglomerate (3.6 to 1.7mA) and represents a fining-Upward retrogressive cyclothem, in the Foreland basin with alluvial fan sediments in the lower part and lacustrine sediments in the upper part. Sequence 5 is composed of the Middle Pleistocene Ya'an conglomerate (0.65 ~ 0.20Ma) and represents a fining-upward retrogressive cyclothem in the foreland basin. Based on the filling succession and discordant contacts between Cenozoic strata in the basin, six tectonic events along the eastern margin of the Qinghai-Tibet plateau are recognized. During each tectonic event, thrusting was followed by strike-slip deformation, which controlled basin formation, sedimentation and tectonic sequence. During the second and third tectonic events related to the Late Eocene collision between the Indian and Eurasian plates, deposition occurred within small intermontane basins. A hot, dry climate gave rise to sediments dominated by red beds interbedded with gypsum and eolian sandstone. The fourth tectonic event in Early Miocene time resulted in deposition within a foreland basin. A warm, humid climate gave rise to the deposition of lignite-bearing microclastic rocks, which was subsequently uplifted to an elevation of 2000m. The fifth began in Pliocene time, during which a large volume of fan conglomerate was deposited in the foreland basin. The sixth tectonic event in Middle Pleistocene time resulted in deposition of conglomerate in the Chengdu foreland basin.
    34  The annual average temperature in northern China
    WANG Guo-an ,  HAN Jia-mao ,  ZHOU Li-ping
    2002(1):55-57. DOI: 10.12029/gc20020109
    [Abstract](2341) [HTML](0) [PDF 116.49 K](4524) [Cited by](35)
    Abstract:
    Abstract: Four common C3 plant species-Chenpodium album, Lepidium apetalum, Cirsium leo and Plantago depressa-were sampled and their δ13C values ??were measured. The δ13C values ??of all the four plant species decrease with increasing annual average temperature, and the responses of the carbon isotopic compositions of Chenpodium album and Lepidium apetalum to temperature change are much more intense than those of Cirsium leo and Plantago depressa. Highly significant linear relationships between carbon isotopic compositions of Chenpodium album, Lepidium apetalum and Cirsium leo, but Plantago depressa, with annual temperature are observed. These results suggest that the δ13C values ??of Chenpodium album, Lepidium apetalum and Cirsium leo, but Plantago depressa, can be used as annual temperature proxies, and that Chenpodium album and Lepidium apetalum may be more suitable than Cirsium leo.
    35  Cenozoic plate tectonic activities in the Great South China Sea area
    YAO Bo-chu ,  WAN Ling ,  WU Neng-you
    2004, 31(2):113-122. DOI: 10.12029/gc20040201
    [Abstract](4115) [HTML](0) [PDF 1.04 M](7398) [Cited by](34)
    Abstract:
    Abstract: There existed some blocks (micro-plates) in the oceans between Australia and Asia in the Cenozoic, when some blocks were separated from the Australian plate and moved northward and collided and sutured with some blocks that were separated from the Eurasian plate. In this period small ocean basins such as the South China Sea, Sulu Sea, Celebes Sea and Andaman Sea formed as a result of block separation and seafloor spreading, and finally the present tectonic framework formed in the Great South China Sea area. After a study of the Cenozoic tectonic history of the Great South China Sea area, the authors believe that Cenozoic tectonic activities in the Great South China Sea were not only related to collision between the Indian Plate and Eurasian Plate but also to subduction of the Pacific Plate beneath the Eurasian Plate and were also affected by the northward movement of the Australian. Plate. In the South China Sea Basin there occurred two events of seafloor spreading in the Cenozoic. The first seafloor spreading, which was oriented in a NW-SE direction, occurred before 42-35 Ma BP under the influence of the southeastward mantle flow beneath the Eurasian continent caused by India-Eurasia collision. The first seafloor spreading gave rise to the Southwest Basin of the South China Sea. The second seafloor spreading took place before 32-17 Ma BP. As the Pacific plate was subducted beneath the Eurasian plate to 700 km depth, the SE-directed flow of the upper mantle of the Eurasian continent was blocked and then turned toward the south, thus causing N-S-trending seafloor spreading in the South China Sea area, i.e. the second seafloor spreading. The second seafloor spreading resulted in the formation of the Central Basin of the South China Sea. After the Cenozoic South China Sea Basin was produced, collision between the blocks and seafloor spreading continued in the Great South China Sea area, and under the compression of these northward blocks the south margin of the South China Sea, sediments in the area were deformed, thus producing the Wanan movement (at about 10 Ma BP) on the south margin of the South China Sea.
    36  Pre-Yanshanian geological events in the northern margin of the North China Craton and its adjacent areas
    ZHAO Yue ,  CHEN Bin ,  ZHANG Shuan-Hong ,  LIU Jian-Min ,  HU Jian-Min ,  LIU Jian ,  PEI Jun-Ling
    2010, 37(4):900-915.
    [Abstract](3540) [HTML](0) [PDF 4.53 M](4441) [Cited by](34)
    Abstract:
    Abstract：Recent researches on the northern margin of the North China Craton (NCC) and its adjacent areas have been mainly focused on the main pre-Yanshanian tectonic framework and the late Mesozoic tectonomagmatic evolution and lithosphere destruction. This paper gives a brief review on the previous research progress and future prospect in this aspect. The northern NCC has undergone multiple magmatic processes after its cratonization during ~1.8 Ga. Large volumes of 1.35-1.30 Ga mafic sill (dyke) swarms in northern NCC are related to the breakup of the NCC from the Columbia supercontinent and might indicate that the NCC was probably a member of Nena including the Laurentia (North America and Greenland), Siberia and Baltica cratons in the supercontinent. The evolution of the northern continental margin of the NCC was probably initiated at 1.35 Ga. During the Early Paleozoic, the Bainaimiao island arc belt was located to the south of the NCC. At the end of Early Paleozoic, the island arc was accreted to the NCC probably by arc-continental collision. Early-Middle alkaline complexes with emplacement ages ranging from 410-380 Ma in northern NCC are probably related to the extension after arc-continental collision between the NCC and the Bainaimiao arc terrane. From the Late Carboniferous (~320 Ma), the northern margin of the NCC became an Andean-style continental arc due to the southward subduction of the Paleo-Asian oceanic plate beneath the NCC. The southward subduction of the Paleo-Asian oceanic plate also occurred in the Xing-Meng orogenic belt during this period, which resulted in the formation of the Baolidao island arc. Final closure of the Paleo-Asian Ocean and collision between the Mongolian arc terrane and the NCC occurred during the latest Permian~earliest Triassic period with post-collison magmatism from ~250 Ma. During the Late Triassic~Early Jurassic period, the northern NCC is characterized by strong thrusting. In the early Jurassic, the Archean-Paleoproterozoic basement metamorphic rocks were widely exposed. The tectonic framework of the northern margin of the NCC and its adjacent areas was preliminarily established prior to the Yanshanian tectonism and magmatism.
    37  Mesozoic-Cenozoic tectonic framework of southern Northeast Asia
    GE Xiao-hong ,  MA Wen-pu
    2007, 34(2):212-228.
    [Abstract](2718) [HTML](0) [PDF 3.70 M](3959) [Cited by](33)
    Abstract:
    Abstract：Southern Northeast Asia covers the area where the West Pacific tectonic belt, North America or Okhotsk Plate, Central Asia orogenic belt, the Sino-Korea and the Yangtze blocks meet together. In the course of Pangaea and supercontinent assembling and disintegration this belt has experienced multple tectonic events since the Mesozoic and has acquired a rather complicated structure. The tectonic affiliation of many middle-scaled and small scaled blocks, including that of the Korea Peninsula, have long been disputed. Based on recent obtained SHRIMP geochronologic data and palaeobiogeographic and tectonic evidences, the authores in this paper deem that the Korea Peninsula and the Hida-Oki belt of Japan might have been affiliated to the Sino-Korea Plate during the Paleozoic, Sakhalin-Hokkaido massifs, to the North America Plate, and the Bureya-Jiamusi-Khanka massifs, to Siberia Plate. Since the 80's of last century most authors have regarded the discussed area as connected with the westward subduction of the West Pacific oceanic crust under Northeast Asia since the Mesozoic. But recently more and more scholars prefer to interpret the geodynamics of crust-lithospheric thinning of Eastern Asia from continent collision and extrusion. The southern Northeast Asia belt has experienced two stages of tectonic development: consumption of the Palaeo-Asian Ocean during the late Hercynian-Indosinian epoch and convergence-collision between the southern and the northern continents during the late Yanshanian epoch (late Jurassic to early Cretaceous). It was these processes that resulted in the extension of the Central Asia orogenic belt to the Yinshan-Yanshan region at the northern edge of the Sino-Korea plate and the formation of a plateau morphology caused by crustal thickening similar to the Qinghai-Tibet Plateau today. In the late Cretaceous to Palaeogene, the crust-lithosphere thinning of this area caused the appearance of large scale extension type Basin-Range structure. In the meantime, the northward section of the Tanlu faults system underwent sinistral displacement. Along the East Asia continental margin occurred accretion, and the rotation of the Pacific plate caused compressional deformation and extensive peneplanation. Many heavy metal and noble metal placeres in the fault basins bordering Palaogene uplifts in Heilongjiang and Jinin were formed in this period. In the Neogene the crust-lithosphere further thinned and the continental rifts developed into the East Asia-Pacific rift belt and the NNE-trending Basin-Range structure came to appear. The Sea of Japan opened, the Western Pacific island arcs appeared. The recent topographic steps of China was initiated at the end of the Early Pleistocene. But the present geomorphic frame that controls the nowadays climate and river system was not formed until post-late Pleistocene time.
    38  Framework of Mesozoic tectonic evolution in southeastern Hunan and the Hunan-Guangdong-Jiangxi border area
    BAI Dao-yuan ,  HUANG Jian-zhong ,  LIU Yao-rong ,  WU Guang-yinｇ ,  MA Tie-qiu ,  WANG Xian-hui
    2005, 32(4):557-570. DOI: 10.12029/gc20050404
    [Abstract](2491) [HTML](0) [PDF 1.66 M](5769) [Cited by](33)
    Abstract:
    Abstract：Southeastern Hunan and the Hunan-Guangdong-Jiangx border area belong to the northern part of the central segment of the Nanling Range. This region is a favorable window for studying Mesozoic tectonic setting and evolution in South China. According to isotopic chronological, geological and geochemical studies, the time ranges and tectonic settings of granites of three Mesozoic ages are determined, and on that basis, combined with the characteristics and genetic mechanism of continental basins of different Mesozoic ages and volcanic rocks, stages and characteristics of tectonic deformations and ore-forming processes, a preliminary sequence framework of the Mesozoic geological events is defined. Four major stages of Mesozoic tectonic evolution in the region may be distinguished; from early to late times they are the Early Triassic－early Middle Triassic pre-orogenic stage (I), the late Middle Triassic–early Middle Jurassic intracontinental orogenic stage (Ⅱ), the early Middle Jurassic–Late Jurassic post-orogenic stage (Ⅲ), and the Cretaceous intraplate rift stage (Ⅳ). ｏf these，stage II may be further divided into four substages (Ⅱ1–Ⅱ4). The pre-orogenic stage (Ⅰ) was a stable marine sedimentary stage. The late Middle Triassic (Ⅱ1) was an intracomtinental subduction-converge peak stage, when a great deal of mainly NNE-directed thrusts and folds formed, resulting in crustal thickening. In the terminal Middle Triassic–latest Triassic (Ⅱ2）, compression was relatively relax and a great deal of crustal-derived granitic magma formed and was emplaced (233–210 Ma). There was a syn-orogenic uplift-extensional tectonic setting in the terminal Late Triassic–Early Jurassic (Ⅱ3), when the NNE-directed rift coal-bearing basins formed and high-Na and low-K tholeiitic magma was erupted. The initial Middle Jurassic (Ⅱ4) witnessed NNE-directed sinistral convergence-strike-slip orogeny, when thrusts formed and early-formed rift basins underwent inversion to transform to piedmont thrust-contractive basins. In the early Middle Jurassic－Late Jurassic post-orogenic stage (III), voluminous post-orogenic granite was emplaced (at 174－135 Ma), accompanied by extensive mineralization. At the end of the Jurassic there occurred a transient compression event. In the Cretaceous intraplate-rift stage (Ⅳ), there occurred such tectonic associations as basin-range tectonics and metamorphic core complexes, bimodal volcanic rocks and subvolcanic rocks, acid dikes and Shangbao small intrusions with the characteristics of AA-type granite. Finally, the paper discusses the early Yanshanian tectonic environment and the formation mechanism of tectono-magmatic characteristics of different stages in the Mesozoic in South China.
    39  Magmagenesis of Ordovician back-arc basins in the Northern Qilian Mountains
    XIA Lin-qi ,  XIA Zu-chun ,  XU Xue-yi
    2003, 30(1):48-60. DOI: 10.12029/gc20030105
    [Abstract](3399) [HTML](0) [PDF 1.51 M](4448) [Cited by](33)
    Abstract:
    Abstract: This paper reports the results of a petrogeochemical study of lavas in lower Paleozoic back-arc basins in the Northern Qilian Mountains. The distribution of samples links regions of back-arc seafloor spreading to the north with regions farther south where a progression of island arc rifting styles occurred in the earliest stage of back-arc basin extension. Petrographic and geochemical characteristics of lavas reflect the change in style of extension, with typical back-arc basin basic lavas in the north passing southward to arc lavas. Glassy (devitrified now), minor-porphyritic basic lavas characterize regions of seafloor spreading. Felsic lavas and porphyritic basic lavas occur in the southern, island-arc rifting regions. Geochemically, mature arc portions (Y<20×10-6, TiO2<0.60%, Th/Yb>0.60) are distinguished from regions of back-arc spreading (Y>20×10-6, TiO2>1.0, Th/Yb<0.60). Samples show progressive marked changes in geochemical compositions, from back-arc basin basic lavas formed by seafloor spreading southward through lavas that increasingly resemble arc lavas to arc lavas that are indistinguishable from arc lavas encountered in the southernmost portion of the rift. These changes reflect the changes in the mechanism of mantle convection and processes of melt generation beneath the evolving back-arc basin in the Northern Qilian Mountains: from mantle downwelling beneath incipient island arc rifts caused by slab subduction to mantle upwelling beneath zones of back-arc seafloor spreading. The rift axis captured the arc magmatic flux in the early island arc rift stage, so that the lavas erupting from this part of the rift cannot be compositionally distinguished from arc lavas. As back-arc extension continued and the back-arc basin widened, the arc magmatic flux moved progressively away from the rift axis, finally generating a mid-ocean ridge-like decompression melting system-back-arc basin magmatic system.
    40  Structure and dynamics of lithosphere and asthenosphere in the gigantic East Asian-West Pacific rift system
    CAI Xue-lin ,  ZHU Jie-shou ,  CAO Jia-min ,  YAN Zhong-qiong ,  YANG Zheng-xi ,  Hong Xue-hai , 
    2002(3):234-245. DOI: 10.12029/gc20020302
    [Abstract](2952) [HTML](0) [PDF 7.79 M](4851) [Cited by](33)
    Abstract:
    Abstract: Based on the seismic S-wave tomography, the authors carried out a systematic study of the speed structures of the lithosphere and asthenosphere of Eurasia and the West Pacific, and found a gigantic low-velocity anomaly zone between East Asia and the West Pacific . According to this discovery, combined with the tectonic, mantle petrological and geochemical characteristics, as well as other geophysical features, a mega-rift system is defined in the region. The 3D seismic Vs speed structures of the lithosphere and asthenosphere are very similar to those of the Mid-Pacific, Mid-Atlantic, and Mid-Indian ridges and their neighboring regions, but notably different from those of the present plate subduction zone on the East Pacific margin. On the basis of a further discussion on the dynamic characteristics of this region, it is concluded that the rift system resulted from the massively active extensional deformation and strong delamination and thinning of the lithosphere, formation of large rift basins, and upwelling and heating of a large amount of the asthenospheric substances since the Mid-Late Mesozoic. Marginal seas developed on the basis of the continental rift system, and the main extension stage is determined to be from the middle Oligocene to middle Miocene (32-13Ma). The extensions of these marginal seas had ended after the period from 17 to 15Ma; as a result not all of the seas were connected with the mid-ocean ridges. Four stages of the tectonic-deformational dynamic evolution may be distinguished, and it is considered that the tectonic superposition of interactions of various neighboring plates resulted in the formation of the continental rifts, marginal seas, and trench-arc-basin systems between present East Asia and the West Pacific since the Mid-Late Cenozoic.
    41  Some characteristics of oil and gas accumulation in the Kuqa depression, Tarim basin
    QIN Sheng-fei ,  JIA Cheng-zao ,  TAO Shi-zhen
    2002(1):103-108. DOI: 10.12029/gc20020116
    [Abstract](4074) [HTML](0) [PDF 207.98 K](6828) [Cited by](32)
    Abstract:
    Abstract: There exist 6 sets of hydrocarbon source rocks with a great gas generation potential in the Kuqa depression, which provide plenty of gas for gas accumulation in the depression. Tectonic movements generated a series of fractures, which get the deep gas source rocks connected and provide good conduits for the migration of natural gas from deep source rocks to reservoirs. Due to the influence of many factors, the phase states of oil and gas in the Kuqa depression are of very uneven distribution. Multiple phases of petroleum accumulation occurred in the Kuqa depression, but the last phase was the most important. Gas accumulation occurred relatively late in the Kuqa depression. The Kuqa depression mainly yields gas; however, a part of oil deposits or oil and gas deposits are residual ones, which is the result of diffusion of large amounts of gas. Because of the difference in preservation conditions between the Kuqa depression and the Turpan-Hami basin, the Kuqa depression is gas-prone while the Turpan-Hami basin is oil-prone.
    42  Indosinian tectonic setting, magmatism and metallogenesis in Qinling Orogen, central China
    CHEN Yan-Jing，
    2010, 37(4):854-865.
    [Abstract](3884) [HTML](0) [PDF 2.47 M](4609) [Cited by](32)
    Abstract:
    Abstract：The Qinling Orogen in central China has been a long-term geologicalyl studied focus for its unique tectonic location, complicated geological history and abundant mineral resources. In previous studies geologists have clarified its tectonic framework, outlined its geological evolution, and reached a consensus that the final transition from marine basin to intracontinental mountains occurred in Indosinian (Triassic：251~199.6 Ma). However, the details of basin-to-mountain transition process, the age of final oceanic closure, the nature of Triassic tectonic setting, and the associated magmatism and mineralization in the area have been poorly constrained and hotly debated. Based on a comprehensive re-assessment of results from geological, geophysical, geochemical and ore deposit studies, the author compares the Triassic Qinling with present Mediterranean Sea, which contemporaneously accommodates oceanic slab subduction and intercontinental collision as well as gradual transition from oceanic subduction to intercontinental collision. The Qinling paleo-Tethys finally closed in a westward zipper-like way during the period of 230~200 Ma, and instantly followed by intercontinental collision between the Yangtze block and Qinling-North China united continents. Therefore, the Triassic tectonic setting in Qinling was neither a simple intercontinental collision, nor a post-orogenic or post-collisional regime. Indosinian magmatism was intensive in Qinling, forming igneous rocks including at least the adakites, calc-alkaline granitoids, high-K calc-alkaline granitoids, alkaline intrusions, Rapakivi-like granites, and carbonatites. These rocks show zoning spatial distribution, namely, northward from the Mian-Lue suture, the Yangshan-Yanzhiba peraluminous S-type granite belt, southern Qinling high-Mg and adakitic calc-alkaline granite belt, northern Qinling high-K calc-alkaline granite belt, and the carbonatite-alkaline intrusion belt at the southern margin of North China craton. Such Indosinian magmatites with distinctive petrologic complexity, lithologic diversity, spatial zonation and compositional polarity cannot be formed in syn- and/or post-collisional tectonic settings, but could have resulted from a northward paleo-Tethysan slab subduction along the Mian-Lue geosuture. Although the Indosinan mineralization has been ignored for a long time, a great number of Triassic ore deposits of economic significance have been recently discovered, including Molybdenum-containing carbonatite dykes, porphyries and orogenic-type quartz veins; orogenic-type, porphyry-/breccia pipe-type, and Carlin-type and Carlin-like gold deposits; and orogenic-type silver-dominant poly-metal deposits. This shows that mineralization of various genetic types strongly occurred in the transition regime from oceanic slab subduction to intercontinental collision, and that the Indosinian ore deposits are of exploration potential in Qinling Orogen.
    43  The progress in the strategic research and survey of rare earth, rare metal and rare-scattered elements mineral resources
    WANG Deng-hong ,  WANG Rui-jiang ,  LI Jian-kang ,  ZHAO Zhi ,  YU Yang ,  DAI Jing-jing ,  CHEN Zhen-hui ,  LI De-xian ,  QU Wen-jun ,  DENG Mao-chun ,  FU Xiao-fang ,  SUN Yan ,  ZHEN Guo-dong
    2013, 40(2):361-370.
    [Abstract](6865) [HTML](0) [PDF 7.59 M](7938) [Cited by](32)
    Abstract:
    Abstract：The three types of rare mineral resources include the rare earth, rare metal, and rare-scattered (dispersed) mineral resources in the project of the strategic research on three types of rare mineral resources. Since the beginning of the project, the research group has studies the distribution, geological features, exploitation, metallurgic technology, and market supply and demand of the rare mineral resources in the world. The investigation shows that the HREE resources have been consumed rapidly, the comprehensive utilization of critical dispersed metals should be improved, and the exploration for rare metal resources is urgent in China. Meanwhile, the utilization quality of the rare resources is low, the high added value products are very insufficient, and the ore dressing recovery percentage is low. Furthermore, 80% REE mines have been mined beyond the border, and 30% REE mines are accompanied by environmental pollution. In the aspect of metallogenic theory and regularity, the research shows that the ore-forming rocks of the ion-absorbing type REE deposit can extend to metamorphic rock and basic igneous rock from the conventional granitic and volcanic rock, and the distribution of endogenetic Li and REE deposits are separated in space and time. On the other hand, the project research group refreshed the analytical technique for the rare elements, and applied the high resolution remote sensing to the supervision and management of the rare resources. On the basis of research achievements, some opinions are put forward, such as the individual assessment for the 17 rare earth elements, the improvement of exploration standards, the creation of composite mineral commodity for some refractory rare resources, and the way to supervise mines and find new mines by sampling water from the river in southern Jiangxi. Also, in view of the different characteristics of the rare mineral resources, the authors suggest that the government should establish integrated exploration area for rare metal resources, planning area for the rare earth resources, and demonstration area for the comprehensive utilization of the scattered resources.
    44  Lithospheric tectonic units of China
    LI Ting-dong , 
    2006, 33(4):700-710. DOI: 10.12029/gc20060402
    [Abstract](2975) [HTML](0) [PDF 1.30 M](4680) [Cited by](31)
    Abstract:
    Abstract: In light of the principle of combining the Earth's surface tectonics with deep tectonics, the paper proposes six principles that should be followed in the lithospheric tectonic unit division. Based on the geological and geochemical characteristics, especially the characteristics shown by the geophysical field, with the Helan Mountains-Sichuan-Yunnan latitudinal tectonic belt as the boundary, the authors preliminarily divide continental China and its adjacent sea areas into two first-order lithospheric tectonic units: the Central Asian lithospheric tectonic domain and East Asian lithospheric tectonic domains, which are subdivided into six second-order lithospheric tectonic units: the Xiyu lithospheric block, Qinghai-Tibet lithospheric block, Songliao lithospheric block, North China lithospheric block, South China lithospheric block and South China Sea lithospheric block. Their main geological, geophysical and geochemical characteristics are described separately. Finally, some problems concerning the lithospheric tectonic unit division are discussed and some views are presented.
    45  Looking forward to the prospects of porphyry copper deposits in Tibet
    RUI Zong-yao ,  LU Yan ,  LI Guang-ming ,  WANG Long-sheng ,  WANG Yi-tian
    2003, 30(3):302-308. DOI: 10.12029/gc20030313
    [Abstract](2541) [HTML](0) [PDF 789.96 K](5082) [Cited by](31)
    Abstract:
    Abstract：Porphyry copper deposits in the world are confined mainly to the Mesozoic-Cenozoic circum-Pacific belt and Paleo-Tethys belt and Paleozoic Central Asia-Mongolian belt, where convergent plates are developed. Tibet is one of the best developed regions of convergent plates in the world, in which the Jinshajiang, Yarlung Zangbo and Nujiang-Bangong Co suture zones lie. These suture zones have a long history of oceanic plate subduction and continent-continent collision with well-developed tectonomagmatic activity marked by widespread plutonic and high-level granite-porphyry, which is favorable to the formation of porphyry copper (-gold) deposits and other related deposits. By referring to the experiences in assessment of porphyry copper deposits at home and abroad in recent years, this paper looks forward to the prospects of porphyry copper deposits in Tibet.
    46  Transition of the Late Mesozoic–Cenozoic tectonic regimes and modification of the Ordos basin
    ZHANG Yue-qiao ,  LIAO Chang-zhen
    2006, 33(1):28-40. DOI: 10.12029/gc20060103
    [Abstract](4652) [HTML](0) [PDF 1.63 M](6097) [Cited by](14)
    Abstract:
    Abstract：The Ordos basin is a large Mesozoic intracontinental basin superimposed on the Paleozoic North China craton. The Late Mesozoic-Cenozoic were an important modification period of the basin, during which significant changes in tectonic regimes occurred and tectonic belts of different trends and styles were formed around the basin. The main phase of the Yanshanian movement that took place during the Mid-Late Jurassic is of great significance for the shaping and development of the Ordos basin. Compressive tectonic belts surrounding the Ordos basin were mostly formed during this Yanshanian phase. During the Early Cretaceous, in response to the tectonic stress regime transition, the Ordos basin was subjected to week extension, and extensional deformation was localized along its SW margin, resulting in the development of the Liupanshan paleo-graben. During the Cenozoic, tectonic deformation mainly occurred around the Ordos basin, resulting in the formation of the grabens. During the Neotectonic movement since the late Miocene or early Pliocene, owing to the influence of the rapid uplift of the Qinghai-Tibet Plateau and its eastward extrusion, the Liupanshan fold belt on the southwestern margin of the Ordos rose rapidly, while extensional deformation and differential uplift and subsidence of the blocks took place in other peripheral zones of the basin. Finally, the paper discusses the basin modification in different tectonic stress regimes and some basic tectonic problems in the study of the Ordos basin.
    47  The assessment of geothermal resources potential of China
    LIN Wen-jing ,  LIU Zhi-ming ,  WANG Wan-li ,  WANG Gui-ling
    2013, 40(1):312-321.
    [Abstract](5778) [HTML](0) [PDF 2.47 M](9363) [Cited by](14)
    Abstract:
    Abstract：Based on expounding the characteristics of geothermal resources in China and taking into account the existence of different types of geothermal resources in China, the authors adopted different calculation methods to conduct the potential assessment of shallow geothermal resources, conductive geothermal resources, convective geothermal resources and hot dry rock resources. The results show that the shallow geothermal resources of key cities are 2.78×1020 J with the annual approved yield being 2.89×1012 kWh, the conductive geothermal resources of main planes (basins) reach 2.5×1022 J with the approved yield being 7.5×1021 J, the discharge energy of hot springs is 1.32×1017 J in total with the annual approved yield being 6.6×1017 J, and the hot dry rock resources of China in the depth 3.0-5.0 km come to 2.5×1025 J in total, and this amount is 2.6×105 times that the annual total consumption of energy resources at present.
    48  Granitoids and continental crustal growth modes in China
    XIAO Qing-hui ,  QIU Rui-zhao ,  DENG Jin-fu ,  LI Ting-dong ,  MO Xuan-xue ,  HONG Da-wei ,  WANG Tao ,  LU Xin-xiang ,  WU Fu-yuan， ,  XIE Cai-fu
    2005, 32(3):343-352. DOI: 10.12029/gc20050301
    [Abstract](3577) [HTML](0) [PDF 1.01 M](5161) [Cited by](13)
    Abstract:
    Abstract：Orogenic granitoids in the continent of China may fall into the east and west regions. The orogenic granitoids in the west region include the Central Asian orogenic belt, Qinling-Qilian-Kunlun orogenic belt and Gangdise orogenic belt in the Qinghai-Tibet Plateau, which are associated with the development of the ocean, and the orogenic granitoids in the east region, including Northeast China, North China and South China, are Yanshanian orogenic granitoids formed after the assembly of the continent of China. Based on the settings and geological and geochemical characteristics of granitoids of different orogenic belts (exemplified by orogenic granitoids in Altay, East Kunlun, Yanshan in North China, Northeast China and Nanling in South China), the relationships between granitoids and continental crustal growth are discussed, and five modes of continental crustal growth in the continent of China are proposed；they are as follows:(1)the Altay mode of continental growth is that the material and heat of the Paleozoic convertive mantle formed on the background of the Paleo-Asian Ocean were input into the Paleozoic continent and mixed with the materials of the upper crust；(2) the East Kunlun mode is that the basement of the Proterozoic orogenic belt was reworked by the heat input and materials of the Paleozoic-early Mesozoic convective mantle formed on the background of TTG continental crust of the Proterozoic orogenic belt；(3) the Northeast China style is that the Phanerozoic continental crust was reworked by the heat input and materials from the convective mantle formed on the background of the Yanshanian Central Asian orogenic belt；(4) the Yanshan mode is that the Archean basement was reworked by the heat input and materials from the Yanshanian convective mantle；and (5) the Nanling mode is that in South China what was input by the Yanshanian convective mantle into the continent was mainly heat and subordinately materials and the crustal material recycle was the dominant mode for the continental growth (showing zero continental growth). These modes are the basic modes for the Phanerozoic continental growth of the continent of China.
    49  Geological and geochemical characteristics of the Dayishan granitoids in southern Hunan and their relations to mineralization
    WU Guang-ying ,  PAN Zhong-fang，LI Jin-dong ,  XIAO Qing-hui，CHE Qin-jian , 
    2005, 32(3):434-442. DOI: 10.12029/gc20050312
    [Abstract](3210) [HTML](0) [PDF 1.01 M](4807) [Cited by](13)
    Abstract:
    Abstract： Hierarchical units of the Dayishan granite are determined through geological and geochemical survey and study of the rock body. The authors think that the Dayishan granite is a composite intrusion formed by three phases and multiple stages of Indosinian and Yanshanian magmatic activities. Mineralization is mainly related to Mid-Late Jurassic granitic magmatism. The authors give the following points of understanding of tin-polymetallic ore-bearing granite： (1) Granitic magma in the same super-unit evolved from acid to acid-alkaline (calcium-poor and alkali-rich) composition from early to late times, i.e. the later-stage acid-alkaline intrusions show more marked metallogenic specialization. (2) Plagioclase commonly has An=4 to 15, with albite predominating； biotite has Mf<1.20, belonging to siderophyllite-ferruginous biotite； the granite has high silica with SiO2＞73%, higher alkalis with Na2O＋K2O＞7.5% and K2O / Na2O＞1.20 and lower calcium with CaO＜0.80%, and the peralumina index AKNC>1.10, alkalinity AR>2.5 and differentiation index DI>50； the ratio of the number of oxygen atoms to the total number of molecules is >1.98 and is rich in F and B； LREE is enriched relative to HREE and the value of Eu depletion is <0.30. (3) The rock shows higher Sn, W, F, As, Sb, Pb, Zn, Cu and U anomalies and the placer minerals are cassiterite, wolframite, antimony minerals and cinnabar, as well as lead, zinc and copper minerals. (4) The Indosinian-Yanshanian NW-trending Chenzhou-Shaoyang fault is of sinistral compresso-shear origin in the early stage and shows tenso-shear, compounding and multiple transition features； the syntectonic granitic magma was emplaced sequentially in three phases obliquely along the NW-trending tectonic belt from southeast to northwest. Tin-polymetallic deposits (occurrences) are distributed around the intrusion. The deposit types mainly include the altered granite type, greisen dike type and fractured type. The metallogenic conditions and ore indications are also summarized and analyzed.
    50  The genesis of high arsenic groundwater: a case study in Datong basin
    WANG Yan-xin ,  SU Chun-li ,  XIE Xian-jun ,  XIE Zuo-ming
    2010, 37(3):771-780.
    [Abstract](2864) [HTML](0) [PDF 1.46 M](4481) [Cited by](12)
    Abstract:
    Abstract：Geogenic high arsenic groundwater occurs in Datong basin, northern China. This paper reports the results of recent studies of high arsenic groundwater in Datong, which include spatial distribution of high arsenic groundwater, hydrochemical evolution, source of arsenic, and geochemical processes controlling the mobilization of arsenic. Carboniferous-Permian coal-bearing clastic rocks around the basin may constitute the primary sources for arsenic in groundwater. Iron-bearing magnetic minerals are the main carrier of arsenic in the aquifer system and organic matter-enriched lacustrine sediments is the secondary source for arsenic in groundwater. In the central part of the basin, groundwater permeation is very slow and evaporation is the major way of groundwater discharge. Intensive evaporation results in the increase of TDS content. Decomposition or oxidation of organic carbon in aquifer sediments is catalyzed by bacteria and/or microorganisms, resulting in prevalence of anoxic conditions. Under high pH and low Eh conditions, due to the adsorption of arsenic by iron or/and manganese oxyhydroxides and the decrease of clay minerals, part of arsenic absorbed on the surface of these minerals tends to be released from sediments during this process. On the other hand, iron and manganese oxyhydroxides with strong adsorbing capacity for arsenic are reduced to low valence states which are soluble under low Eh conditions, so arsenic adsorbed on their surface is released to groundwater. Under anoxic conditions, dissolved SO2-4 and organic carbon can be reduced to produce H2S and CH4. Although dissolved arsenic can be removed from groundwater via the reaction with pyrite due to FeAsS precipitation, the low concentration of dissolved iron and sulfate in groundwater may limit this reaction. When sulfate is used up, methanogens will prevail the biogeochemical processes and further promote the enrichment of arsenic in groundwater. In addition, pH increase induces desorption of a wide variety of oxyanions, such as phosphate, vanadate, uranyl and molybdate, which tend to accumulate in the groundwater. Competitive adsorption of these oxyanions with arsenic can result in the release of arsenic from sediments into groundwater
    51  The second ore-prospecting space in the eastern and central parts of the Nanling metallogenic belt: evidence from isotopic chronology
    LIU Shan-bao ,  CHEN Yu-chuan ,  FAN Shi-xiang ,  XU Jian-xiang ,  QU Wen-jun ,  YING Li-juan
    2010, 37(4):1034-1049.
    [Abstract](2472) [HTML](0) [PDF 3.04 M](4105) [Cited by](12)
    Abstract:
    Abstract：A study of Re-Os isotopic chronology of molybdenite suggests that the metallogenic age of the Anqiantan tungsten ore deposit in south Jiangxi area within eastern Nanling region is about 156 Ma and that of the Yuanlingzhai molybdenum ore deposit is about 160Ma. Statistics indicate that there occurred 3 epochs comprising 6 stages of mineralization during Mesozoic in the eastern and central parts of the Nanling metallogenic belt. These stages are about 225 Ma and 195 Ma of Indo-Chinese period, 170-160 Ma, 160-150 Ma and 150-145Ma of Early Yanshanian period, and about 135 Ma and 100 Ma of Late Yanshanian period. The mineralization during Early Yanshanian period is the strongest one, so that Early Yanshanian is the major metallogenic period for tungsten and tin ore deposits in the eastern and central parts of the Nanling metallogenic belt. There exist independent W-Sn polymetallic ore deposits, Sn ore deposits, Cu-Pb-Zn polymetallic ore deposits and Mo ore deposits. Combined with an analysis of metallogenic chronology, the authors hold that there might exist undiscovered or neglected mineral resources in the horizontal direction as well as metallogenic potential at the depth of the known ore deposits in the vertical direction. This study has provided theoretic basis for geological prospecting in the second space of the eastern and central parts of the Nanling metallogenic belt.
    52  Characteristics of alkali feldspar granite in tungsten (tin) deposits of Nanling region
    ZHU Xin-you ,  WANG Jing-bin ,  ,  WANG Yan-li ,  CHENG Xi-yin ,  HE Peng ,  FU Qi-bin ,  LI Shun-ting
    2012, 39(2):359-381.
    [Abstract](3176) [HTML](0) [PDF 3.84 M](5293) [Cited by](12)
    Abstract:
    Abstract：The early Yanshanian granites related to tungsten and tin deposits in Nanling region have been considered to be biotite granite, monzogranite, albite granite etc. However, microscope and electron microprobe analyzes of the granite related to tungsten mineralization in Yaogangxian, Shizhuyuan, Xitian, Dengfuxian, Limu and Meiziwo show that all the feldspars of the granite consist of K-feldspar and albite (An<5), which suggests that the name should be alkali feldspar granite. The albite of greisen inclusions in the alkali feldspar shows the character An<3. There is no obvious vertical regular variation or zoning of the compositions of the albite and granite within the depth range of 1000m. On the contrary, the plagioclases of the granite inclusions (xenoliths), some granite porphyry dykes, giant batholiths, and Triassic and Paleozoic monzogranite or granodiorite have a wide range of An value of 0～93, belonging to oligoclase, andesine or even basic plagioclase. The alkali-feldspar granite that contains two kinds of alkali feldspar was usually formed from the rich-volatile (Li-F) magma, with the extensive development of liquid immiscibility at the top of the granite, which caused the enrichment and mineralization of W, Sn, Bi, Mo in the hydrothermal-magma. The An value of the albite in alkali-feldspar granite could be used as an indicator for evaluating granite in search for W-Sn mineralization, because the value is obvious lower than that of barren granite.
    53  Metallogeny of iron deposits and resource potential of major iron minerogenetic units in China
    LI Hou-min ,  WANG Deng-hong ,  LI Li-xing ,  CHEN Jing ,  YANG Xiu-qing ,  LIU Ming-jun
    2012, 39(3):559-580.
    [Abstract](4246) [HTML](0) [PDF 9.00 M](6749) [Cited by](12)
    Abstract:
    Abstract：Iron resource is an important metal resource in China. Summary of iron metallogeny and analysis of iron resource potential are of theoretical and practical significance. This paper summarizes the natural endowment characteristics of the iron resource in China. Iron deposits in China are classified into metamorphosed sedimentary-type iron deposits, magmatic-type iron deposits, contact metasomatic-hydrothermal-type iron deposits, volcanogenic type iron deposits, sedimentary type iron deposits and weathering-infiltration type iron deposits as well as 40 typical iron deposit styles. Metallogenic models of Anshan type, Damiao type, Mengku type and Daxigou type iron deposits are established. This paper divides China’s iron resource into 36 iron minerogenic units, and also summarizes the temporal and spatial distribution of iron deposits of different genetic types, different deposit sizes, and different ore types. The resource potential of 7 important minerogenetic units is also discussed.
    54  The broken line in the figure denotes the boundary of the Asian continent before collision Mushroom structure of the lithospheric mantle and its genesis at depth: revisited
    YUAN Xue-cheng
    2007, 34(5):737-758.
    [Abstract](2611) [HTML](0) [PDF 8.84 M](4614) [Cited by](11)
    Abstract:
    Abstract：Analysis of geophysical data shows that there is no evidence for subduction of the Pacific plate beneath the continent of present eastern China except the Jilin-Liaoning (Jiliao) area, Northeast China. The tremendous change that has taken place in eastern China since the Mesozoic did not result from the subduction of the Pacific plate beneath continental China but is a major geological event caused by the reworking of the lithospheric mantle by mushroom structure formed by upwelling of asthenospheric materidals. The upwelling of asthenospheric materials resulted in the formation of a structure of coexistence of the new mantle and remnant mantle, reactivation of the lithosphere, folding of the crust of stable cratons, crustal thinning, repeated occurrence of earthquakes, active magmatism, ground subsidence and formation of vast marginal seas of the western Pacific. However, the thickness of the lithosphere did not decrease, and only the rate of lithospheric thinning decreased owing to the formation of the mushroom structure of the mantle. As a result, the lithospheric structure in the region is notably different from those in its surrounding regions. The region with the mushroom-shaped mantle covers the western Pacific region of the whole of Southeast Asia, including the east-central part of Northeast China, eastern North China, the southeastern margin of South China, Malaysia Peninsula, Indonesia, the Philippine, the Sea of Japan, Yellow Sea, East China Sea, South China Sea, the Caroline basin and the Philippine sea basin. There also exists a huge geodesic ellipsoidal positive anomaly corresponding to the low-velocity lithospheric mantle in the western Pacific region of Southeast Asia, which should be caused by mass surplus at the core-mantle boundary. It and its twin—the negative geodesic ellipsoidal anomaly caused by mass deficiency at the core-mantle boundary in the Indian Ocean-Tibet region—form a deep-level dynamic system controlling the structures of continental China. The age of this dynamic system might be Mesozoic or Late Paleozoic. The mantle circulation between brought about a tremendous change of the lithosphere below the western Pacific of Southeast Asia and drove the northward migration of the Indian plate and uplift of the Qinghai-Tibet Plateau.
    55  High-resolution sequence stratigraphic correlation of fan deltas and distribution characteristics of sandbodies
    JIN Song ,  ZHU Xiao-min ,  ZHONG Da-kang
    2006, 33(1):212-220. DOI: 10.12029/gc20060124
    [Abstract](2500) [HTML](0) [PDF 1.10 M](4257) [Cited by](11)
    Abstract:
    Abstract：According to the core and well log data and lithologic and electric correlation, high-resolution sequence stratigraphic study has been conducted on the fan deltaic reservoirs in pay sets 4 to 8 of the Third Member of the Shahejie Formation in the Huzhuangji oilfield. The criteria for recognition of different orders of cycle boundaries and cycle types are established, and the studied section is divided into one long-term cycle and six medium-term cycles. The correlation principle and method of short-term stratigraphic cycles are determined and the framework of correlation of short-term cycles is established according to the controls of medium-term cycles on the deposition of sandbodies and relationship between the geomorphological change and types of short-term cycles parallel or perpendicular to the direction of the provenance. The distribution characteristics of sandbodies and reservoir properties in short-term cyclic sequences are notably different in different phases of a medium-term base-level cycle, which is the main cause responsible for serious reservoir interlayers or plane heterogeneities. It should be taken into account when the sequences of strata which are to be exploited are distinguished in detail.
    56  Metallogenic conditions of in-situ leachable sandstone-type uranium deposits and dynamic evolution of the Turpan-Hami basin
    WU Bo-lin ,  XU Gao-zhong ,  LI Wei-hong ,  GONG Bing-li ,  ZHANG Fu-xin
    2004, 31(1):101-107. DOI: 10.12029/gc20040116
    [Abstract](2630) [HTML](0) [PDF 594.33 K](3973) [Cited by](11)
    Abstract:
    Abstract： Analyses of the climate, geomorphologic features, groundwater dynamics, tectonics and structure, development conditions of interlayer oxidation zones and geological and geochemical characteristics of the ore target beds suggest that the metallogenic conditions of in-situ leachable sandstone-type uranium deposits in the north of the Turpan-Hami basin are notably different from those in the south (the slope zone of Aydingkol Lake, Liaonang depression and Nangfu depression). The basic cause is related to the difference in dynamic evolution in the southern and northern parts of the basin. According to the characteristics of tectonic subsidence, tectonic sequences and influence by plate motion, the tectonic evolution of the basin can be divided into five stages, of which the third stage (Carboniferous to Triassic), the compression-type foreland basin sedimentary stage, laid the foundation of the differences in tectonic evolution between the south and north of the basin, and had profound influence on the distribution of Meso-Cenozoic in-situ leachable sandstone-type uranium deposits, the fourth stage (Jurassic to Cretaceous), the weak extensional-type downfaulted basin stage, provided the material foundation for the formation of uranium deposits in the south of the basin, and the fifth stage (Paleogene to Quaternary), the Cenozoic compressional-type foreland basin stage, provided the sufficient exterior dynamic force for the formation and enrichment of the uranium deposits in the south of the basin.
    57  Basic results of multi-target geochemical survey in the Nanjing area and its relevant problems
    LIAO Qi-lin ,  Wu Xin-min ,  WENG Zhi-hua ,  ZHU Bai-wan ,  PAN Yong-min ,  CHEN Bao ,  JIN Yang
    2004, 31(1):70-77. DOI: 10.12029/gc20040111
    [Abstract](2737) [HTML](0) [PDF 843.46 K](6735) [Cited by](11)
    Abstract:
    Abstract：The Nanjing area is a typical representative of the very thick Quaternary cover areas in the Yangtze River delta. This paper reports some basic results obtained since multi-target geochemical survey has been carried out in the area. Through experiments, some key technical criteria and requirements have been worked out and generalized. The authors think that it is feasible to take samples from topsoil at a depth of 0 to 20 cm and deep soil at a depth of ≤150 cm respectively, use the –20 mesh fraction of soil and adopt sampling densities of one sample per square kilometer for topsoil and one sample per 4 square kilometers for deep soil. Two belts polluted by some heavy metallic elements exist in topsoil in the Nanjing areas, and marked enrichment of heavy metallic elements in topsoil has direct influence on the safety of crops and vegetables in the study area. At last, the authors discuss a number of questions as to how to determine the geochemical background values in studied soils, how to examine and appraise environmental geochemical anomalies and how to treat the relationship between the total content of some elements and their effective concentrations in topsoil and so on, and propose relevant suggestions.
    58  Geological characteristics and ore prospects of underground leaching sandstone-type uranium deposits on the southwestern margin of the Turpan-Hami basin
    ZHOU Qiao-sheng ,  LI Zhan-you
    2003, 30(2):186-191. DOI: 10.12029/gc20030212
    [Abstract](4869) [HTML](0) [PDF 745.20 K](6406) [Cited by](11)
    Abstract:
    Abstract：Through an integrated study of the data of uranium prospecting and exploration of the Shihongtan area in recent years, the paper systematically deals with the conditions of uranium deposit formation, such as the geological structure, depositional environment of ore-bearing rock series, distribution of sand bodies and development features of interlayer oxidation zones and also intensively studies the zoning of the ore-controlling interlayer oxidation zone, shapes, sizes and spatial distribution of orebodies, mode of occurrence of uranium, mineralization age and regularity of uranium mineralization. It further summarizes the regional formation conditions and ore prospects of sandstone-type uranium deposits. With progression of uranium prospecting, the southwestern margin of the Turpan-Hami basin is expected to become a large base of underground leaching sandstone-type uranium resources. This study has great significance for guiding prospecting for underground leaching sandstone-type uranium deposits in the Tianshan orogenic belt and similar areas.
    59  New advances in the geological study of the Qinling orogen
    Yang Zhi-hua ,  GUO Jun-feng ,  SU Sheng-rui ,  LI Yong ,  SU Shun-qian ,  Zhang Chuan-lin ,  HEI Ai-zhi ,  LIANG Yun
    2002(3):246-256. DOI: 10.12029/gc20020303
    [Abstract](2758) [HTML](0) [PDF 2.27 M](5665) [Cited by](10)
    Abstract:
    Abstract: During the Eighth and Ninth Five-Year Plan periods, major developments were made in geological studies of the Qinling-Bashan region: (1) creation of the new theory of choula (drawing) thrust sheet tectonics, which enriched and developed the diversity of the movement modes of the lithospheric plates or crustal blocks; (2) discoveries of N-S-trending uplift zones and sedimentary basins in the E-W-trending Qinling orogen, especially the discovery of the Taibai uplift zone and Baoji-Foping- Hannan uplift zone, which will bring about a radical change of our understanding of the tectonic framework of the Qinling Mountains and even east-central China; (3) recognition of two new types of orogen for the supracrustal layers, type-Ⅱ and type- Ⅲ, the former being E-W-trending orogens transformed from N-S-trending sedimentary basins and the latter being those formed by drawing-out and thrusting of deep tectonic sheets over Meso-Cenozoic continental sedimentary basins; (4) recognition of the existence of three types of sedimentary basins, three kinds of basin-range transformation, three development stages and three types (Ⅰ, Ⅱ and Ⅲ) of orogen; (5) reassessment of the tectonic natures and ages of the Shangdan, Mianlue and Erlangping tectonic belts and first proposition of the new view that the development of the Qinling orogen was controlled by three tectonic systems and went through four evolution stages and that the intracontinental orogen formed by drawing-out tectonism was the most important development stage; (6) first presentation of overpass structure; (7) discovery of some pre-Sinian metamorphic crystalline series and reassessment of the ages of some strata, especially the discovery of the Mesoproterozoic strata in the Xicheng lead-zinc ore field in the West Qinling, in which the superlarge Changba deposit is hosted; (8) presentation of the new concept of para-turbiditic fluid; and (9) advancement of a new geodynamic hypothesis concerning the tectonic evolution of the Qinling orogen and the continent of China.
    60  Global geochemical mapping
    XIE Xue-jing
    2003, 30(1):1-9. DOI: 10.12029/gc20030101
    [Abstract](3299) [HTML](0) [PDF 1.08 M](3947) [Cited by](10)
    Abstract:
    Abstract：The deficiencies in more than 50 national and regional geochemical mapping projects in the world carried out from 1973 to present are all analytical in character. The IGCP259 Project under the aegis of UNESCO＇s IGCP Program carried out from 1988 to 1992 aimed to standardize geochemical mapping methods used in the world. This project advances several analytical requirements for forthcoming geochemical mapping projects, which mainly include the following: 71 elements should be analyzed in the future mapping projects; the detection limits of trace and ultratrace elements must be lower than the corresponding crustal abundances and the Chinese GSD and Canadian STSD standard sample series should be used for the correlation of global data; the aim of the IGCP360 Project (Global Geochemical Mapping Project) is to use 5000 composite samples taken at very low sampling densities to cover the whole Earth＇s land surface. Besides social，political and economic problems, the main bottleneck is the difficulties to meet IGCP259 analytical requirements by many countries. The best way to solve this bottleneck is proposed in the present paper.
    61  Sequence stratigraphy and sedimentary system of the Paleogene Shahejie Formation in the Raoyang subbasin
    NI Chao ,  JI You-liang
    2006, 33(1):193-200. DOI: 10.12029/gc20060122
    [Abstract](2619) [HTML](0) [PDF 1.01 M](4624) [Cited by](10)
    Abstract:
    Abstract：The sequence stratigraphy and sedimentary system of the Paleogene Shahejie Formation of the Raoyang subbasin have been studied by employing seismic, well log and drilling core data. On the basis of the identification and correlation of sequence stratigraphic units, the Shahejie Formation has been divided into six third-order sequences and 14 system tracts. The paper analyzes the main cause of formation of each sequence in detail and sums up different characteristics of various sequences. In addition, the sedimentary characteristics and sedimentary systems in each sequence are analyzed and the controlling effects of sequence development on the sedimentary systems are pointed out. During the study, the authors also studied the types of oil-gas reservoirs and characteristics of oil-gas accumulation in different system tracts of a sequence, and on that basis, they indicate the most favorable oil-gas reservoir types possibly developed in various system tracts.
    62  Geochemical characteristics and zircon U-Pb ages of island-arc basic igneous complexes in the Tianshui area, West Qinling
    PEI Xian-zhi，LI Zuo-chen，DING Sa-ping ,  ，LＩ Yong， HU Bo， LIU Hui-bin
    2005, 32(4):529-540. DOI: 10.12029/gc20050401
    [Abstract](2896) [HTML](0) [PDF 1.18 M](3956) [Cited by](9)
    Abstract:
    Abstract：The Liushuigou intermediate-basic meta-igneous complex at Guanzizhen, Tianshui, is composed mainly of metagabbro-metagabbro diorite-metadiorite, and the Baihua basic meta-igneous complex consists mainly of pyroxenite-gabbro (-diorite)-diorite-quartz diorite. They form a relatively complete comagmatic evolutionary series. The geochemical characteristics of basic to intermediate-basic igneous rocks indicate that they belong to a tholeiite suite. Their chondrite-normalized REE patterns are of nearly flat and slightly LREE-enriched type, and their primitive mantle-normalized and MORB-normalized trace element spidergrams are generally similar; the LILEs Cs, Ba, Sr, Th and U are enriched, while Rb and K and the HFSEs Nb, P, Zr, Sm, Ti and Y are depleted. All these show comagmatic evolutionary and genetic characteristics. The tectonic environment discrimination by trace elements reveals that these igneous complexes formed in an island-arc setting. The TIMS single-zircon U-Pb age for the Liushuigou intermediate-basic meta-igneous rocks in the Guanzizhen area is 507.5±3.0 Ma, representing the age of these igneous complexes, which indicates that island-arc-type magmatic rocks in the north zone of the West Qinling are Late Cambrian in age and also reveals that the timing of subduction of the paleo-ocean basin represented by the Guanzizhen ophiolite and resulting island-arc-type magmatic activity is probably Late Cambrian to Early Ordovician.
    63  3D lithospheric structure of western China and its enlightenment on petroleum prospecting
    YUAN Xue-cheng
    2005, 32(1):1-12. DOI: 10.12029/gc20050101
    [Abstract](3198) [HTML](0) [PDF 1.21 M](5695) [Cited by](9)
    Abstract:
    Abstrac：The 3D lithospheric structure of western China studied by using satellite gravity anomalies revealed that in the crust of western China there exist regular, distinct, parallel, linear basin-range structures. From north to south, there are: the Ertix basin belt, North Junggar uplift belt, North Tianshan basin belt, Tianshan uplift belt, Naomaohu -Olji basin belt, South Tianshan basin belt, Kuruktag- Beishan uplift belt, Altyn Tagh（Altun）-North Qilian belt (or South Tarim basin belt) and West Kunlun-Altyn Tagh-Qilian uplift belt, as well as the Qaidam basin belt and southern Tibet basin belt. These crustal basin belts formed by strong basal compression folding in the Indosinian-Yanshanian period. In the Himalayan period, northeast-directed subduction of the Indian plate resulted in uplift of the Borohoro-Qapqal -Ala Gou-Erben-Horo mountains, and they together with the Tianshan Mountains divide Xinjiang into the Tarim basin, Junggar basin, Tuha basin and Yining basin, forming the present-day geomorphology of Xinjiang. These NW-SE mountains and other NW-SE neotectonics have their corresponding satellite gravity anomalies in the lid of the lithosphere. Thus it is inferred that the dynamic force of the neotectonic movement was derived from the lithospheric mantle. In Tibet, the idea that the Tibetan Plateau is regarded as the superficial structure formed by a number of parallel faults such as the Yalung Zangbo fault, Bangong Co-Nujiang fault, Lanchang River fault and Jinsha River fault and the elongated blocks sandwiched therein does not conform to the crustal structure at ~15 to 18 km depth. This kind of elongated block structure and the southeast-directed escape structure only occur in the upper crust. Study also indicates that subduction of the Indian plate to the mantle only occurs in southwestern Tibet. In western Sichuan-eastern Tibet there exits a stable block which interrupts subduction of Indian plate beneath Tibet. The study provides the following enlightenment on petroleum prospecting: (1) petroleum prospecting in western China should not be restricted in Cenozoic basins; (2) in the study of the tectonic setting of basins in western China one should consider the structural control at depths; and (3) basic research may play an important role in petroleum prospecting and furnish clues leading to finding Paleozoic and Mesozoic oil/gas fields, and the research results may be used for reference in work arrangement, and especially we should carry out a systematic investigation and study of the whole deep aspects of the North Tianshan basin belt, South Tianshan basin belt, South Tarim basin belt, Qaidam basin belt and North Tibet basin belt and their control on the surface structures.
    64  Minerogenetic series of metallic ore deposits in the Qinling Mountains and tectonodynamic background of the continental orogenic belts
    WANG Jing-hua ,  ZHANG Fu-xin ,  YU Zai-ping ,  YU Lan
    2002(2):192-196. DOI: 10.12029/gc20020216
    [Abstract](2869) [HTML](0) [PDF 157.26 K](5201) [Cited by](9)
    Abstract:
    Abstract: On the basis of the tectonic units, tectonic evolution and deposit association, the Qinling orogenic belt is divided into four mineralization concentration areas: the Xiao Qinling craton activation area, Xiong'ershan rift accretion area, South Qinling passive continental-margin down- faulted area and Bikou terrane paleo-assemblage zone, which separately form four minerogenetic series: the granite-greenstone belt-type gold-iron minerogenetic series, continental volcanic-hosted gold-molybdenum minerogenetic series, sedimentary-hosted gold-lead-zinc-mercury -antimony minerogenetic series and marine volcanic-hosted gold-silver polymetallic and ultrabasic-hosted nickel-gold minerogenetic series. Syngenetic mineralization is related to extensive mantle or hot spot activities in the early stage (Paleozoic and its preceding stage) of format of the orogenic belt; post-genetic mineralization was accomplished during the basin-range transformation and intracontinental tectono-magmatic activities (at 120 -340mA).
    65  Geological characteristics of the formation of the large Tahe oilfield in the Tarim basin and its prospects
    KANG Yu-zhu
    2003, 30(3):315-319. DOI: 10.12029/gc20030315
    [Abstract](3623) [HTML](0) [PDF 486.39 K](5438) [Cited by](9)
    Abstract:
    Abstract：The Tahe oilfield in the northern part of the Tarim basin is China’s first largest Paleozoic oilfield. It was discovered from 1990 to 1997. By 2002 a petroleum-bearing area of ~ 1000 km2 was controlled, with explored reserves of 250 million tons. Its discovery has great significance for guiding the search for this type of oilfield in the Tarim basin and even the whole of China. The author thinks that sediments in the Tarim oilfield are depression-type marine carbonate rocks in the ancient cratonic basin. It is located in a cratonic paleo-uplift-Shaya uplift, where faults and regional unconformities are very well developed, which are favorable for the concentration of oil and gas. As it adjoins the Manjiar oil-generating depression on the south, it is a good vector area for oil and gas migration. Two Hercynian tectonic movements resulted in the development of Ordovician paleokarst, thus giving rise to reservoirs with good pores, caves and fissures. Moreover, the occurrence of four phases of oil and gas migration and accumulation is the basic condition for the formation of a large oil/gas field. This oilfield is expected to become an exceedingly large oilfield with oil reserves of 800 million to 1 billion tons.
    66  High magnesian andesitic/dioritic rocks (HMA) and magnesian andesitic/dioritic rocks (MA)： two igneous rock types related to oceanic subduction
    DENG Jin-fu ,  LIU Cui ,  FENG Yan-fang ,  XIAO Qing-hui ,  SU Shang-guo ,  ZHAO Guo-chun ,  KONG Wei-qiong ,  CAO Wen-yan
    2010, 37(4):1112-1118.
    [Abstract](3068) [HTML](0) [PDF 636.72 K](6461) [Cited by](9)
    Abstract:
    Abstract：This paper discusses two igneous rock types (HMA and MA) related to oceanic subduction based on a brief review of the experimental petrological data. On such a basis, some suggestions are put forward as follows： (1) The utilization of both the MgO % and FeO/MgO (% ratio) at given SiO2 as the diagnostic parameters is emphasized in recognition of HMA and MAl. (2) On the basis of the LF-CA (Low-Fe calc-alkaline) characteristics, HMA and MA may be distinguished from each other by using the SiO2%-MgO % parameter system. (3) Either of the two methods, i.e., the diagram approach (Fig.2&3) or the numeric approach (Table 1,2&3), may be used for the nomenclature of HMA and MA.
    67  The implication of six kinds of new sandstone-type uranium deposits to uranium resources potential in North China
    ZHANG Jin-dai ,  XU Gao-zhong ,  LIN Jin-rong ,  PENG Yun-biao ,  WANG Guo
    2010, 37(5):1434-1449.
    [Abstract](2431) [HTML](0) [PDF 5.44 M](4101) [Cited by](9)
    Abstract:
    Abstract：Through ten years’ effort, six kinds of new large and superlarge sandstone-type uranium deposits have been found and explored in Mesozoic-Cenozoic sedimentary basins within North China, which are named temporarily as Yili pattern, Turpan-Harmi pattern, Dongsheng pattern, Ulanchap pattern, Manite pattern and Tongliao pattern. They occur in sedimentary basins of different tectonic settings and are different in deposit geology, ore body geology and controlling factors., but they have some common basic characteristics in metallogenic evolution. In Yili pattern and Turpan-Harmi pattern, mineralization is of typical interlayer redox feature; nevertheless, the former pattern is characterized by uranium superimposition and enrichment under the condition of whole uplift of monocline or different uplifting and falling conditions of ore-bearring strata, whereas the latter pattern is characterized by mineralized zonation on the southern and northern sides of the fault superimposed on the structural slope and small anticline structure under tectonic uplifting. In Dongsheng pattern, mineralizaton is mostly dominated by paleo-interlayer oxidation zone modified by later reduction; in Ulanchap pattern, mineralization is closely related to the evolution of lake flooding events; In Manite pattern, mineralization is of paleovalley type formed by alternation between phreatic redox and interlayer redox; in Tongliao pattern, mineralization is controlled by “tectonic window, fault and reducing matters in the deep part”, and is also probably related to dikes of basic rock (heat source). In the above six patterns , a rule may occur in their rock assemblage from west to east. The west three pattern are controlled by Upper and Middle Jurassic coal-bearing clastic rocks, while the east three patterns are controlled by Lower Cretaceous argillaceous sandstone and fine sandstone. It is indicated that the discovery and exploration of the six new kinds of sandstone-type uranium deposits not only strengthen insurable capability of uranium resources in China but also indicate the orientation and deploy for uranium resources potential evaluation and prospecting in the future.
    68  Tectonic attribute of the Qoltag orogenic belt in the East Tianshan Mountains, northwestern China
    CHEN Fu-wen ,  HE Guo-qi ,  LI Hua-qin
    2003, 30(4):361-366. DOI: 10.12029/gc20030405
    [Abstract](2810) [HTML](0) [PDF 769.36 K](3839) [Cited by](8)
    Abstract:
    Abstract：The Joltag orogenic belt is located between the Turpan-Hami basin and Central Tianshan block, in the East Tianshan Mountains. For a long time different views exist as to the tectonic attribute of this orogenic belt, e.g. it is considered as a Late Paleozoic arc island belt, a backarc basin, an aulacogen, a Paleozoic continental-marginal accretion belt or Carboniferous volcanic-type passive continental margins. Based on systematic petrological, petrochemical and rock geochemical studies of the volcanic-sedimentary formations of the Early Carboniferous Yamasu Formation in the belt and the fact that the Qoltag area was in an intraplate extensional dynamic setting rather than a noncompresional collisional dynamic setting during the Early Paleozoic，the authors conclude that the Qoltag orogenic belt should be an extensional tectono-magmatic one.
    69  Geological characteristics and genesis of rock body-type tin deposits in the Dayishan ore field
    Liu Tie sheng
    2002(4):411-415. DOI: 10.12029/gc20020415
    [Abstract](2541) [HTML](0) [PDF 139.74 K](4869) [Cited by](8)
    Abstract:
    Abstract: Rock body-type tin deposits in Dayishan, Hunan, occur in the Late Jurassic Jietou unit of the Tangshipu super-unit. The ore is slightly below the medium grade and easy to dress. The deposits are large in size and formed in a restricted environment, showing vertical zoning. Regional structures, magmatic rocks, country rocks and restricted environment jointly control the occurrence and size of the rock body-type tin deposits. In this paper the genesis of the rock body-type tin deposits is analyzed. As the magma is differentiated and evolved in a restricted environment, ore-forming elements are unevenly distributed, causing the intrusion of the Jietou unit to be rich in W and Sn and an ideal metallogenic model of rock body-type tin deposits is formed in the front or uparching portion of the intrusion. From above downward the rock body-type tin deposits show the characteristics of vertical zoning of alteration and mineralization from high to low temperatures.
    70  Multi-target geochemical survey and results of double-layer sampling in Chengdu City
    ZHAO Qi
    2002(2):186-191. DOI: 10.12029/gc20020215
    [Abstract](2588) [HTML](0) [PDF 172.13 K](4652) [Cited by](8)
    Abstract:
    Abstract: Through multi-target geochemical survey advances have been made in the study of the background values ??and distribution characteristics of the elements, study of structure, agriculture and environmental pollution, prediction of natural gas and calculation of the pH values. It is judged that the deep-layer samples play a special role in the study of the distribution of deep-seated elements, structure, development of root-deep crops and prediction of natural gas and that the shallow-layer samples plays a special role in the study of the distribution of shallow-seated elements, agricultural geology and environmental pollution. The multi-target geochemical survey and double-layer sampling can be popularized.
    71  Exploration and study of Carlin and Carlin-like type gold deposits：review and prospect
    ZHANG Fu-xin ,  XIAO Li ,  QI Ya-lin
    2004, 31(4):407-412. DOI: 10.12029/gc20040411
    [Abstract](3277) [HTML](0) [PDF 976.60 K](6108) [Cited by](8)
    Abstract:
    Abstract：The superlarge Carlin gold depost and a metollogenic belt extending over one thousand kilometers were discovered in the western region of the Unitid States in the 1960s. This aroused the attention of various countries in the world. The theory on Carlin type gold prospecting was introduced into China in the 1970s, and after the prospecting practice and preliminary study, the clues leading to finding Carlin type gold deposits were found in Shaanxi and Guizhou, China. A major breakthrough in gold exploration was made in China in the middle and late 1980s, and more than 40 large and intermediate Carlin-and Carlin-like type gold deposits have been delineated in the “nothwest gold triangle” and “southwest gold triangle” at the nothwest and southwest margins of the Yangtze block. Major advances have been made in the study of typical deposits. Mineral exploration reached a higher level in China in the 1990s. In addition to the discovery of a number of deposits, some superlarge gold deposits of this type were successfully found and an integrated study of the ore deposit genesis, metallogenic mechanism, deposit types and metallogenic dynamics was conducted. In the new century, gold deposits have still been found unceasingly. This shows the great potential and good prospects in looking for Carlin- and Carlin-like type gold deposits in northwestern and southwestern regions of China.
    72  Artificial environmental concentration coefficients of elements in soils in the Nanjing area
    LIAO Qi-lin ,  JIN Yang ,  Wu Xin-min ,  Bi Kui-sen ,  Fan Di-fu ,  Hua Ming
    2005, 32(1):141-147. DOI: 10.12029/gc20050119
    [Abstract](3241) [HTML](0) [PDF 718.39 K](4302) [Cited by](8)
    Abstract:
    Abstract：Data of contents of relevant elements from“double-layer”soils have been obtained during multi-target geochemical survey in Nanjing and its surrounding areas. The ratio of the content of an element in topsoils (depth 10-20 cm) to its content in deep soils (depth 150-200 cm) is called artificial environmental concentration coefficient in soils. This paper mainly introduces the calculating methods of the artificial environmental concentration coefficients. According to the distribution characteristics of the concentration coefficients of various elements in the study area, it is found that in topsoils of the area the contents of elements such as Si, Ti, La, Ce, Y, Sc, Zr, Th , U and W are close to their contents in the natural soil environment and elements such as S, N, P, Hg, Pb, Cl, Br and Se, as well as Corg show pronounced artificial environmental concentrations, while elements such as I, Fe, Mg, Mn, Ca, Al and K are depleted in the topsoils. Finally, problems relating to an intensive study of the artificial environmental concentration coefficients of elements in topsoils are discussed and some helpful suggestions are put forward.
    73  Early Mesozoic granites and polymetallic mineralization in southeastern Yichun area, Xiao Hinggan Mountains
    HAN Zhen-zhe ,  ,  ZHAO Hai-ling ,  LI Juan-Juan ,  LENG Cheng-en ,  LU Jun ,  ,  LI Wen-long
    2010, 37(1):74-87.
    [Abstract](2087) [HTML](0) [PDF 4.92 M](5357) [Cited by](8)
    Abstract:
    Abstract：The Late Triassic-Early Jurassic monzonitic granite in southern Yichun area of the Xiao Hinggan Mountains extensively has migmatitic MME-type fine-grained dark dioritic enclaves and plutonic intermediate-basic mafic dikes, characterized by crust-mantle mixture. In contrast, the syenitic-alkali feldspar granite is characterized by aluminian A2 type granite. Their petrographic, major and minor element and isotopic features show that their formation was related to underplating in an extension-collapse environment of the transition period from continental collision to post-collision after the closure of the palaeo-Asia Ocean. The similarity of the two types of granites in genesis, material source and metallogenic background also finds expression in their similarity of metallogenic series. The monzonitic granite assumes the Mo-Pb-Zn-Fe-Au-Ag metallogenic series, with Mo and Pb ore-forming processes being most intense, whereas syenitic- alkali feldspar assumes the Zn-Pb-Cu-Mo-W-Fe metallogenic series, characterized by weak and scattered mineralization. Their certain degrees of difference in metallogenic series might have to do with the somewhat different degrees of crust-mantle mixture. The difference of these Mesozoic granites in ore-forming features, ore deposit types, mineralization intensities and mineralization types indicates that this area still has great potential in search for polymetallic ore deposits.
    74  The strategic consideration of the development of China's airborne geophysical technology
    XIONG Sheng-qing
    2009, 36(6):1366-1374.
    [Abstract](2784) [HTML](0) [PDF 4.13 M](4158) [Cited by](8)
    Abstract:
    Abstract：This paper has described the current development and application of China's airborne geophysical technologies (airborne magnetic survey, EM, gravity, and radiometric technology) and dealt with some practical progresses in such fields as the airborne geophysical instrument, survey technology, data processing and interpretation, and professional software. Nine main problems and the development trend of China's airborne technology are also analyzed. It is held that future development of airborne geophysics will be focused on high resolution and deep detection technology. Some suggestions have been put forward, which include the development of multiple-parameter aero magnetic survey, airborne gravimeter and gradiometer, deep detection TEM, the sensor of high temperature superconductor, some inversion and 3D visual technologies, the establishment of geophysical laboratories, the perfection of airborne geophysical test bases and dynamic test sites, and the acceleration of the technology standardization.
    75  Zircon SHRIMP U-Pb dating of the tuffaceous bed of Xiajiang Group in Guizhou Province and its stratigraphic implication
    GAO Lin-zhi ,  DAI Chun-gu ,  LIU Yan-xue ,  WANG Min ,  WANG Xue-hua ,  CHEN Jian-shu ,  DING Xiao-zhong
    2010, 37(4):1071-1080.
    [Abstract](3003) [HTML](0) [PDF 3.61 M](4215) [Cited by](8)
    Abstract:
    Abstract：Some zircon dating data of the tuffaceous bed are reported for the first time from the Sibao and Xiajia groups in Guanxi and Guizhou. In combination with the SHRIMP U-Pb dating of the granite that intruded into the Sibao Group, the Xiajia Group is determined to be of Late Neoproterozoic. These isotopic data are very important for us to redefine the age of the Sibao Group and to conduct regional correlation of strata in the corresponding period and tectonic evolution. The Sibao Group (the same as the Fanjingshan, Lengjiaxi and Shuangqiaoshan groups) and the Danzhou Group (the same as the Xiajiang, Banxi and Heshangzheng groups), which are subsequent metamorphosed rocks well developed in the Jiangnan Orogen, formed a metamorphosed basement of the Jiangnan Continent. In the past, the Sibao Group, which constituted the main part of the Sibao Movement, was designed to Mesoproterozoic, and the determined age still affects the stratigraphic subdivision and correlation of the metamorphosed rocks in whole Jiangnan Continent and restricts the determination of the geological background and metallogenic conditions of the Jiangnan Orogen. Based on studying zircon from bentonite in the Sibao Group and overlying strata, the authors accurately dated the zircon at (814.0±6.3) Ma in the Jialu Formation, and (773.6±7.9) Ma in the Qingshuijiang Formation. The series of zircon dating data have solved the problem of the Neoproterozoic ages and also provided a new marker for the Jiangnan Orogen.
    76  Tectonic-sedimentary landform classification of 1∶250000 Changde Sheet and its implication for researches on Quaternary geology and environment of Jianghan-Dongting basin
    BAI Dao-yuan ,  LI Song-wen ,  ZHOU Ke-jun ,  MA Tie-qiu ,  WANG Xian-hui ,  PENG Yun-yi ,  LI Gang
    2010, 37(2):280-297.
    [Abstract](2382) [HTML](0) [PDF 2.31 M](4128) [Cited by](7)
    Abstract:
    Abstract：The 1∶250000 Changde Sheet strides across Wuling uplift and Jianghan-Dongting basin from west to east, characterized by complicated Quaternary uplift-depression tectonic framework. Based on detailed geological mapping and lots of borehole data, the authors conducted tectonic-sedimentary landform classification and mapping of this sheet according to Quaternary tectonic activity, sedimentation and present elevation and topographic characteristics. Types of tectonic-sedimentary landforms were derived from decomposition of traditional landform types based on Quaternary geological process. Ten types of tectonic-sedimentary landforms were defined, namely, rising-denudation middle-low mountain (Ⅰ), uplift-denudation hilly area (Ⅱ), sedimentary and later uplift-denudation hilly area (Ⅲ), sedimentary and later uplift-denudation hilly plateau (Ⅳ), eluvial-slope wash hilly plateau (Ⅴ), isolated hill (Ⅵ), subsiding-sedimentary and later uplift-denudation hilly plateau (Ⅶ), subsiding-sedimentary and later uplift wave plateau (Ⅷ), stable sedimentary low plateau (Ⅸ) and subsiding-sedimentary low plateau (Ⅹ). A detailed analysis shows that every type of tectonic-sedimentary landform possesses its unique characteristics of elevation, Quaternary uplifting-falling activity, weathering-erosion and sedimentation. Tectonic-sedimentary landform classification and geomorphologic map not only show geographic environments but also provide effective means for direct and visual expression of Quaternary strata, tectonic features and geological-environmental evolution. In addition, these means will promote and deepen researches on Quaternary geology and environment of the Jianghan-Dongting basin.
    77  Re-Os isotope dating of the Da'ao tungsten-tin deposit in the Jiuyi Mountains, southern Hunan Province
    FU Jian-ming ,  LI Hua-qin ,  QU Wen-jun ,  YANG Xiao-jun ,  WEI Jun-qi ,  LIU Guo-qing ,  MA Li-yan
    2007, 34(4):651-656.
    [Abstract](3115) [HTML](0) [PDF 722.99 K](4453) [Cited by](7)
    Abstract:
    Abstract：The Da'ao tungsten-tin deposit in the Jiuyi Mountains, southern Hunan, is closely related to the Jinjiling composite granite which has the characteristics of aluminous A-type granite. The deposit types include the greisen type, altered granite type, fractured zone alteration type and greisen-quartz vein type. Based on the precise Re-Os dating of molybdenite from the ore-bearing greisen-quartz vein, a mineralization age of 151.3±2.4 Ma was obtained, which is consistent with the formation age (151-156 Ma) of granite, suggesting that the mineralization occurred simultaneously with the rock formation. An integrated analysis and comparison of highly precise mineralization ages obtained on a regional scale shows that the period of 150-160 Ma was the peak stage of Mesozoic large-scale mineralization in the Nanling region and that the Da'ao tungsten-tin deposit in the Jiuyi Mountains is just the product of this peak stage. The new data provide important isotope chronological evidence for the further study of the regional metallogenic characteristics and guidance of regional mineral prospecting.
    78  Mesozoic asthenospheric upwelling orogeny in eastern China
    XIAO Qing-hui ,  QIU Ruizhao ,  WU Guang-ying ,  XING Zuo-yun，ZHANG Yu ,  TONG Jin-song
    2006, 33(4):730-750. DOI: 10.12029/gc20060404
    [Abstract](2743) [HTML](0) [PDF 2.62 M](4056) [Cited by](7)
    Abstract:
    Abstract: Mesozoic orogens in eastern China are different from continental-margin subductional and continent-continent collisional orogens and are not the product in a particular stage of development and evolution of continental-margin and continent-continent collisional orogens either. They are a new type of orogen resulting from orogeny due to asthenospheric upwelling at depth and may be distinguished from plate-margin and continent-continent collisional orogens by their tectonic setting, tectonic framework, tectonic deformation and metamorphism, magmatism and sedimentation and tectonic evolution. We consider that such orogeny caused by asthenospheric upwelling is another orogenic mechanism that is as important as continent-continent collisional and plate-margin subductional orogenies. Therefore the process of formation of orogens by asthenospheric upwelling is termed by us asthenospheric upwelling orogeny or East Asia-type orogeny. Viewing the Da Hinggan orogen, Yanshan orogen and other orogens in eastern China from the lithospheric-asthenospheric deep process, we think that the formation of these orogens is an orogenic event caused by vertically upward dynamic processes originating by asthenospheric upwelling at depth as well as a new orogenic mechanism. The evidence is as follows: (1) the lithosphere-asthenosphere dos not show a typical horizontal layered structure but asthenospheric material commonly occurs as mushroom-shaped upwelling plumes penetrating and intruding into the lithospheric mantle, thus causing the older lithospheric mantle to be extensively dismembered and delaminated and forming a steep contact pattern with the relics of the older mantle; (2) the chronological structure of the lithosphere has the nature of uncoupling, i.e.: the mantle is younger, while the crust is older; (3) mafic-ultramafic rocks generated by underplating and ascending of Mesozoic asthenospheric material along lithospheric fractures are found; (4) magmatism of Mesozoic volcanic-plutonic rocks is different from that of classic subduction-type and continent-continent collision-type magmatic rocks but is related to upwelling of the asthenosphere; and (5) the process of asthenospheric upwelling orogeny has the unique character of evolution from the deep level to shallow level. Asthenospheric upwelling orogeny in eastern China is a global important tectonothermal event and its orogenic process is as follows: (1) before and in the initial orogenic phase in the Early Mesozoic (230-180 Ma), upwelling and underplating of asthenospheric material at depth resulted in linear fracturing and local delamination of the cold and strong continental lithosphere; (2) in the main orogenic phase in the Mid-Late Jurassic (180-140 Ma), due to large-scale upwelling of asthenospheric material and its lateral intrusion and extension along the crust～mantle boundary at the base of the lithosphere, vertical differential movement was transformed into horizontal compression, and thus extensive fold and nappe structures occurred at the crustal surface, causing the continental crust to be thickened into the crustal root and the lithospheric root to be delaminated; and (3) in the late orogenic phase in the Cretaceous (140-80 Ma), with thickening of the continental crustal root and extensive delamination of the lithospheric root, the lithosphere entered a completely new stage of transition from compression to extension and substantial thinning and the asthenosphere upwelled to form mountains.
    79  Composition of the Mianlue suture zone and its relation with the evolution of the old oceanic basin
    LI Ya-lin ,  LI San-zhong ,  ZHANG Guo-wei
    2002(2):129-134. DOI: 10.12029/gc20020204
    [Abstract](2804) [HTML](0) [PDF 178.74 K](5024) [Cited by](7)
    Abstract:
    Abstract: The Mianlue suture zone is a typical ophiolitic-tectonic mélange belt. All the rocks have undergone strong deformation and metamorphism; so the composition of the belt is complex. The dominant tectonic style is marked by an imbricate structure characterized by overlapping of different thrust sheets with a series of north-dipping thrust faults as the framework. Study of its detailed composition and structure suggests that the suture zone is composed of continental-margin sedimentary sequences of different natures formed in different stages of formation and evolution of the oceanic basin, different types of ophiolite and tectonic blocks exposed in different modes during the subduction -collisional orogeny of the oceanic basin. Besides, regional stratigraphic correlation indicates that the formation of the Mianlue oceanic basin is characterized by east-directed "scissors-type" opening and propagation.
    80  New geochronological data of granites and ores from the Nannihu-Sandaozhuang Mo(W) deposit
    XIANG Jun-feng ,  MAO Jing-wen ,  PEI Rong-fu ,  YE Hui-shou ,  WANG Chun-yi ,  TIAN Zhi-heng ,  WANG Hao-lin
    2012, 39(2):458-473.
    [Abstract](3753) [HTML](0) [PDF 7.47 M](4732) [Cited by](7)
    Abstract:
    Abstract：The Nannihu-Sandaozhuang molybdenum deposit is the largest porphyry-skarn type deposit in eastern Qinling region. This paper reports new LA-ICP-MS zircon U-Pb age data of granitoids (including granitic veins) and ICP-MS molybdenite Re-Os isotopic age data of the samples from the mining area. The obtained formation ages of granitoids are 145.2±1.5 ~ 146.7±1.2Ma, and the model ages of 5 molybdenite samples from stockwork in the Nannihu mining area and 5 molybdenite samples from disseminated skarn in the Sandaozhuang mining area are 143.4±2.0 ~ 146.5±2.3Ma with isochron age of 146.0±1.1Ma. These new geochronological data show explicitly that the granitoids and ores were formed simultaneously, suggesting their genetic relationship. Furthermore, these new data have confirmed the existence of magma-thermal event at about 158Ma revealed by previous dating work, and also for the first time revealed that the eastern Qinling area once underwent another magma-thermal event at about 175Ma. The published weighted average age data are of distinct deviation from the real intrusive age of the Nannihu magmatic body, which results from 1) nonhomogeneous origin of zircons in magmatic rock and 2) unrepresentative dating of zircon group.
    81  The metallogenic system of porphyry-skarn type Cu ,Mo(Au) polymetallic deposits in Geza island arc of Yunnan Province
    LIU Xue-long ,  LI Wen-chang ,  YIN Guang-hou
    2012, 39(4):1007-1022.
    [Abstract](2428) [HTML](0) [PDF 5.87 M](5018) [Cited by](7)
    Abstract:
    Abstract：Geza island arc belt is one of the important tectonic units in the archipelagic arc-basin system of the Sanjiang Region. it started its evolution at the westward subduction of Ganzi-Litang oceanic crust in Late Triassic, and experienced intracontinental convergence and post-orogenic extensional phase in Yanshanian period. In this region, there were strong magmatic activities and rich mineralization, constituting an important copper polymetallic ore concentration area discovered in recent years. According to temporal and spatial distribution of magmatic rocks and ore deposits, geochronological evidence, tectonic setting and mineralization, the Geza island arc metallogenic system can be divided into Indosinian metallogenic subsystem and Yanshanian metallogenic subsystem. The Indosinian subsystem mainly developed intermediate-acidic crust-mantle magmatism homologous with the andesite and formed porphyry Cu metallogenic system; the Yanshanian subsystem had syn-collision magmatic activities leading to the generation of the porphyry Mo (Cu) and W (Mo) hydrothermal metallogenic system. Studies show that Geza island arc has favorable resource potential in the depth, with Mo polymetallic mineralization of Yanshanian epoch showing better prospect.
    82  Development and construction of the 1:500000 geological map database
    ZHANG Qing-he ,  CAO Bang-gong ,  JIANG Lan
    2002(2):208-212. DOI: 10.12029/gc20020219
    [Abstract](3336) [HTML](0) [PDF 89.70 K](4248) [Cited by](6)
    Abstract:
    Abstract: The 1:500000 geological map database of China was developed with the China-made software MAPGIS 5.0 as the basic platform and the appended maps (1:500000) of regional geology of all the provinces, autonomous regions and municipalities and the 1:200000 geological map of the Hong Kong Special Administrative Region as the basic data. The geological map was compiled by using new theories and ideas on modern geology, stratigraphy and petrology and new methods of presentation and according to the lithostratigraphic units, hierarchical units of granites and time plus lithology for intrusive rocks. The database was composed of the digital geological map database and geographic base map database. The retrieval can be made arbitrarily according to any space scope, different scales, different projection methods and different geological and geographic content, and one can retrieve one item or multiple items. Through retrieval a complete geological map with the legend and ornaments is produced automatically.
    83  Apatite fission-track records of the tectonic uplift of the central segment fo the Kunlun Mountains on the northern margin of the Qinghai-Tibet Plateau
    BAI Dao-yuan ,  MENG De-bao ,  LIU Yao-rong ,  MA Tie-qiu
    2003, 30(3):240-246. DOI: 10.12029/gc20030303
    [Abstract](2672) [HTML](0) [PDF 751.30 K](5037) [Cited by](6)
    Abstract:
    Abstract： Three groups of apatite fission-track ages indicate three tectonic uplift events： the uplift of the Altyn Tagh block at the end of the Cretaceous (69.5±2.9 Ma BP) and the uplifts of the front of the Kunlun Mountains and rear zone of the Kunlun Mountains (on the northern margin of the plateau region) in the late Pliocene (4.2±0.8 Ma BP and 3.9±0.6 Ma BP) and in the middle Early Pleistocene (1.66±0.31 Ma BP). The paleo-altitudes of the apatite fission-track samples are calculated on the basis of the paleo-burial depths of the samples and paleo-altitudes of the surface inferred according previous relevant data, and then the absolute tectonic uplift amount is calculated, which is equivalent to the altitude difference and the absolute rate of tectonic uplift is equivalent to the ratio of the absolute uplift amount to the difference of apatite fission-track ages. The results of the calculation are as follows：the northern margin of the Altyn Tagh has risen 4 940 m since 69 Ma BP, with an average uplift rate of 0.072 mm/a; the front zone of the Kunlun Mountains has risen 1 380 m from 4.15 to 1.66 Ma BP, with an average uplift rate of 0.55mm/a, and risen 4 140 m since 1.66 Ma BP, with an average uplift rate of 2.49 mm/a; the rear zone of the Kunlun Mountains has risen 1 500 m from 3.85 to 1.66 Ma BP, with an average uplift rate of 0.70 mm/a, and it has risen 5 140 m since 1.66 Ma BP, with an average uplift rate of 3.19 mm/a. In combination with the relevant terrace features and ages, it may be estimated that the average uplift rate of the rear zone of the Kunlun Mountains may have reached 11 mm/a since the end of the late Pleistocene (21 ka BP). The rear zone of the Kunlun Mountains may have risen 1 120 m relative to the front zone of the Kunlun Mountains since 4 Ma BP and the ratio of the average uplift rates of the two zones is about 1.2.
    84  Carboniferous to Permian sequence stratigraphic framework of the Yunnan-Guizhou-Guangxi basin and its adjacent areas and global correlation of third-order sea-level change
    MEI Ming-xiang，MA Yong-sheng，DENG Jun，CHU Han-min，LIU Zhi-rong，ZHANG Hai
    2005, 32(1):13-24. DOI: 10.12029/gc20050102
    [Abstract](3546) [HTML](0) [PDF 1.16 M](5384) [Cited by](6)
    Abstract:
    Abstract：The Yunnan-Guizhou-Guangxi basin is a passive continental-margin rift basin. After the Caledonian movement，it began to be pulled apart in the Devonian and continued to develop in the whole of the Late Paleozoic. Controlled by the contemporaneous faults，isolated carbonate platforms of varying size developed in the deep-water basin. Thus a special paleogeographic framework of "platform-basin-hill-trough" formed in the Yunnan-Guizhou-Guangxi basin and its adjacent areas. On the basis of the division into third-order sequences in different paleogeographic settings and their tracing and correlation in space，12 third-order sequences may be distinguished in the Carboniferous and Permian strata in the basin and its adjacent areas. They are equivalent to SQ14 to SQ25 of 25 Late Paleozoic third-order depositional sequences (SQ1 to SQ25，2～5 Ma). On the basis of two kinds of facies-change surface and two kinds of diachronism in stratigraphic records，a Carboniferous to Permian sequence stratigraphic framework may be established in the study region，which reflects the basic features of third-order sequences：ordering of facies sequences in space and synchroneity of environmental changes in time. The Carboniferous and Permian in the study region consist predominantly of a suite of carbonate rocks. In this suite of strata，three coal measures are developed in the land-connected platforms，and two suites of sponge reefs are developed on the margins of the land-connected platforms and in the isolated platforms，which make up sequence stratigraphy in Carboniferous and Permian successions that is greatly different from that in Europe and America.
    85  Analysis of high-resolution sequence stratigraphy of the Upper Jurassic Penglaizhen Formation in the Baimamiao gas field, Qionglai County, Western Sichuan
    ZHAO Yong-gang ,  CHEN Jing-shan ,  LEI Bian-jun ,  JIANG Yu-qiang ,  WANG Shen-jian ,  XU Dan-zhou
    2005, 32(4):674-681. DOI: 10.12029/gc20050417
    [Abstract](2709) [HTML](0) [PDF 914.11 K](4031) [Cited by](6)
    Abstract:
    Abstract：Under the guidance of the theory and techniques of high-resolution sequence stratigraphy, through a comprehensive analysis of the outcrops, rock cores, well logs and seismic data, 3 sequence boundaries of different genetic types and growth scaleｓ and 3 orders of lacustrine flooding surfaces are recognized in the Upper Jurassic Penglaizhen Formation in ｔｈｅ Baimamiao gas field, and in addition, 2 long-term base-level cycles, 6 middle-term base-level cycles and 38-40 short-term base-level cycles are distinguished and their characteristics are discussed in detail. The thin-bedded limestone and calcareous shale close to the top of the middle-term base-level cycle can be regarded as one of the important indicator for recognizing the middle-term base-level cycle. On the basis of the above, using the method of cycle isochronostratigraphic correlation, different orders of base-level cycles are correlated and 3 isochronostratigraphic stratigraphic frameworks with different time-scales are established. The high-resolution sequence stratigraphic analysis has great significance for further exploration and development of the gas accumulations in the Penglaizhen Formation of the Baimamiao gas field.
    86  Features of organic reefs in the Upper Permian Changxing Formation and prediction of hidden reefs in the Huanglongchang structure, Eastern Sichuan
    LI Denghua ,  TANG Yue ,  YIN LI Jun ,  XIE Fen Jifeng
    2006, 33(2):427-435. DOI: 10.12029/gc20060222
    [Abstract](2472) [HTML](0) [PDF 1.27 M](3865) [Cited by](6)
    Abstract:
    Abstract:Study of four well cores and relevant data of other wells obtained from the Upper Permian Changxing Formation in the Huanglongchang structure has demonstrated that there are organic reefs in cores from the Huanglong No. 1 well and Huanglong No. 4 well but no reefs in cores from the Huanglong No. 3 well and Huanglong No. 5 well. The reefs consist of sponge bafflestones, wh ICH belong to carbonate platform margin reefs. Due to little difference in physical properties of reef and strata strong heterogeneity Nonreef, in reefs and outstanding multiple solutions to the prediction problem, the authors used the prediction method of combining geological, logging and seismic approaches to determine the boundary of the organic reef gas reservoir in the Huanglong No.1 well area and found an organic reef gas reservoir on the western side of the Huanglong No. 5 well. Thus a practical method for predicting reefs is provided.
    87  A new pattern of tectonic units of China considered in light of the lithosphere
    QIU Rui-zhao ,  ，LI Ting-dong ,  ，DENG Jin-fu，ZHOU Su，Xiao Qing-hui，ZHAO Guo-chun ,  LIAN Chang-yun，LIU Da-wen
    2006, 33(2):401-410. DOI: 10.12029/gc20060219
    [Abstract](2241) [HTML](0) [PDF 1.22 M](4072) [Cited by](6)
    Abstract:
    Abstract：This paper proposes a new pattern of tectonic units of China based on the petrological structure model of the lithosphere under continental China and five types of lithosphere, namely, cratonic lithosphere, orogenic lithosphere, rift lithosphere, marginal-sea oceanic crust lithosphere and island arc lithosphere,distinguished according to the dynamic properties of the lithosphere, combined with the present characteristics of compression in the west and extension in the east of continental China. The content of the new pattern is as follows：the lithospheric discontinuity along the western boundaries of the Sichuan,Ordos and Yinchuan basins is used as the boundary to divide continental China into two first-order tectonic units, i.e. the western China tectonic unit and the eastern China tectonic unit;the above-mentioned different types of lithosphere are considered as their second-order tectonic units; and some subtypes of the orogen-type lithosphere are the third-order tectonic units. On the basis of the new pattern of tectonic units, combined with the geological history, their formation processes and implications for ore finding are also discussed briefly in this paper.
    88  Geochemical characteristics and tectonic setting of the early Yanshanian South Zhuguangshan granite in the central segment of the Nanling Mountains
    MA Tie-qiu ,  KUANG Jun ,  BAI Dao-yuan ,  WANG Xian-hui
    2006, 33(1):119-131. DOI: 10.12029/gc20060113
    [Abstract](2785) [HTML](0) [PDF 1.37 M](4142) [Cited by](6)
    Abstract:
    Abstract： The South Zhuguangshan pluton is a composite granite batholith formed in the Caledonian, Indosinian and early Yanshanian periods. This paper mainly discusses early Yanshanian granites, namely, the Middle Jurassic Sanjiangkou sequence. The sequence is composed of five rock-units, and the rock type is hornblende-biotite monzogranite-biotite monzogranite-two-mica monzogranite. The earlier units contain abundant mafic micro-enclaves, and the petrographic study of the enclaves indicates the crust-mantle mixing origin of the granitic magma. The average content of SiO2 increases from 68.95% in the early-formed granite units to 76.3% in the late-formed granite units. The rocks are alkali-rich. Their Na2O+K2O ranges from 7.11％ to 8.24%, with an average of 7.73% and K2O＞Na2O, and their ASI values range from 0.92 to 1.19, with an average of 1.05；so they belong to the magnesian-ferruginous, metaluminous-peraluminous, high-K calc-alkaline series. The rocks are of light REE-enriched type, with a moderate ΣREE content of 213μg/g and strong Eu depletion, and have negative anomalies of Ba, Nb, Sr, P, Ti, Eu and Ba and positive anomalies of Rb, U, Th, Nd, Zr, Sm and Y, which indicate an intracontinental tectonomagmatic environment. The rocks have ISr values of 0.7115 to 0.72466, εNd (t) values of －10.0 to －12.6 with an average of －10.97 and t2DM ages of 1.75 to 2.0 Ga with an average of 1.84 Ga. The average age is close to that (1.7 to 1.8 Ga) of Mesozoic granites in the Nanling Mountains, indicating that the rock-forming materials were mainly derived from the Mesoproterozoic crust. The tectonic setting discrimination diagrams based on multiple oxides and trace elements suggest that granites of the Sanjiangkou sequence formed in a post-orogenic extensional environment during the transition from compressional orogeny to non-orogeny. The authors consider that the early Yanshanian tectonic setting in the Nanling Mountains and even South China is post-orogenic rather than an intracontinental rift.
    89  Comparison of the sedimentary characteristics of the Donghe sandstone section between the Tabei and Tazhong areas, Tarim basin
    ZHU Xiao-min ,  ZHANG Qiang ,  LV Xue-yan ,  SUN Chao
    2005, 32(4):648-654. DOI: 10.12029/gc20050414
    [Abstract](2294) [HTML](0) [PDF 761.57 K](4052) [Cited by](6)
    Abstract:
    Abstract：The Donghe sandstone is a marine petroleum-bearing reservoir that was first found in China. An integrated study of the geological and geophysical data of the Tarim basin show that the Donghe sandstone in Tabei and Taｚｈong has high compositional and textural maturities, typical grain-size parameters of the marine environment and trace element association and distinct littoral-neritic sedimentary structures. However, there are differences in details of sedimentary characteristics and sedimentary environment in the Donghe sandstone. The Donghe sandstone in the Tabei area was deposited in the littoral and barrier island－lagoonal environment, while the sandstone in the Tazhong area in the estuary－littoral environment. Finally, this paper elucidates the vertical sequence ｏｆ the sedimentary characteristics and distribution of sedimentary facies of the Donghe sandstone ｓｅｃｔｉｏｎ in the Tabei and Tazhong areas.
    90  Characteristics and dynamic cause mechanism of the Wenchuan Earthquake geological hazards
    QIAO Yan-xiao ,  MA Zhong-she ,  LV Feng-jun
    2009, 36(3):736-741.
    [Abstract](2226) [HTML](0) [PDF 2.55 M](4858) [Cited by](6)
    Abstract:
    Abstract：Geological hazards of the Wenchuan Great Earthquake are characterized by a wide affecting range and a high density. The main types of the geological hazards are collapse and landslide, the collapse occurs far more frequently than the landslide, and the secondary geological hazards are likely to be existent for a long period in future. These characteristics are caused mainly by the spread of the seismic waves from the inside of the earth's crust to the surface as well as the spread of the P wave after S wave, which results in the harm to the mountain's inside structure, followed by the loss of the stability of the surface rock. The differences between lithology, landform and rock inclination exert to a certain extent influence on the geological type and the spatial distribution. In the post-earthquake reconstruction, the arduousness of the task and the protracted nature of the geological hazard control should be taken fully into account.
    91  A preliminary study of the relationship between granitoids and the growth of continental crust: a case study of the formation of key orogen granitoids in China
    XIAO Qing-hui ,  DENG Jin-fu ,  QIU Rui-zhao ,  LIU Yong ,  FENG Yan-fang
    2009, 36(3):594-622.
    [Abstract](2572) [HTML](0) [PDF 6.21 M](6160) [Cited by](6)
    Abstract:
    Abstract：Based on the achievements concerning the formation of granitoids in the East Kunlun orogenic belt, Qinling orogenic belt, Xingmeng orogenic belt, Altay orogenic belt, Yanshan orogenic belt and South China peraluminous granitoids, this paper has dealt with the formation of key orogenic zone granitoids in mainland China and the continental crust growth and reached some preliminary conclusions: the input of the asthenosphere（mantle convection）thermal materials to the mainland made up the foundation of the growth and reworking of the earth's crust. The formation, evolution and reworking of the continental crust mainly underwent magmatism, whose formation, migration and positioning made up the basic process of continental crust growth. Mantle-derived basaltic magma underplating on the bottom of the continental crust and intraplating within the crust constituted the basic form of the input of the asthenosphere to the mainland. Delamination of mafic orogenic belt in the lower crust was the key mechanism, which made the continental crust composition chemically intermediate (andesite and diorite, or trachyte andesite and monzonitic rock). The contraction extrusion tectonism thickened the continental crust to ≥50 km, which was the necessary prerequisite for inducing delamination of the mafic lower crust. The igneous tectonic assemblage and its time series seem to be the key to identifying the separation of the continental crust from the mantle asthenosphere until the eventual formation
    92  Geology and geochemistry of the Xiajiadian gold deposit in the Cambrian black rock series in the South Qinling
    GAO Ju-sheng ,  WANG Rui-ting ,  ZHANG Fu-xin ,  QI Ya-lin ,  LIANG Xiao-yong
    2006, 33(6):1371-1378.
    [Abstract](3003) [HTML](0) [PDF 1006.38 K](5184) [Cited by](6)
    Abstract:
    Abstract：Study of the Xiajiadian gold deposit, South Qinling, has led to the following understanding: microdisseminated gold deposits are hosted in gold-rich barite-chert hydrothermal sedimentary rock series, and the formation of the ore deposits has gone through synsedimentary preconcentration and a process of industrial concentration from brittle-ductile shear structural overprinting to post-hydrothermal reworking. The gold mineralization has close coupling relations to the tectonic evolution of continental subduction-collisional orogeny in the area. The ore-forming processes of this gold deposit may fall into three epochs and eight stages. The ores are composed of three types and eleven subtypes, showing complex ore-forming processes. The homogenization temperatures of fluid inclusions in ore minerals cluster at the range of 199-300℃ and the mineralization pressures range from 370×105 to 820×105 Pa, showing the features of meso- and epithermal mineralization. The salinities of the fluid inclusions were 3.27 wt.% NaClequiv. in the early mineralizing stage and 5.25 wt.% NaClequiv. in the middle and late stages. The hydrogen and oxygen isotopic compositions of the ore minerals form six samples are δ18OH O=-7.86‰ to +0.37‰ and δDH O=-80.70‰ to -66.30‰. The data points in the plot shift laterally from meteoric water to the right, suggesting that the ore fluids consisting predominantly of meteoric water have been subjected to intense reworking. The Xiajiadian gold deposit is a microdisseminated (Carlin-like type) gold deposit. The mineralization has the features of hydrothermal deposition-brittle-ductile structural overprinting-reworking of hydrothermal ore fluids dominated by meteoric water.
    93  Paleo-karstification types, karstification periods and superimposition relationship of Ordovician carbonates in northern Tarim Basin
    NI Xin-feng ,  ZHANG Li-juan ,  SHEN An-jiang ,  PANG Wen-qing ,  QIAO Zhan-feng
    2009, 36(6):1312-1321.
    [Abstract](2209) [HTML](0) [PDF 2.96 M](4214) [Cited by](6)
    Abstract:
    Abstract：Karstification is one of the most important elements for the formation of Ordovician marine carbonate reservoirs in northern Tarim Basin. Based on lithology, geophysical data and test data, the authors divided karstification of northern Tarim Basin into three types (penecontemporaneous karstification, buried karstification, weathering karstification) and some subtypes. The penecontemporaneous karstification controls the formation and distribution of the early carbonate rock reservoirs, the buried karstification is always developed along the former pore-fracture systems, and constitutes one of the most key factors for reservoir optimization, and the weathering karstification is the key factor for the formation of Ordovician carbonate reservoirs. As for the characteristics of polycyclic structure evolution of northern Tarim Basin, there exist six periods of paleo-karstification in different superimposing and rebuilding stages and various Ordovician carbonate rocks, of which the most important periods for reservoir karstification are the early Caledonian II episode, the middle Caledonian I and II episode, and the early Hercynian. Different types of karstification in northern Tarim Basin have complex and pronounced superimposition relationship： the penecontemporaneous karstification provided basic pathway for the buried karstification； the subsequent buried karstification and weathering karstification were developed on the basis of succeeding to and superimposing on the former penecontemporaneous karstification and finally became the excellent potential reservoir.
    94  The formation and evolution of the Mesozoic-Cenozoic continental tectonics in eastern China
    GE Xiao-hong ,  LIU Jun-lai ,  REN Shou-mai ,  YUAN Si-hua
    2014, 41(1):19-38.
    [Abstract](5275) [HTML](0) [PDF 1.56 M](14835) [Cited by](6)
    Abstract:
    Abstract:In the Wilson cycle proposed in the 1960s, the collision of tectonic plates which leads to closure of oceanic basins on both sides of plates marks the end of the cycle. In interpreting continental tectonics in the past 20 years, it seems that the above conclusion is not comprehensive. Diffusive and widely distributed intracontinental deformation suggests that the action of platecollision has not ceased. After the formation of the Paleo- Asian continent, tectonic deformation, magmatism and cratonic basin formation widely developed during Mesozoic-Cenozoic period in eastern China were possibly related to the progressive opening of the Indian Ocean and the Arctic Ocean as well as the subduction of the Western Pacific and Philippine oceanic plates. This paper intends to discuss the major tectonic events, structural properties, the formation background and the temporal and spatial distribution of Mesozoic-Cenozoic tectonics in eastern China. From Late Hercynian to Indosinian period, the Paleo-Asian continent was formed due to amalgamation of various tectonic blocks during the closure of the Paleo-Tethys. During Late Jurassic - Early Cretaceous, accompanied by the closure of the Mongo-Okhotsk ocean, the continent-continent collision gave rise to the formation of the Paleo-Asian continent. Thrust-nappe structures were formed during the intracontinental deformation. At the same time, the Western Pacific Isanagi plate was subducted obliquely, which caused superimposation effect from east to west. In the Middle- Late Cretaceous-Paleogene period, together with the transition from thickened crust to lithospheric thinning and transformation, the intracontinental extensional deformation approached its peak stage. Continental craton basins peneplanes were formed. From Late Eocene to early Miocene (40-23 Ma), the superposition of the motion of the Pacific plate turning in NWW direction, the spreading of the middle oceanic ridges of the Indian Ocean, and the continent-continent collision between the Indian-Australian and the southern part of the paleo-Asian plate induced the formation of the new tectonic landforms in eastern China. Affected by East Asia-Western Pacific riftand the Indian Ocean ridge spreading during Middle Pliocene and early Pleistocene, the eastern China continent experienced lithospheric mantle uplift, crustal thinning, marginal and intracontinental extensional deformation. These processes resulted in the successive formation of marginal seas, island arc, rift basins and eroded highland landscapes. During Early Pleistocene (0.9-0.8 Ma) - Late Pleistocene (0.01 Ma) period, the tectonic landforms of Eastern China were finally formed.
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