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.

Abstract:Abstract：This paper deals with zircon SHRIMP dating of the Niuxinshan and Minleyaogou granites in the central segment of the North Qilian Mountains, NW China. The dating results indicate that the ages of the Niuxinshan granite and Minleyaogou granite are 476 and 463 Ma respectively. Petrogeochemistry shows that both granite intrusions have the features of active continental-margin magmatism. On the basis of these features, combined with the tectonic locations of granite occurrence and field observation data, the authors think that south- and north-directed subductions of the North Qilian oceanic plate took place in the Early Paleozoic, of which the southward subduction resulted in the formation of the Nixinshan granite (476 Ma) and the northward subduction gave rise to the Minleyaogou granite (463 Ma).

Abstract:Abstract：There is a long dispute over the age of medium- and high-grade metamorphic rocks in the Altay area, including gneiss in Qinghe. Li Tiande et al. assign medium- and high-grade metamorphic rocks in the Chonghuer-Altay-Qinghe area on the southern margin of the Altay Mountains, Kuwei-Wuqiagou area of Fuyun County and seat of Fuyun County to the Paleo- and Mesoproterozoic Kemuqi Group and Neoproterozoic Fuyun Group, which has attracted wide attention and debate, especially disputes over the age of gneiss in the Mayin Obo fault belt southwest of the seat of Qinghe County. The authors have performed zircon U-Pb SHRIMP dating of the gneiss. Although they failed to obtain concordia ages, the data of ages in different time intervals still have certain geological significance. The abundant age information of Precambrian zircons affirms the possibility of the occurrence of Precambrian strata in the Altay region and determines that the gneiss should form earlier than the Late Paleozoic.

Abstract:Abstract：The Xinyang Neoproterozoic granitoid gneiss, identified from the Paleoproterozoic Qinling Group complex on the northern margin of the western Qinling orogen, is located to the east of Xinyang town of the northwestern Tianshui. The internal CL images of zircons in granitoid gneiss show that the zircons have higher Th/U ratios and clear oscillatory zoning, indicating an igneous origin. The acquired LA-ICP-MS zircon U-Pb weighted average ages (938±4 Ma and 981±5 Ma) indicate that the granitoid gneiss was formed in the Neoproterozoic and that a tectono-thermal event (subduction and collision) occurred on the northern edge of the West Qinling during the Jinningian, which is presumed to be the response of the convergence of the supercontinent Rodinia in the West Qinling.

Abstract:Abstract：Myrmekite is commonly developed in the high-grade gneisses of the Chinese Antarctic Zhongshan Station area (Larsemann Hills). The occurrence of myrmekite is usually the symbol of the association of plagioclase and K-feldspar. Some plagioclase-quartz rims and K-feldspar rims along mineral grains are generally related to the texture. The anorthite content of the plagioclase in myrmekite may be lower or higher than the content of the main plagioclase in the rock, and the former shows a wider composition range than the latter. The origin of myrmekite is mainly related to the change of felsic minerals. Others factors like the decomposition and exsolution of K-feldspar, decomposition of quartz and biotite and even decomposition and exsolution of plagioclase sometimes may be involved. The exsolved components corrode and replace the preexisting minerals (predominantly K-feldspar) and myrmekite is produced simultaneously. Although not a necessary condition, deformation is favorable for the formation of myrmekite. The formation of myrmekite in felsic rocks also implies the decompression process in PT evolution. The components responsible for the formation of myrmekite were mainly derived from the system itself, rather than from the outside environment. In combination with its correlation with related textures and analysis, the formation of myrmekite is the result of differentiation of felsic components in the late stage: the differentiation of K and Na (Ca) resulted in the precipitation of Na (Ca)(2)+ and mobilization of K+ as well as migration of SiO2 to some degree. The released and migrating components tend to be more alkaline. This differentiation is the result of adjustment of the composition and textures inside the rocks, but the activity of the components is confined to the scale of several grains. The presence of myrmekite may represent cotectic crystallization between plagioclase and quartz and exerts a buffering effect on the composition of neogenic plagioclase. The process approaches the solution feature rather than the magma feature. In addition, the presence of myrmekite suggests the essential end of the activities of all the components except that of H2O.

Abstract:Abstract：The Late Paleozoic granites occurring in the Songshishan area, Central Kunlun Mountains are composed of quartz diorite, tonalite, granodiorite and monzogranite. The rocks have low contents of SiO2 (56.42%-73.70%) and K2O (1.70%-3.56%) and are poor in alkalis with Na2O+K2O=6.13% on average and rich in sodium with Na2O=3.49% on average and K2O/Na2O= 0.51-0.99 and aluminium with Al2O3=14.90% on average. The granites as a whole are of magnesian, sub-aluminous-weakly peraluminous calc-calc-alkaline series. Ba, U, Nb, Ta, Sr, P and Ti are pronounced but not strongly depleted, while Rb, Th, K, La, Nd, (Zr+Hf+Sm) and (Y+Yb) are comparatively concentrated. ΣREE values average 105μg/g and LREE values are enriched with (La/Yb)N=13.91 on average. δEu values are weakly depleted or show no depletion, with δEu=0.85 on average. Quartz diorite is notably deviated from the evolution line in the Harker diagram of main oxides and has the lowest δEu values, monzogranite has the highest δEu values, the data points of the rocks fall in different fields of the C/MF-A/MF diagram, the oxide variation curves neither show straight lines nor form hyperbolas on the syn-denominator diagrams, the 4 types of granites do not show the trend of differentiation in the La/Sm-La diagram, and there are mafic microgranular enclaves of magma mingling origin in granites—all these suggest that the parent rocks and magma of the granites have multiple sources and that magma mixing occurred during the formation of the magma. The characteristics of the trace element spidergram, various oxide and trace element diagrams for tectonic environment discrimination and regional tectonic framework reveal that the rocks were formed in an island-arc environment.

Abstract:Abstract：Super-magnesium peridotite is the main host rock of boromagnesite ore in the Houxinyu boron deposit, Yingkou, Liaoning Province. The geological and geochemical characteristics of the rock are as follows: ① The rock occurs as concordant belts and lenses in magnesium-rich borate rocks of a boron-bearing rock sequence of the Paleoproterozoic volcano-sedimentary rock series, and is almost all made up of forsterite and has a blastic exhalative-sedimentary fabric. ② The major elements indicate that the rock is rich in magnesium and iron. ③ Inactive trace elements such as Zr, Hf and Ta are rich, which is similar to the case of typical ultramafic rocks; the lower contents of Cr and Ni suggest a non-primitive magma, and Nb*> 1 and the (La/Yb) N-(Yb) N diagram both indicate a mantle origin for the rock. ④ The total REE content ranges from 7.41×10-6 to 46.82×10-6, being similar to that of the upper mantle; the fractionation of LREE and HREE is not pronounced, with a pronounced negative Eu anomaly; and the chondrite-normalized REE patterns of the rock are “v”-shaped, being similar to those of dunite. ⑤ The values of εNd range from -7.51961 to 9.0654, which indicates the feature of mixing of the mantle and crust. From the above-mentioned geological and geochemical characteristics, it may be inferred that the rock is magnesium-rich rock left after relatively high degrees of partial melting of mantle peridotite contaminated by the crust.

Abstract:Abstract：The latest Paleoproterozoic Period represents one of the most important transition stages of the evolution of the North China craton, but its relevant tectonothermal episodes and tectonic framework are rarely documented in detail. In this paper, the tectonic evolution and genetic model are discussed based on the regional tectonic analysis, combined with the latest isotopic age dating. The NW-trending Taihang-Hengshan mafic dike swarms (1.80-1.77 Ga) correspond to failed arms of the Yanliao and Taihang aulacogens, which formed an asymmetric aulacogen system with triple arms. The relevant anorogenic magmatism consists (in order of time) of granite and pegmatite intrusion (1.85-1.80 Ga), injection of basic dike swarms (1.80-1.77Ga), anorthosite,alkaline granite and rapakivi granite intrusion (1.71-1.70 Ga) and volcanic eruption (1.68 Ga). As indicated by the regional correlation of the underlying basement complexes and isotopic age dating, large-scale domal uplift took place in the Yanliao-Taihang area at ~1.80 Ga, with an uplift diameter up to 1000 km. The core area of the domal uplift is located at the center of the Yaoliao-Taihang aulacogen system. The uplift of the basement coincided with the supracrustal extension structures and anorogenic magmatism in time and space, which supports the mantle plume model for a rational interpretation of the above-mentioned regional uplift and extensional break-up event in the latest Paleoproterozoic episodes of the North China carton.

Abstract:Abstract：The Tanlu fault zone has experienced two main development stages since the Hercynian. The first stage was a stage of the development of the Tanlu fault zone sensu lato. In the Late Triassic-Early Jurassic, the collision between the Yangtze plate and North China plate gave rise to a boundary of the two plates, which was of overthrust nature, belonging to the Tethys tectonic domain sensu lato. In the second stage, since the Early Cretaceous, the fault has developed into a wrench fault zone, which belongs to the wrench system of the circum-Pacific tectonic domain sensu stricto. Lithofacies and paleogeography shows that the junction between the Yangtze plate and North China plate was initiated in the early Late Permian and that the Indosinian Tanlu fault zone was a gently “S”-shaped block amalgamation boundary of NE and NNE trends, which displays the nature of a residual NE- and NNE-trending, oblique overthrust zone in the present Tanlu fault zone, while the middle and lower tectonic layers show ductile overthust deformation and the upper tectonic layer shows the deformation inside a foreland fold-thrust zone. Stress field analysis indicates that: as early as the late Early Triassic nearly N-S compression occurred at shallow levels of the crust and sinistral strike-slip movement was initiated; in the late Early Cretaceous the fault zone began to turn into the extension stage, which was consistent with the extension in eastern China; and in the Neogene it underwent nearly E-W compression, resulting in thrusting and dextral strike-slip movement.

Abstract:Abstract：The paper analyzes various geological records closely related to the earliest Pleistocene climatic and environmental changes in the Zanda basin, Ngari, Tibet. The analytic results indicate that the earliest Pleistocene deposits in the study area may be divided into three sedimentary facies and four lithozones and that the paleoclimatic and paleoenvironmental changes may be divided into four stages: ① the 2.68-2.45 Ma stage, which is marked by alluvial and diluvial deposits, when freeze-and-thaw folds started to appear and the vegetations were dominated by arbores, mainly including Pinus, Chenopodiaceae and Artemisia, indicating a cool-temperate alpine climate; ② the 2.45-2.11 Ma stage, which is also marked by alluvial and diluvial deposits, when most freeze-and-thaw folds in strata were contorted, herbaceous plants increased rapidly, showing the features of the shrub-grassland climate, and the climate became cool and dry; ③ the 2.11-1.49 Ma stage, which is marked by alluvial-diluvial and periglacial deposits (mainly periglacial deposits), when the freeze-and-thaw folds increased, there appeared cryophilic ostracods, and the quantity and varieties of herbaceous plants reached a maximum and the shrubs also increased relatively, showing that the climate became more and more arid; and ④ the 1.49-1.36 Ma stage, which is marked by glaciolacustrine deposits, when the freeze-and-thaw folds appeared extensively in the strata, the abundance of cryophilic ostracods was very high and the herbaceous plants decreased slightly but pteridophytes increased significantly, showing the features of the cold-dry grassland climate.

Abstract:Abstract：The analysis of the depositional-tectonic transition based on the study of the sequence stratigraphy and lithofacies-paleogeography is an important idea to study the temporal-spatial evolution of the depositional systems. From such an analysis, the authors find out that in the Jurassic southern Qiangtang went through the evolution from the passive continental margin through the failed foreland to an uplift which was finally eroded. The environment of formation of source rocks in southern Qiangtang has been preliminarily determined. During four marine transgressions there occurred two depositional cycles from terrigenous clastic rocks to carbonate rocks. During the four depositional-tectonic transitions, three sequences of black shale were developed, which belong to passive continental-margin source rocks (one sequence) and foreland source rocks (two sequences) respectively. They provide a material basis for petroleum evaluation of the Jurassic southern Qiangtang basin.

Abstract:Abstract：The Lower Cambrian in the Upper Yangtze region, especially in Guizhou and its adjacent areas, is completely developed and marked by a succession from black shales to carbonate rocks. The drowning event of the platform that occurred at the turn from the Sinian to the Cambrian resulted in the formation of a series of black shales of anoxic basin facies represented by the Niutitang Formation in the study region. With shallowing of the sedimentary environment a sequence of carbonate rocks represented by the Qingxudong Formation formed at the top of the Lower Cambrian. Thus the Lower Cambrian forms a second-order sequence, which may be subdivided into five third-order sequences, forming a regular cyclic succession of transgression-regression. The third-order sequences in the second-order sequence form a regular vertical stacking pattern. From the bottom to the top, the third-order sequences change from the succession of “CS (condensed section)+HST (highstand systems tract)”to the succession of “TST (transgressive systems tract)+CS+HST”, and correspondingly the drowning-type sequence boundary changes to the pronounced exposed hiatus-type one, implying the similarity between the second-order sequence and the third-order sequence in respect to lithofacies organization. This temporal change produced some differences in different paleogeographic settings. From northwest to southeast, the sedimentary environment deepened and the Lower Cambrian became thin and changed into a condensed succession that cannot be subdivided into third-order sequences. On the basis of the sequence stratigraphic divisions at typical sections with different paleogeographic environments and according to the elementary features of the third-order sequence, i.e. the regularity of sedimentary facies succession in space and the synchroneity of environmental changes in time, we may establish a sequence stratigraphic framework that can demonstrate “two types of facies change surface and two types of diachroneity” in the stratigraphic record. This sequence stratigraphic framework shows that the Lower Cambrian is a complex and regular stratigraphic succession, representing the growth process of the carbonate platform with the condensed succession as the base. Concomitantly with the rapid transgression in the Early Cambrian, the ecological space expanded, which formed the antecedent conditions of paleogeographic setting for the “Cambrian explosion of life”. In addition, the very complex, close relationship between the depositional events and the biological diversity events means many problems that remain to be further studied in the future.

Abstract:Abstract：The Paleogene in the northern Jiangsu basin may be divided into three tectonic sequences in light of the plate tectonic theory and sequence stratigraphic theory; they are Paleocene(TS1), Eocene(TS2) and Oligocene (TS3). On that basis, maps of lithofacies and paleogeography of tectonic-sequences in various geologic epochs of the Paleogene in the Subei basin have been compiled with the tectonic-sequence boundaries and the maximum flooding surfaces as the boundaries and the lake basin lowstand systems tract and lake basin highstand systems tract as the map-making units, and the lithofacies and paleogeographic characteristics and evolution of various tectonic sequences have been studied. These provide a more reliable basis for the prediction and assessment of favorable areas for petroleum exploration in the Subei basin.

Abstract:Abstract：Chronostratigraphic division of the Jixi and Longzhaogou Groups has been made using the latest paleontological and magnetostratigraphic data and the ages of these two groups have been determined to be the Early Cretaceous Valaginian-middle Albian. Many methods such as the sequence stratigraphic approach, basin dynamic approach, event stratigraphic approach and correlation of the lake- (sea-) level fluctuation curve of basins and global sea-level fluctuation curves were used to make an integrated correlation of the two groups. It is confirmed that the two groups have an isochronous and heteropic relationship in the background of the same tectonic-subsidence cycle. The Longzhaogou Group may be divided in ascending order into four formations: the Peide Formation, Qihulin River Formation, Xiayunshan Formation and Chaoyang Formation, which laterally correspond with the Didao Formation, Chengzi River Formation, Muling Formation and Dongshan Formation of the Jixi Group respectively. The results of this study have great guiding significance for the further discussion of the Mesozoic land and sea change mechanism, establishment of the stratigraphic and tectonic frameworks and coal deposit prediction in eastern Heilongjiang.

Abstract:Abstract：The southern margin of the Kuqa depression with abundant petroleum resources and multiple reservoir-seal assemblages has great potential for petroleum exploration. Studies of trap formation, hydrocarbon generation history and organic inclusions show that there are two hydrocarbon-generating stages on the southern margin of the Kuqa depression. The first discharge of mature petroleum occurred at the end of the deposition of the Kuqa Formation (at 5 to 2 Ma BP), and the second discharge of high-maturity oil occurred from the Quaternary to present (at 2 to 0 Ma). The key factors for controlling petroleum accumulation are connection of sources by faults, good reservoir-seal assemblages, effective traps and their matching relation with hydrocarbon accumulation periods. Other factors are the tectonic evolution setting of a paleo-uplift, characteristics of formation of petroleum accumulations in multiple stages (mainly in the late stage) and favorable preservation conditions. The petroleum accumulation-forming model is the formation of petroleum accumulations in the early stage and condensate gas accumulations in the late stage. The authors propose that recent petroleum exploration should focus on Meso-Cenozoic structural traps such as the eastern Qiulitag structure with relatively intense structural deformation, anticline and fault-anticline of the Yaken gentle slope structural zone and Yangbei structural zone of the Yangxia subbasin.

Abstract:Abstract：The Inggen-Ejin Qi basin, Inner Mongolia, is a Meso-Cenozoic continental basin, and pre-Mesozoic rocks constitute its basement. It entered the stage of downfaulted basin development in the Late Triassic-Jurassic and the stage of complete development in the Early Cretaceous. The Late Cretaceous was a subsidence stage and later the basin was in a state of compression and uplift. In the basin there were developed a Mid-Lower Jurassic petroleum-bearing system and a Lower Cretaceous petroleum-bearing system, and some subbasins have superior source, reservoir and seal conditions and combinations. Exploration practice has confirmed that there occurred hydrocarbon migration and accumulation, showing that the basin has good petroleum prospects. At present it is necessary to grasp the key exploration targets and, proceeding from favorable areas (zones) and traps, pay attention to the characteristics of the lacustrine sedimentary evolution and influences of magmatic rocks on the evolution of source rocks and petroleum accumulation. Only in this way, can a breakthrough in petroleum exploration be made and will a new situation of petroleum exploration be opened in the area.

Abstract:Abstract：Mud diapirs are characteristic anomalous seismic-geologic bodies in the Yinggehai basin on the northern margin of the South China Sea and have the less compact, abnormally high-pressure and -temperature and low-density and -velocity geophysical characteristics. They show pronounced zoning and are distributed en echelon in a nearly N-S direction along the northwest trend of the basin. The origin and distribution of the mud diapirs were controlled mainly by the combined action of the great abnormally high-temperature and -pressure potential energy produced by rapid subsidence of the basin and inequilibrium between the filling-compaction of rapidly deposited sediments and fluids squeezed out and the dextral strike-slip extension of regional basin-controlling faults in the late stage. The natural gas and CO2 migration and accumulation were effectively controlled by the effective combination of the upward intrusion of the late-stage mud-diapir thermal fluids and their accumulation conditions.

Abstract:Abstract：The Yangshan gold deposit, located in the Sichuan-Shaanxi-Gansu border region, is a superlarge finely disseminated gold deposit recently found in China. δD and δ18OH2O analysis of quartz veinlets in ores shows that the ore fluids of the deposit are dominated by magmatic water, and the δ34S analysis of various sulfides indicates that sedimentary sulfur and magmatic sulfur coexist in the gold district and show significant difference in δ34S, while the sulfur in metal sulfides in the ores is mainly of magmatic origin. δ13C analysis indicates that both magmogenic carbon and sedimentary carbon exist in the gold deposit. K-Ar, 39Ar-40Ar, Rb-Sr and U-Pb isotopic datings show that plagiogranite porphyry dikes originated in the Early Jurassic, and in addition, Early Cretaceous and early Paleogene buried intrusions do also exist in the gold district and their related hydrothermal activities also exhibit the feature of repeated occurrence. Based on the data and other analyses, the authors further discuss the genesis of the deposit and think that：a sequence of hydrothermal carbonaceous, siliceous and argillaceous sediments formed in the area in the Devonian and gold was primarily concentrated in the process of regional low-grade metamorphism in the Indosinian metamorphism; afterwards multiple magmatic activities occurred in the district and their related ore fluids and materials migrated along the Anchanghe-Guayinba fault and were concentrated and stacked in favorable structural sites, thus resulting in the formation of the Yangshan gold deposit.

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.

Abstract:Abstract：SEDEX lead-zinc deposits in the Xicheng(Xihe-Chenxian) area, Gansu, have long been divided into the reworked sedimentary type of the south ore belt and the metamorphic sedimentary type of the north ore belt. The two types show appreciable differences in host horizon, sequence of host strata and geological characteristics. Comparing the geological and geochemical characteristics of the two ore belts, the authors find that the two ore belts have much more similarities than differences. The sequence of the host strata in the Changba-Lijiagou deposit in the north ore belt is inverted, with limestone lying below and schist above, being similar to that in the south ore belt. In the Xicheng basin, there are several nearly E-W-trending lead-zinc ore belts, and the north ore belt is only one of them. The differences of the two ore belts are mostly manifested in the manner of late-stage reworking. The reworking of the Changba-Lijiagou deposit occurred in a relatively “dry and enclosed” system and thus the intact striped-banded sedimentary character may be found. By contrast, the reworking of many lead-zinc deposits in the south ore belt occurred after the in-situ ore-forming material was transported and precipitated and concentratied in a structural saddle in an “allochthonous”, “wet” (through hydrothermal processes), relatively open environment, with some exotic material introduced into it. The cause for the difference in the manner of reworking is the difference in the metamorphic grades related to acid intrusive magmatism in the study area in the Indosinian period.

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.

Abstract:Abstract：A mantle mineral assemblage consisting of 70－80 unusual varieties of minerals has been found in chromitite of the Luobusa ophiolite in the Yarlung Zangbo ophiolite zone, Tibet. This mineral assemblage includes a spinel-group mineral with a special composition. The mineral occurs as inclusions in arsenopyrite. The average chemical composition for 28 grains of the spinels is as follows：Na2O 1.58%, MgO 7.52%, Al2O3 36.59%, SiO2 44.45% and FeO 8.74 (%), with minor CaO and TiO2. Laser Raman spectrometry shows that several grains have the Raman spectrum of franclinite (zinc-iron spinel Zn Fe2O4). According to the crystal structure and chemical composition, the spinel ( franclinite) has two formulas, i.e.：(Mg0.52 Na0.14 Fｅ0.32 Al0.74)1.72 (Si2.00 Al1.20)3.20 O8 and ( Mg0.52 Na0.14Fe0.32 Si0.50)1.48(Si1.50 Al1.94)3.44 O8. The two formulas both show that the six-coordinated Si cations occupy octahedral sites of the crystal structure of the spinel. Experiments demonstrate that silicate with six-coordinated Si has the UHP nature and should be derived from the 400－670 km depth equivalent to the transition zone of the Earth. This indicates that the magmatism of the Yarlung Zangbo ophiolite (paleo-oceanic lithosphere) may have reached the transition zone. It is possible that the mantle plume might transport UHP minerals such as silicon spinels from the transition zone to the shallow level of the upper mantle.

Abstract:Abstract：The mineralogical and chemical characteristics of tourmaline in the Houxianyu boron deposit, Liaoning, are analyzed and their significance for the formation of rocks and deposits is discussed. The tourmaline in the study area belongs to the magnesium tourmaline-iron tourmaline series (schorl-dravite solid solution series) and its Mg/Fe has close spatial and temporal relations to borate orebodies. Tourmalines with different modes of occurrence show marked differences in color, size, shape and zonal features. The content of Mg is quite high in all zones of tourmaline near the borate orebodies and has a general trend of decrease from the center to edges, whereas the iron content is quite high in all zones of tourmaline far away from the borate orebodies and has a general trend of decrease from the center to edges. The tourmaline content is generally higher in the hanging wall than in the footwall. Tourmalinite mainly appears near borate orebodies and there is a pronounced positive correlation between Mg/Fe and Na2O in tourmalines far from the borate orebodies. The above-mentioned chemical characteristics of tourmaline reflect the features of the evolution of fluids during the formation of rocks and deposits. The older tourmalines formed by metasomatism of the boron-rich part in sediments. During the evolution of the evaporite basin, the contents of Mg, Na and K in fluids increased, which induced zoning of Mg/Fe. All the mineralogical and chemical characteristics of tourmaline indicate that tourmalines are of metamorphosed sedimentary origin and hydrothermal metasomatic origin and that the formation of tourmalines is closely related to the deposition of borate.

Abstract:Abstract：The western Longdong basin is situated in an overthrust belt on the western edge of the Ordos basin, where Neoproterozoic-Lower Paleozoic carbonate rocks are exposed or buried at shallow depths, forming a N-S-trending karst water concentration zone. The karst-fissure water system is analyzed and discussed intensively by using the method of structural control on water and hydrochemical isotope analysis. The spatial distribution of karst water in the area is controlled obviously by a N-S-trending overthrust belt, the water-storing space is mainly karst fissures and the karst development and karst water concentration are mainly controlled by structure. The hydrochemical features of karst groundwater in the south are notably different from those in the north. The hydrochemistry in the Pingliang-Huating area in the south-central part with superior recharge conditions of groundwater is mainly determined by the aquifer lithology and its occurrence conditions. Karst groundwater mainly originates from meteoric water, while the buried karst groundwater is mixed water from multiple sources. Based on the spatial distribution, features of the hydrodynamic field and recharge, runoff and draining conditions of karst groundwater, the whole karst area is divided into three relatively independent karst groundwater systems, namely, the Pingliang, Huating and west Huanxian systems, which may serve as a basis for water resource evaluation in the karst area. These views have great scientific significance for a better understanding of the characteristics of occurrence and concentration and mechanism for formation and evolution of karst water in arid and semiarid areas of northwestern China and exploitation and utilization of karst water resources in the study area.

Abstract:Abstract：The soil eco-geochemical baseline is a reference standard for evaluating the geochemical micro-effect induced by artificial disturbance. It has great significance in regional eco-geochemical survey and evaluation and environmental geochemical research. The paper presents the soil eco-geochemical baseline with the soils of alluvial plains in eastern China and by using practical methods of experimental study and provides the information of the soil granularity and material composition related to the baseline. Further study indicates that the features of the soil material composition macroscopically control the regional distribution characteristics of the soil eco-geochemical baseline.

Abstract:Abstract：The grain sizes of sediments were measured and their distribution and parameters were analyzed through high-resolution sampling of the Jiangling section of the Jianghan plain and by using a Mastersize 2000 laser analyzer, and the paleoclimatic significance of the grain sizes in the area is discussed on the basis of the aforesaid analysis, combined with the sporopollen and lithologic data. The results show that coarse grains evidently increase in the sediments deposited in a warm-moist climate and decreased in a cold-dry climate. By comparison with the neighboring areas, the paleoclimatic change in the Jiangling area since 9 000 a B.P. revealed by the grain sizes of sediments is consistent with the results of study of other indicators in neighboring area in China.

Abstract:Abstract：On the basis of relevant data from multi-target regional geochemical surveys in Jiangsu province, this paper presents the results of the latest study of the distribution of phosphorus in topsoil in the study areas and discusses the in-depth study of the results of the investigation and applied problems. The following has been preliminarily found: total phosphorus is of very uneven distribution in topsoil of the province and its content is very high on the surface; volcanic ash soil originating from basic rocks, fluvio-aquic soil and salinized soil are three major P-rich soil types in the province; the Olsen-P distribution is not completely controlled by total P and the Olsen-P concentration is >5 mg/kg in >85% of the topsoil in the province; the deficiency of Olsen-P is markedly superior to that of total P in topsoil. Data comparison indicates that: the land use pattern can directly affect the distribution of Olsen-P in topsoil; the Olsen-P content in the topsoil of grassland, shoals and forest is notably lower than that in others cultivated land; and regression analysis indicates that there is a pronounced positive correlation between total P and Olsen-P in topsoil samples from local places.

Abstract:Abstract：On the basis of the 1∶50,000 agro-geological survey of the Xinfeng County Sheet, the neutron activation analysis was used to analyze eight rare earth elements (REE) (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) in fruit and leaf samples of three navel orange varieties from Anxi, Datang, Xiniu and Tongyi. This paper deals with the abundances, distribution patterns and manikin absorption of REE in navel orange fruit and leaf and their soils and parent rocks and discusses the relationship between REE and the quality of navel orange.

Abstract:Abstract：In the Yarlung Zangbo Great Canyon area, endemic and massive diseases of skeletal growth and development seriously affect the health of the residents and economic and social development. China Geology Survey has carried out regional geochemical survey of the Bomi and Mêdog sheets in the interior of the Yarlung Zangbo Great Canyon. The results indicate the following environmental geochemical characteristics: the vital elements Fe, P, Ca, Mg, Mn, Co and Zn are lower than their average values of stream sediments in China; the elements Cu, Mo, Cr, V and Ni are much lower. Toxicity elements Ba, Be, Sr, Li are on the high side. U Th are much higher; the poisonous elements Ba, Be, Sr and Li are higher; U and Th are Sr/CaO and Ba/CaO are disproportional. The occurrence of endemic diseases is closely related to the inferior environmental geochemical quality. Research also shows that large-scale material exchange and special geochemical landscapes resulting from plate movement in the great canyon area are the deep-seated causes for the inferior quality of the geochemical environment and occurrence of endemic diseases in the Yarlung Zangbo Great Canyon.noticeably higher and P/F,

Abstract:Abstract：The seismic inversion, which is one of the effective techniques for searching for sublle oil/gas traps, can enhance the resolution of seismic data greatly and extract abundant lithological and physical information involved in seismic data to the maximum. Simulated annealing wave impedance inversion pursues the comprehensive optimal solution widely in the space scope of the model, which can enhance the resolution of the inversion section markedly. The lithological reservoirs in the Dainan Formation in the Caozhuang area, Gaoyou subbasin, Subei basin, were predicted in detail by the ISIS3D simulated annealing wave impedance inversion technique. The results better describe the plan distribution characteristics of sands of three main lithological reservoirs in the Dainan Formation.