Abstract:Abstract：China actually needs more shale oil/gas resources because the demand for fossil energy is expanding at present and its shortage tendency sweeps the whole world. Therefore, unconventional oil/gas resources, especially the exploration, development and utilization of shale oil/gas resources have been put on the agenda of social progress and economic development, and have been highly emphasized by many countries in the world. Consequently, shale oil/gas has now become a hot topic in China’s energy and technology fields and government departments. After a period of hot-hype and assessment without sufficient grounds, the authors put forward some points of view on the basis of an analysis and discussion of data available both in China and abroad, i.e. we should (1) comprehend the modes of occurrence and development conditions of shale oil/gas countries all over the world, especially in North America, and then understand independently the distribution state and potential in China based on adequate evidence; (2) understand the attributes and prospects of shale gas, the background of survey and storage in China, and more comprehensively carry out geophysical exploration of shale and shale gas as well as choose good promising typical areas for demonstration research, acquisition and exploration; (3) redefine the exploitation process, condition and environmental pollution degree of shale gas and key questions queried by many countries in the development of shale gas; (4) formulate comprehensively the development scheme and development route-map of shale gas in China from the viewpoint of concepts, practices and understanding; (5) not invest vigorously and implement eagerly exploitation and development of shale gas at present because the prospect is not optimistic.

Abstract:Abstract：Different mineral deposits have different characteristic features, just like the fact that different people have different finger prints. Based on the Chinese philosophic idea “white horse is a horse but not a horse (class)”, this paper proposes a deepening study of the integrated geological characteristics of the same types or similar groups of mineral deposits model with universality. On such a basis, the mineral deposits model with universality (horse class) will contain the kind of deposits with speciality (white horse) and increase its generality in correlation with unknown mineral deposits. Secondly, in this paper, the research work of mineral deposits model is systematically summarized and a new idea of metallogenic series is put forward for establishing the mineral deposits model with universality. Considering the existence of various mineral deposits in the geological setting, the authors integrate the geological tectonic settings, depositional environments and ore-hosting rock assemblages to formulate “a classification of mineral deposits model of China” and 74 models suitable for various depositional environments to be created (see table 1). On such a basis, we can find any deposits model from corresponding geological setting in the classification; in contrast, a certain mineral deposits model can also reflect the depositional environment in which the deposits occurred.

Abstract:Abstract：Four Precambrian block, i.e., Kuruk Tag-Tarim, Central Tianshan, Yili and Kepin, were recognized in Xinjiang on the southern margin of Central Asian orogenic belt. Studies show that (1) the Central Tianshan block has a close affinity with Tarim- Kuruk Tag block , as evidenced by similar pre-Nanhua basement, similar rock assemblages and tectono-magmatic evolutionary processes, implying that Kuruk Tag might be connected with Central Tianshan, and that the Kuruk Tag and Central Tianshan blocks were parts of the Tarim craton during Proterozoic period; (2) the Central Tianshan is a sub-block which was split from the northern Tarim craton during Neoproterozoic Nanhua period, and the Paleozoic Southern Tianshan oceanic basin was developed between the two blocks; (3) the Yili block was similar to the Tarim craton before Neoproterozoic Nanhua period in such aspects as rock assemblages, stratigraphic sequences, tectonic settings and evolution, showing some affinities for Tarim craton. After Nanhua period, geological differences between two blocks became obvious, and in Paleozoic, the Yili block might be linked with the Balkhash block, and in Silurian, two blocks amalgmated; (4) the Kepin block is an oceanic crustal terrane completely different from Kuruk Tag, Central Tianshan and Yili blocks in terms of rock assemblages, stratigraphic sequences, ages and evolutional history. Evidence from geological, magmatic and geochronological features and distribution of detrital zircon U-Pb ages show that Precambrian blocks (Kuruk Tag-Tarim, Central Tianshan, Yili and Kepin) of the northern Xinjiang region recorded abundant information of crustal deformation and magmatism during the early evolution of the Earth, suggesting a strong response to the global polyphase tectonic and magmatic events, including growth of the global continental core, assembly of the global Columbia, and assembly and breakup of the global Rodinia supercontinent. In contrast to the Kuruk Tag-Tarim, Central Tianshan and Yili blocks, the Kepin block preserved some records of the assembly event of Gondwana.

Abstract:Abstract：Based on the result of regional geological survey in China, this paper tries to generalize the theoretical system of China’s regional tectonics so as to outline its geodynamics and evolution in earth history. As we know, China is located at the juncture between the Circum-Pacific tectonic belt and the Tethys tectonic domain, with tectonic characteristics of a composite continent. Such a continent is composed of several geological blocks with distinct structures, biogeography fauna and evolution history. The blocks have been welded and amalgamated into the continent in the past 400 Ma years. Thus, China’s regional tectonics can make its due contribution to global tectonic theory in the following aspects：First, the tectonic blocks (or platforms) in China are small, non-rigid, with strong deformation of cover rocks in comparison with such other cratons as North American craton and African craton, and this phenomenon provides a window for studying continent growth and evolution. Second, the tectonic blocks of China’s composite continent were derived from different parts of the globe. Therefore, comprehensive research is necessary on large-scale paleomagnetism, paleontology-geography, paleo-sedimentation, paleo-tectonics, paleo-mineralization and paleo-environments, so as to understand the tectonic positions of China in global framework in different stages of its tectonic history. Such a study will surely contribute to the research on global tectonics. Third, China has many orogenic belts, in which the Tibetan Plateau and the Taiwan Coast Ranges are characterized by continental-continental collision and arc-continental collision in progress, respectively. The paleo/new-orogenic belts and their tectonic evolutions will enrich theories of global continental accretion. Fourth, geologists have long paid much attention to the retreat progress and path of Paleo-Tethys ocean from Paleo-Asian ocean, but without satisfactory result so far. The formation of Mesozoic-Cenozoic intra-continental deformation and basin-mountain tectonics-geomorphology in China is a hot topic which needs in-depth study in the light of continental dynamics. Sixth, the impact of geological processes on environmental change has also enlarged the area of regional tectonic studies.　　Facing development of science and technology in the new century, inter-discipline studies and new technology application will surely promote geological research. We are about to see the new flourishing prospect of China’s regional tectonic study.

Abstract:Abstract：Due to the convergence of multiple continental blocks and the development of many different types of sedimentary basins, Asian continent is an ideal place for studying the geological evolution of basins. This paper is focused on analysis of basin architecture, relationships between basin group and plate boundary, basin group and basement structure by drawing 4 long inter-continent profiles. Studies show that scales of sedimentary basins in Asian are generally small， the prototype basins have been poorly preserved, and the ages of basin basements are greatly different in contrast with other continents. Basins developed upon cratonic basement are relatively well preserved, while those overlying on the orogenic belt and oceanic crust basement have larger scale of subsidence, and are easily reworked. The changeable movement of plate tectonic boundary and smaller scale of landmass have resulted in a strong instability in the basin structure. The temporal and spatial superimposition between three big tectonic realms (Central Asia, Tethys, West Pacific), a series of cratonic blocks (Siberia, India, North China, Tarim, Yangtze, Indosinian etc. ) and mantle plume activities, have controlled the tectonic evolution of Asian basins, and caused obvious differences in their types and late preservation.

Abstract:Abstract：The Changle-Nan’ao zone is situated along the southeastern margin of the Southeast China continent, hence it may hold a key to understanding the interactions between the Eurasian and Paleo-pacific plates and geological evolution of the coastal areas in Late Mesozoic. The T3-J1 sedimentary rocks in the coastal zone are unconformably overlain by Lower Cretaceous Nanyuan Formation or occur as amphibolite facies enclaves in late Jurassic-early Cretaceous gneissic granites. The metasedimentary rocks (T3-J1) enclaves with penetrative migmatization were deformed together with the wall rocks (gneissic granites) and intruded by insignificantly deformed Cretaceous granitic plutons or dykes. Metamorphism and deformation in the late Triassic to early Jurassic (T3-J1) metasedimentary rocks are characterized by cratonward (NW) weakening. The Lower Cretaceous Nanyuan Formation is characterized by extensive folding and greenschist facies metamorphism and unconformably covered by the Upper Cretaceous Shimaoshan Group, showing no signs of metamorphism. The major stratigraphic units and tectonics in the Changle-Nan’ao zone indicate that the continental margins underwent two stages of compression (orogenesis) in Late Mesozoic. During the first episode of orogenesis, the late Triassic to early Jurassic (T3-J1) continental sediments were folded and metamorphosed. Subsequently, the folded and metamorphosed T3-J1 sedimentary rocks were exhumed together with other rocks from the depth of middle and upper crusts in early Cretaceous, accompanied by large scale synkinematic magmatism (147-135 Ma) and regional migmatization. During the second stage of compression in Late Mesozoic, the Nanyuan Formation was folded and metamorphosed. The 110-100 Ma magmatic complex, the 100-90 Ma A-type granites, and the 90-80 Ma bimodal igneous rocks in coastal areas of Southeast China might be correlated with the middle Cretaceous crustal contraction and the subsequent crustal extensions, respectively. Consequently, the two Late Mesozoic magmatic cycles (165-120 Ma and 110-80 Ma) might be controlled by the two synchroneous tectonic cycles (165-120 Ma and 115-80 Ma). Each of the Late Mesozoic tectonic cycles includes a crustal contraction and a subsequent crustal extension. It should be noted that the Late Mesozoic tectonics and magmatism in the coastal areas of Southeast China seem to be comparable with those that simultaneously occurred in the hinterland of the continent.

Abstract:Abstract：The basic characteristics of structural deformation in Kuqa Depression of, Tarim Basin is contractive structural deformation, owing to the development of a lot of thrusts and buckling folds in Mesozoic and Cenozoic strata. This paper establishes two types of model for interpreting the contractive structural deformation in Kuqa Depression based on the structural features interpreted from geological outcrop, seismic data, well-log and CEMP（Continuous Electromagnetic Profile） data, and discusses their differences in geometry, shortening extent and dynamics. One model is the “skin-contractive deformation”, a typical “A-type” subduction model. The other is the “delaminate contractive deformation”, in which both the sedimentary cover and the basement of the depression are involved in contractive deformation in respective styles, with no real regional detachment fault developed. The “delaminate contractive deformation” is considered to be more reasonable so far as the data and theoretical concepts are concerned. The model emphasizes that Cenozoic, Mesozoic and basement decoupled under lateral pressure between Tarim craton and South Tianshan Mountain affected by the capability of the strata, Cenozoic was dominated by detachment folds with break thrusts, Mesozoic was dominated by thrusts with related folds, and the basement was dominated by thrusts and faulted blocks. The shortening extents at the bottom of Cenozoic, the upper of Mesozoic and the basement of the depression are basically identical. The shortening extent ranges from 12km to15km according to length balance of Cenozoic bottom, and the depth involved in contractive deformation ranges from 20km to 26km in the front of South Tianshan Mountain according to excess area of Mesozoic in sectional plane. Therefore, the basement of the depression is uplifted in the north and is involved in the thrust. Although the intensity of contractive deformation gradually decreases from mountain to foreland and from the shallow part to the depth in theory, the Mesozoic and basement under the salt rock of Eocene in Qiulitag structural zone might still be involved in contractive structure deformation owing to a tight-closed anticline at the shallower level. The structure is trapped at the deeper level.

Abstract:Abstract：The May 2008 Ms 8.0 disastrous Wenchuan earthquake occurred in the eastern margin of Tibetan Plateau, producing 270 and 80 km-long different kinematics features coseismic surface ruptures along the Yingxiu-Beichuan and Anxian-Guanxian faults, respectively. Drilling in active fault zones, especially after large earthquakes, is an effective way to study earthquake mechanisms, in order to better understand the fault mechanisms during the earthquake process as well as physical and chemical characteristics of rocks. The Wenchuan earthquake Fault Scientific Drilling project was carried out on November 6, 2008 (178 days after the Wenchuan earthquake). Five boreholes were ultimately drilled along the Yingxiu-Beichuan and Anxian-Guanxian faults, ranging from 600 m to 3000 m in depth. This paper focuses on the cores of the first hole (WFSD-1). Petrological and structural analysis of the cores allowed the identification of the distribution and combination of fault-related rocks in the Yingxiu-Beichuan fault, and the Principle Slip Zone (PSZ) location of the Wenchuan earthquake was determined, which provided a basis for further research on earthquake mechanism.The detail analysis of the cores reveals the existence of a fault zone, which is about 100 m wide from 575m to 759 m in depth and consists of gouge, cataclasite, and fault breccia. From the top to the bottom there exist mainly cataclasite zone, fault gouge and fault breccias mixed zone, breccias zone and fault gouge zone. This fault zone lies between the Neoproterozoic Pengguan complex and Triassic Xujiahe sedimentary rocks, which is the Yingxiu-Beichuan fault zone, mainly distributed in Xujiahe Formation. The Principle Slip Zone (PSZ) of the Wenchuan earthquake was found at ~589 m with ~1 mm fresh fault gouge, which lies in the upper part of Yingxiu-Beichuan fault zone, as evidenced by logging data, and clay mineral analysis, in combination with the microstructure of the gouges. There exist similar structures between Pengguan complex and Triassic Xujiahe Formation in Hongkou outcrop with the thickness of about 190m, lying at the bottom of the Yingxiu-Beichuan fault zone. Hence, The Wenchuan earthquake fault slip cut the Yingxiu-Beichuan fault zone obliquely, indicating that Wenchuan earthquake fault might be a new high-angle thrust fault with a dip angle of 62°-65°, which did not totally follow the slip zone of ancient earthquake and might be related to the earthquake magnitude. It is the result of the long term earthquake activity and evolution from about 10-15 million years ago to the present, which formed the 100~190 m-wide Yingxiu-Beichuan fault zone.

Abstract:Abstract：Chengde basin in Hebei Province is composed of volcanic rocks of early Late Jurassic Tiaojishan Formation and coarse clastic rocks of middle Late Jurassic-early Early Cretaceous Tuchengzi Formation. Based on a sedimentological study of basin-fill of the Tuchengzi Formation, the authors have reached some conclusions. The northern and southern areas of the Chengde basin were controlled by the Fengning-Longhua thrust faults and Chengde Xian-Jiyuqing thrust faults, respectively. The rapid basin filling process of Chengde basin was the response to the strong intraplate deformation in this period. The intracontinental deformation episode started at the deposition of Tuchengzi Formation and was completed at the end of the deposition. The tectonic deformation process caused Chengde basin to form an asymmetric syncline fold. The age upper limit is constrained by the unconformity beneath volcanic rocks of the Zhangjiakou Formation with the age of 135?1Ma.

Abstract:Abstract：Seismic sedimentology has aroused much attention among geologies both in China and abroad in that it plays an important role in the exploration and production of thin reservoirs. According to the theory of seismic sedimentology and practices in continental basins, this paper puts forward a program of seismic sedimentology suitable for China’s continental basins with lots of thin sand bodies: first, the high resolution sequence framework is built up and seismic data are converted to 90°phase, then seismic processing within different frequencies and stratal slicing with different seismic attributes were conducted, lithologies in cores are correlated with stratal slicing, thin sand bodies are determined in plane with seismic geomorphology so as to define depositional systems and their evolutions, and lastly, the favorable lithological traps are predicted. With the Shahejie Formation of Qikou depression as the studied object of seismic sedimentology, the authors determined the distribution of delta of Shahejie Formation in Qikou depression and forecasted the regions of beneficial lithologic traps.

Abstract:Abstract：BSR found in the formation has been distributed since Late Miocene in the deep water area of Qiongdongnan (Southeast Hainan) Basin, influenced by the tectonic movements. The BSR is one of the important indicators to identify gas hydrate. Based on data analyses from 301 virtual points, the authors worked out the relationship between the BSR’s distribution and the tectonic subsidence. The study shows that under the influence of the Red River strike slip motion and mantle-derived basic magma eruption, there are three different tectonic subsidence acceleration periods bounded by 5.3Ma and 1.8Ma in the deep water area of the Qiongdongnan Basin, of which the third phase (since 1.8Ma) is the fastest stage. From border to center, the tectonic subsidence rate is getting higher and higher, and it changes faster in the central hollow zone than in the southern uplift zone. In the area between them it remains high. BSR is mainly observed in the borderland between secondary structure unit where the tectonic subsidence rate is high and changes faster and the area which can afford higher tectonic subsidence rates varying from 70m/Ma to 110m/Ma.

Abstract:Abstract：The new concept of maturity of the magma system emerges from the study of the physical processes of magmatic systems, from which it is recognized that not all of the crystals in igneous rocks are crystallized from their host magma. According to the ways of adding crystals to the magmatic system, the crystals in igneous rocks can be divided into three populations：solid-, melt- and fluid-crystal populations. The solid-crystal population means that the crystals exist in solid state before they are added into the magmatic system, including residual crystal sub-population and xenocryst sub-population. The melt-crystal population consists of the crystals crystallized from a melt, including crystals from the magma chambers at different depths (chamber crystal sub-population), crystals from magma conduits (channel crystal sub-population), crystals that have crystallized from progenitors of the final magma and have been ‘reincorporated’ into the final magma (antecryst sub-population), and crystals that have been crystallized after magma emplacement (matrix crystal sub-population). The fluid-crystal population is used to define crystals separated out from fluids, including crystals from the super-critical fluid (super-critical crystal sub-population), from vapor (condensation crystal sub-population), and from hydrothermal liquid (hydrothermal crystal sub-population). Such a division opens a new window for the future of genetic mineralogy of igneous rocks. Accordingly, an important duty of genetic mineralogy is to clarify the typical characteristics of various crystal populations and their forming conditions. Theoretically, the residual crystal is in thermodynamic equilibrium with the primary magma; the xenocryst is generally in disequilibrium with the host magma; the melt-crystal is in equilibrium with the magma produced at a special stage in the evolution of the magma system; the fluid-crystal is commonly in disequilibrium with magma, but a part of crystals from the super-critical crystal sub-population can be in equilibrium with the host magma. Therefore, the fluid-crystal is occasionally coexisting with the melt-crystals. The preservation of crystal populations in igneous rocks is related to the existing time of the magma system and the resorption rate of crystals. In the magma system where the magma quickly rises up and consolidates, all the crystal populations could be preserved; otherwise, only the matrix crystal sub-population is preserved. Accordingly, the number of population and the crystal size distribution can be used to qualitatively evaluate the existing time of a magma system and its dynamic conditions. Therefore, the quantitative analysis of igneous texture will be an important task in genetic mineralogy.

Abstract:Abstract：Field profiling and ETM image interpretation as well as regional geological mapping at the scale of 1:250000 led to the discovery of large scale Ngari thrust system caused by intense southward thrust in Late Cretaceous-Palaeogene and tectonic emplacement of ophiolite belts along the Bangoin-Nujiang suture in western Tibet. The Ngari thrust system mainly consists of regional thrust faults, tectonic slices of different epochs, nappes and tectonic windows of different scales, and accompanied folds of different orientations. In addition, the frontier thrusts were formed along Shiquanhe-Geji-Maigang arc belt in northern Lhasa block. Tectonic sheets of Mesozoic ophiolites, Carboniferous slate, Permian dolomite limestone, Triassic and Jurassic limestone and shale intercalated with sandstone were thrusted over Lower Cretaceous marine strata and Upper Cretaceous-Palaeogene red-beds, forming a typical thin-skin duplex with the minimal displacement of 160-180km in Ngari area. Such a thrust system was formed in 75-20 Ma according to available chronological data, corresponding to average slip rate 2.91-3.28 mm/a of southward thrust. The revelation of the Ngari thrust system is very important for better understanding tectonic evolution of ophiolites along Bangoin-Nujiang suture and reasonable evaluation of petroleum resources in western Qiangtang block.

Abstract:Abstract：Zircon LA-ICPMS U-Pb ages and Hf isotope compositions of the tuff and clastic rocks from Lengjiaxi Group and Banxi Group in the middle section of the Jiangnan orogenic belt were determined. The results reveal that the sedimentary time of the Lengjiaxi Group is 860-820Ma. On the other hand, the lower limit of sedimentation of the Banxi Group which overlies the Lengjiaxi Group in angular unconformity is ca.820Ma, suggesting the quick transformation from the assemblage between Cathysia and Yangtze to the extension of the Jiangnan orogenic belt. Zircon Hf isotope compositions exhibit a rapid increase of the initial Hf values during 850-820 Ma, indicating significant addition of the depleted mantle materials during this period. The quick increase of εHf(t) could be ascribed to the following factors: (1) most clastic materials were derived from arc igneous rocks (e.g., I-type granites) and (2) some materials were derived from the mixed substances (such as tuff) between crust-derived magma and mantle-derived magma during the quick collapse after the orogeny). In combination with previous studies, the authors hold that the plate-rift model is a most plausible geodynamic model for the Neoproterozoic tectonic evolution of South China.

Abstract:Abstract：The volcanic-intrusive complexes were dated by the SHRIMP U-Pb dating method of zircons from the Xiangshan uranium orefield, Jiangxi Province. SHRIMP U-Pb dating of zircons from 7 volcanic rocks yielded 206Pb/238U concordant ages from 133Ma to 142Ma. The weighted mean ages of two porphyroclastic lava samples are 134.6±1.0Ma (MSWD＝1.5) and 134.1±1.0Ma (MSWD＝0.65), respectively, which constrain the latest volcanic eruption in Xiangshan area at 134Ma. Two sub-porphyritic granites from Baquan in northern and Wuzhang in southern Xiangshan uranium orefield have ages of 133.3±0.8Ma (MSWD＝0.82) and 134.7±0.9Ma (MSWD＝1.08). The consistent ages of granite porphyry with porphyroclastic lava within the error range indicate that these two types of rocks were approximately simultaneously erupted or/and then intruded, probably with similar origins, as also supported by field evidence and previous geochemical analyses. A rhyodacite sample obtained from drill hole No.ZK111A-1 in the upper part of the Daguding Formation at Shutang in western Xiangshan has age of 141.6±1.7Ma (MSWD＝0.9), suggesting that the first-cycle of the volcanic eruption should have ended at about 142Ma, most probably during the Late Jurassic. The intrusive age of a quartz-monzonite granite-porphyry sample from drill hole No. ZK19-2 in Gangshangying area is 136.4±1.0Ma (MSWD＝1.7), and the age of rhyodacite-porphyry from the Ruyiting section is 137.4±1.7Ma (MSWD＝1.11), indicating an interval age of 136-137Ma between the first and the second cycle of volcanic eruption, and both the granite-porphyry and the rhyodacite-porphyry intruded during the interval time of two volcanic movement cycles. The dating results obtained by the authors and the previous researchers show that the second-cycle of the volcanic-intrusive movement in Xiangshan area ranged from 136Ma to 133Ma in time, belonging to early Cretaceous volcanic event. It is also proposed that the Ehuling Formation in Xiangshan area should be Early Cretaceous in age.

Abstract:Abstract：The Mesozoic intrusive rocks in Chabaqi area are located in the west of Nenjiang fault zone, and the east side of the study area is the joint between apophysis and graben basin. Hence the study of the structure of the study area can provide the information for the orogenic uplift of the Da Hinggan Mountains. The result of SHRIMP U-Pb zircon dating shows that the intrusive rocks were mainly formed in the early Jurassic and late Jurassic period, and the petrogeochemical characteristics show that the intrusive rocks are high-potassium and Si-saturated rocks, belonging to calc-alkaline series. Discrimination diagrams show that the intrusive rocks belong to I-type granite of crust-mantle miscibility，and they were formed in a prolonged stable environment but under different formation conditions. The early Jurassic quartz diorite and tonalite have the characteristics of extrusion type, so that they should be formed in a relatively high pressure environment, whereas the late Jurassic monzonitic granites belong to the transition type of extension-extrusion, and hence they should be formed in a high differentiation environment of relative low pressure. The spatial and temporal granite evolution heterogeneity was probably existent in the formation process. Therefore, the relationship between the formation of Jurassic granites and the thickness of the earth's crust can serve as the supporting evidence for the thinning of the earth's crust and lithosphere as well as the stretching orogenic process of the Da Hinggan Mountains.

Abstract:Abstract：To meet the demands for Pb-Zn resources, China should have more lead and zinc resource reserves to keep up with the step of modernization construction. This paper sums up the distribution and characteristics of Pb-Zn deposits in China, and analyzes the problems of enlarging Pb-Zb resource reserves. Then, based on the demand for resource potential, the authors calssified the Pb-Zn deposits in China into 7 prognostic types and 48 models. The 7 types are (volcano)-diagenetic metamorphism type, marine volcanic type, continental volcanic type, skarn type, hydrothermal type, magmatic hydrothermal type and weathering crust type. On such a basis, the discovered ore concentration areas were analyzed for Pb-Zn resource potential, and 28 successive strategic bases for Pb-Zn resources were proposed. The important bases are descrfibed in detail in this paper. Through potential analysis, some suggestions and opinions concerning the further work arrangement are put forward in this paper.

Abstract:Abstract：Located at the northernmost corner of the Deerbugan metallogenic belt, the newly found Chalukou deposit is the largest molybdenum polymetallic deposit ever discovered in Northeast China. It contains 1.24 Mt of Mo (metal), 0.26 Mt of Pb-Zn and 2773 t of Ag. As a part of the evaluation project on the molybdenum deposit, mineral exploration around the Chalukou deposit is still under way. During the Mesozoic Yanshanian orogeny, intense extensional tectonic and igneous activities resulted in the intrusion of large-scale acid volcanic rocks and granitoids at Chalukou and its neighboring areas. The Chalukou granite porphyry and rhyolite porphyry stocks were emplaced in the Jurassic volcano-sedimentary sequence controlled by NE- and NW-trending fault zones. Rock-forming minerals of the two porphyry stocks are mainly quartz, microcline, microperthite and plagioclase associated with minor biotite and sericite. Accessory minerals are magnetite, apatite, zircon, sphene and allanite. The two porphyry stocks are petrochemically characterized by relatively high SiO2, K2O, F, Rb, Nb, U, Th,Y and Yb and obviously low CaO, Fe2O3+FeO, MgO, Sr, Ba and REE, with positive ?Nd(t) value. Molybdenum mineralization occurs within the Chalukou porphyry stocks and volcanic rocks as stockwork, veins, veinlets and disseminated blocks. The molybdenum ore consists of pyrite, chalcopyrite, molybdenite, sphalerite, galena, magnetite, pyrrhotite, K-feldspar, fluorite, quartz, sericite and chlorite. As the most important economic molybdenum mineral, molybdenite occurs in the forms of impregnation, radioflake, thin film, aggregated flakes and veinlet. Re-Os isotopic age dating of eight molybdenite separates from the Chalukou deposit yielded an isochron age of 146.9 ± 0.8 Ma and model ages ranging from 146.2 to 149.1Ma with an average value of 147.4Ma. As the Re-Os isochron age is in agreement with field geological evidence, the authors hold that the Re-Os isochron age represents the major ore-forming time of the Chalukou deposit, which corresponded to geodynamical setting of intracontinental extension after the collision of the Siberian plate and North China-Mongolian tract. Hydrothermal alteration at Chalukou shows rough zonation of K feldspathization, greisenization, silicification, and propylitization from the two porphyry stocks outwards. Of these alterations, silicification and greisenization are well developed, and have intimate relationship with molybdenum mineralization. Studies show that all these ore-forming materials, dynamic forces and fluids might have been provided by the Yanshanian granitoid magma. Moreover, the accumulation conditions of the ore-forming materials were offered by the NW- and NE-trending lineament and ring fractured zone as well as Jurassic volcano-sedimentary rocks. A comparative analysis indicates that the Chalukou deposit belongs to high-F porphyry type molybdenum deposit. The Late Jurassic lithosphere stretching and asthenosphere upwelling might have resulted in the melting of the thickened lower crustal material, and then produced molybdenum-rich granitoid magma. When the magma moved along structures developed within the upper crust, ore-bearing fluid derived from condensation fraction of the magma filled the structures and replaced country rocks, thus forming the deposits. Therefore, it is believed that the Chalukou deposit was a product of the Late Jurassic intraplate granitoid magma in the northeastern part of the North China-Mongolian tract. The genetic model and mineral exploration criteria of the Chalukou deposit can also be used as useful tools during the comprehensive evaluation of concealed molybdenum deposits in northern Da Hinggan Mountains.

Abstract:Abstract：As one of special mineral species deposits in China, molybdenum deposits have got considerable prospecting breakthrough in recent years. Molybdenite, widely distributed in a variety of endogenous Mo deposits, is a molybdenum-bearing mineral with the most significant econonic significance. In this study, the authors chose molybdenite from 57 molybdenum deposits for ICP-MS REE dating. The results show that the total REE values in molybdenum deposits are between 10.99 and 3374μg/g (concentrated between 10.99 and 600μg/g). The high REE amounts in molybdenite were formed in Yanshanian period (concentrated in the Middle Jurassic - Early Cretaceous), North China has higher REE than South China, and independent Mo deposits or Mo polymetallic deposits have higher REE than other deposits characterized by associated Mo mineral assemblages. REE distribution patterns of molybdenites show diversity, but the patterns are not controlled by metallogenic ages, types and mineral assemblages in different ore concentration areas. Molybdenites are significantly enriched in LREE, and have strong negative Eu anomalies (δEu= 0.01~0.80), negative Ce anomalies (δCe=0.24~1.06, Most are less than 1) and positive Sm anomalies (δSm=1.29~79.42). According to these characteristics and distribution patterns of REE in molybdenite, 6 categories of molybdenite can be identified, reflecting the different geneses of molybdenite or different natures of ore-forming fluids captured in the process of molybdenite crystallization. Based on the experimental results of melt/fluid, the authors infer that molybdenum-forming fluids are usually enriched in CO2, Cl- (may be also rich in F-) and some reducing gas compositions, indicating a reducing environment. The quartz vein-type deposits, however, were formed in more oxidative environment than porphyry deposits.

Abstract:Abstract：Re-Os dating of molybdenite is an efficient means to restrict the time of mineralization. The age of mineralization of the Xiongcun porphyry copper-gold deposit is confined between 171 Ma and 175 Ma based on this study and other data available. No.Ⅰ ore body of the Xiongcun deposit was affected by later magmtic thermal event. Molybdenite contains trace K-Si silicate enriched in Re. As a result of this event, the Re content of molybdenite is one to four times higher than that of molybdenite in No.Ⅱ ore body and No. Ⅲ ore body, and the age of molybdenite in No.Ⅰ ore body is younger than the real age. The authors also compared the Re content of molybdenite between this deposit and other porphyry-skarn deposits within this belt and found that the content of Re shows systematic variation. The Re content of the Xiongcun porphyry copper-gold deposit is one order of magnitude high than that of Miocene porphyry deposits and two order of magnitude higher than Paleocene to Eocene porphyry-skarn deposits. The Re variation is related to the source of metal, the content of molybdenum, the composition of magma and the physical/chemical condition of magmatic-hydrothermal solution.

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.

Abstract:Abstract：Exploration geochemistry has made great achievements both in basic knowledge of dispersion and distribution of elements and applications in mineral exploration since it was born in the 1930s. The author has generalized its growing up landmarks, reviewed its theoretical studies and contributions to mineral discoveries in the past 80 years, and described most active research fields at present. The growing up progress can be seen from the landmarks such as publication of classic text books, teaching of exploration geochemistry in universities, issuing of journals of geochemical exploration, establishment of associations of exploration geochemists and initiation of international exploration geochemistry symposia. Theoretical studies have been based on dispersion and distribution patterns of elements and mechanisms which control the dispersion and distribution of the elements. Exploration geochemistry, particularly applied to regional geochemical surveys/mapping, has delineated numerous geochemical anomalies leading to mineral discoveries all over the world. At present, the most active research fields are focused on 1）nano-scale and molecular-level understanding of migration mechanism of elements from covered mineral deposits, 2) regional-scale geochemical mapping; 3) global-scale geochemical baselines.

Abstract:Abstract：On the basis of studying related geochemical data of element distribution in 500 sets of rice seed samples and the cultivated soil and 300 sets of wheat seed samples and the root soil from some typical areas of Jiangsu Province, this paper has reported the bioconcentration factors (BCF) of Cd, Hg, Cu, Pb, Zn, Cr, As, Se, Mo, Mn, Fe, K, Ca and Mg which are distributed in milled rice and wheatmeal. Statistical results show that there exist obvious differences in BCF of different elements：usually BCF of Pb, Cr, Fe etc. is lower than 1%, BCF of Hg, As, Mn, Ca etc. is equal to 1% - 10%, the average BCF of Mo is the largest and the average BCF of Fe is the smallest. It is found that element content exceeds limited-standard in the studied milled rice or wheatmeal samples; for example , Pb content is 15% higher than the limited-standard proportion, and the Cd content is 6% higher than the limited-standard proportion. According to statistical data, there is not direct relationship between BCF distribution differences of related elements and element content exceeding the limited-standard within the above-stated milled rice or wheatmeal samples. Furthermore, it is pointed out that the controlling indicators of BCF distribution include probably soil pH, total organic carbon (TOC), cation exchange capacity (CEC), boron (B) concentration, and so on. There exists obvious negative correlation between the BCF of such elements as Ca and Mg and soil pH, and the correlated coefficient of the BCF of Cd versus soil pH is -0.94 related to the milled rice. The same environmental indicator in soil probably has different effects on BCF of different elements, their correlation can be positive or negative, but all correlations have to be set up with certain condition limits.

Abstract:Abstract：During the performance of the regional geological survey project, the authors, based on several typical geological profiles and drill holes, discussed the distribution regularity of Holocene strata and studied the distribution characteristics of landform in Lixiahe area. Then the vegetation change and palaeoclimatic and palaeoenvironmental variations in the area since 10 ka BP were analyzed and investigated. According to the results obtained, the natural environment changes in Holocene in Lixiahe area went through four stages： (1) From 10 to 7.5 ka BP, lakes and swamps were widely distributed, and some parts of the area were affected by the sea water. (2) From 7.5 to 4.0 ka BP, a transgression occurred in this area, and the natural environment was mainly composed of tidal flat, shallow marine foreshore and lagoons. The greatest transgression could reach the area west of the Great Canal, but a part of the area was not influenced by this transgression. (3) From 4.0 ka BP to 1128 AD, the regression occurred, the coastline stayed for a long time along the Fangong embankment, and the shell bar of Xigang was formed. Consequently, the west part of Lixiahe area was often impacted by the sea water. (4) From 1128 AD, because the Yellow River captured the Huaihe area, the surface water system in Lixiahe area changed, and the shoreline in the area withdrew continuously eastwards. Since then, the area has not been impacted by the sea water again.

Abstract:Abstract：In this paper, based on analytical results of 73 oxide samples of "Wushan loess", the authors analyzed and discussed oxide geochemical characteristics of "Wushan loess" and their recorded paleoclimate characteristics. In the average content of the main chemical compositions in "Wushan loess", SiO2, Al2O3, Fe2O3, are higher than those in Luochuan loess and Ganzi loess. The values are close to the values of Luochuan paleosols but lower than those in Xuancheng aeolian red clay in Anhui and Xiashu loess profile in Zhenjiang. The values of SiO2, Al2O3, Fe2O3 and TiO2 in "Wushan loess" gradually decrease with depth, whereas those of FeO, CaO, Na2O and P2O5 gradually increase. In Wushan section, the Fe3+/Fe2+ ratio curve shows a significant positive correlation with the total iron content curve but a negative correlation with the curve of SiO2/(Al2O3+Fe2O3). From old to young, values of residual coefficients and weathering indexes become smaller and smaller, but de-alkali coefficients become larger. In the period of accumulation of "Wushan loess", the ancient climate in this area was partially warm and partially humid in general. The intensity of leaching and oxidation that sediments experienced was equivalent to Luochuan paleosols, it was significantly stronger than the north Luochuan loess and Ganzi loess of western Sichuan but weaker than the eolian red clay in Xuancheng of Anhui and Xiasu loess in Zhenjiang. In this profile, from bottom upward, the acidity in the deposition was moderately weakened, the alkalinity was enhanced, the weathering intensity that the supergene band suffered became weaker and weaker. Eolian depositional environment changed from the beginning of partially hot and partially humid gradually to dry and cold. In the period of accumulation of "Wushan loess", paleoclimate evolution showed stage characteristics. The section was divided into upper and lower parts with 6-6.5 m as the boundary; the paleoclimate in the lower part was partially hot and humid, and partially cold (dry) and warm (wet), with frequent fluctuation, whereas the upper part was relatively dry and cold, its climate was relatively stable, and the fluctuation was relatively small.