Abstract:Abstract：The study and discovery of more ore-forming environments and rock formations are conducive to expanding the exploratory field and enhancing the ore prospecting efficiency. Based on the regional metallogenic features of China, the author proposes some ore-forming environments that we should pay more attention to recently. Major features of regional metallogeny of China are as follows：① many ore deposits are concentrated on the margins of the old land；② multi-stage mineralization is well developed；③ superimposition and modification of mineralization are pronounced；④ hydrothermal ore deposits are abundant and diverse；⑤ organic mineralization and inorganic mineralization are combined；⑥ conditions for changes and preservation after the formation of ore deposits are complex.The ore-forming geological environments and rock formations which have high ore potential and in which some findings may be made include：① black shale series； ② melanocratic rock series,；③ composite sedimentary basins；④compounding of ancient lake basins and tectono-magmatic belts；⑤ multiple forms of superimposition mineralization； ⑥ time and space of transition of tectonic systems,；⑦ ore potential of geochemical blocks,；⑧ exploration of deep ore deposits and vertical zoning of mineralization. At last the author suggests some methods and ways to discover new ore deposits in China.

Abstract:Abstract：The early Precambrian stratigraphic system in the Daqingshan-Wulashan area is reconstructed based on recent regional geological survey. A Meidaizhao Group-complex is eslatlished and classified as the Paleoproterozoic. The high-grade metamorphic rocks in the area are regrouped, i.e. the granulite sequence is subdivided into two formation complexes, which are merged into the Sanggan Group-complex, and the Wulashan Group-complex is subdivided into two subgroup-complex, a lower subgroup complex. and an upper subgroup complex.The former is known as the gneiss sequence and the latter is equivalent to the Jining Group, a khondalite sequence. The major structural patterns of the high-grade terrain in the area are characterized by dome structures and fold groups between the domes (simply called ｀dome-fold＇ structures). It is suggested that the large-scale ledding detachment system is a key factor for determining the spatial distrilution,composition and interrelations of high-grade metamorphic rocks.The new ways and methods of estallishing lithostatigraphic systems in high-grade metamorphic terrains are proposed in the paper.

Abstract:Abstract：There are complicated folds in Paleozoic-Mesozoic sedimentary strata in the Xiluodu area along the Jinsha River. The structure resulted from superposition of three phases of folds during the Himalayan movement. The main modes of the superposition of the folds are ridden folding, shifted folding, non-sequent folding and refolding. Large-scale geological mapping and structural analysis indicate that the third-phase fold—Qingkou compound fold—constitutes a subsurface watershed, which is a barrier wall in the possible leakage path from the Xiluodu hydropower station reservoir head to the lower reaches of the Jinshan River, where karst pipe-type seepage is impossible to occur. The first determination and study of the third-phase fold in the area have great significance for the study of the leakage of the head of the huge Xiluodu hydropower station reservoir.

Abstract:Abstract：There are several structural layers in the Qiangtang basin owing to multi-stage tectonic movements, and these structural layers show different features of deformation. Some small and tight overturned folds are developed in the Triassic structural layers, and large broad anticlines and synclines or compound anticlines and synclines occur in the Jurassic structural layers. Compared with the above, Cretaceous-Neogene structural layers mostly occur in synclinal cores or anticlinal limbs, forming very broad folds. Folds are mainly of E-W trend, and from older to younger folds formed by different structural layers change from tight to broad and show the features of continuous and progressive superimposed deformation. All these show that amalgamation and compression of plates during different periods were the main forcing of the deformation. In addition, basal faults and basal uplift-depression controlled and affected the distribution and deformation of the folds to a certain extent.

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.

Abstract:Abstract：The Nanshanping anticline, located in the center of the Yangtze plate, is a destroyed ancient oil accumulation. The upper Sinian in the core of the anticline contains large amount of bitumen. Based on an analysis of the sequence of strata, the authors propose that the Sinian to Middle Triassic was a period of paleo-uplift development, which may be further divided into the Sinian embryonic paleo-uplift stage, Early Paleozoic paleo-uplift conservation stage and Late Paleozoic to Middle Triassic paleo-uplift development stage. Analysis of modification suggests that the period from the Late Triassic to Cenezoic was a period of the development of faults and folds, which may be subdivided into the stage of Late Triassic-Middle Jurassic broad anticline development, stage of fault propagation and anticline development in the II phase of the Yanshanian movement and stage of late Yanshanian and Himalayan anticline modification. The Nanshanping ancient oil accumulation takes dolomitite of the upper Sinian Dengying Formation as the reservoir and black carbonaceous mudstone and stone coals of the overlying Lower Cambrian Niutitang Formation as source rocks. Oil and gas were accumulated in the paleo-uplift from Silurian to Middle Triassic. The Late Triassic and Middle Jurassic witnessed the redistribution and formation of the Nanshanping ancient oil accumulation. Later the ancient oil accumulation was destroyed.

Abstract:Abstract： The Shangnan granitoid and Diaozhuang granitoid on the north side of the Shangdan fault zone in the East Qinling belong to the calc-alkaline series and have the characteristics of island-arc granitoids. These rocks have higher Na2O（3.54%～5.52%） and lower K2O（0.75%～3.46%）, Na2O/ K2O = 1.09～6.16，SiO2＞56%（61.84%～74.57 %），Al2O3≥15%（13.41%～19.01%），MgO＜3%（0.65%～2.41%） and Mg#=43.87～66.12. They are notably depleted in Y with Y＜18×10-6, ranging from 1.90×10-6 to 18.4×10-6, and Yb with Yb＜1.9×10-6, ranging from 0.27×10-6 to 2.27×10-6, and enriched in Sr with Sr＞400×10-6，ranging from 350×10-6 to 830×10-6. Sr/Y ratios vary from 25.29 to 216.71，being ＞20～40. The granitoid rocks are enrich in LREE and depleted in HREE with most La/Yb＞20 （47.60～110.93） and （La/Yb）N＞20（32.09～99.13），and exhibit no Eu anomaly or only weak positive Eu anomaly. The large ion lithophilous elements（Rb, Ba, Th and Sr） are relatively enriched and high field strenth elements（Nb, Ta, Zr, Hf and Ti）are relatively depleted. The isotopic composition indicates that the 143Nd/144Nd ratios（0.512127～0.512134）of the granitoids are very similar to those（0.512651～0.512917） of the Songshugou ophiolite in the Shangnan area and that their εNd（t=889Ma） values are positive（+1.23 to +2.51）, implying that the source rocks of these granitoids are dominated by MORB. These geochemical characteristics are similar to those of adakitic rocks formed by partial melting of MORB related to subduction of oceanic crust, suggesting that these Neoproterozoic granitoids in this study area might be adakitic rocks. The adakitic granitoids in the Shangdan area may be the result of the northword subduction of the ancient ocean basin (ancient Qinling ocean), represented by the Songshugou ophiolite and the Heihe N-MORB type basalt, along the Shangdan tectonic zone during the Neoproterozoic. This slab subduction of oceanic crust led to the partial melting of MORB rocks and the formation of the adakitic granitoids in the Shangdan area.

Abstract:Abstract：According to detailed mapping in the Jinping area on the southern edge of the Su-Lu orogen, it is affirmed that the boundary between the ultrahigh-pressure metamorphic belt and high-pressure metamorphic belt is a ductile shear zone. No regional folds occur in the area, but instead, as the Jushan granitic gneiss and metavolcanic rocks of the Yuntai Group-complex form a competent rock layer, an incompetent rock layer was formed by metasedimentary rocks of the Jinping Group-complex； they combine to form a “layer cake”-style rock assemblage. In the Indosinian period, dextral shear gave rise to heterogeneous shear deformation； as a result, a rootless tongue-like fold of the Jushan granitic gneiss was formed. It is about 10 km long from north to south and about 5 km wide. The material movement is south-vergent in the Jinping area.

Abstract:Abstract：According to the tectonic deformation features of a medium- and lower-grade metamorphic series in the Huzhong area, Da Hinggan Mountains, five tectonic slices are distinguished. They underwent two phases of tectonic deformation. In the early phase extension changed the basic structure of the original strata. In the late phase, in the contractional regime strong thrusting-compression resulted in displacement and overlapping of tectonic slices and thus made the strata wide non-Smith. According to the deformation features of different rock associations, eight tectonostratigraphic types are recognized. On that basis, combined with the characteristics of rock associations, the authors establish the tectonostratigraphic units-the Jixianggou formation-complex and Dawangzi formation-complex. The two formation-complexes are called the Wolegen Group-complex.

Abstract:Abstract：The Xi Ulanbulang hypersthene-plagioclase granulite in central Inner Mongolia is regarded as an old granitic intrusion separated from the Caledonian plagiogranite and Variscan granodiorte, as has been determined by regional surveys of the 1∶50 000 and 1∶250 000 Shilanhada Sheet and Bayan Obo sheet. Single-zircon U-Pb dating of the hypersthene-plagioclase granulite gave discordia and concordia upper and lower intercept ages of （2 511.4±4.9） Ma and （818±159） Ma respectively. These ages, combined with the results of regional survey, suggest that the former age represents the age of emplacement of the older granitic intrusion； while the latter represents the age of the superimposed deformational-metamorphic thermal event in the late stage .The two ages give direct evidence for crustal evolution in the Central Daqing Mountains.

Abstract:Abstract：Many Au (Ag)-polymetallic ore deposits have been discovered in the volcanic rock series of the Xiong’er Group on the south margin of the North China plate. However, there are many different explainations for the genetic mechanism of these deposits. Based on a systematic study of the geological characteristics of these deposits, features and genesis of hydrothermal ore fluids, mineralized and alterated host rocks, the authors propose the new views that the volcanic hydrothermal fluids after the Xiong’er volcanic activity is the main factor controlling the formation of the Au (Ag)-polymetallic ore deposits, and that the major ore-forming processes are depostion and cavity filling of hydrothermal fluids. In addition, the authors also suggest that the main mineralization stage is the late phase of the Xiong’er volcanic activity.

Abstract:Abstract：Global correlation indicates that there occur three relatively complete magmatic-hydrothermal minerogenic series in the Emeishan flood basalt province. The outpouring conduits for fissure eruption of the Emeishan basalt was controlled by the discontinuity of the lithospheres revealed by the geochemical boundary. The preservation of a complete rock association of paleovolcanic vent facies in these districts provides an important clue to mineral exploration. There were three magmatic fractionation trends in magma chambers： sulfur-poor, low-orygen fugacity magma, sulfur-poor, high-oxygen fugacity magma and sulfur-rich magma, which produced three magmatic minerogenic series（Cu-Ni-PGE, Cu-Ag-Pd and Fe-Ti-V）. Synvolcanic-hydrothermal activity gave rise to copper minerogenic series from low greenschist and prehnite to zeolite facies (from 400℃ to100℃). Hydrothermal fluids of different compositions controlled the formation of native copper, copper oxides and copper sulfides. Comparison of the vitrinite reflectance R0 indicates that bitumen that played an important role in controlling native copper precipitation was derived from hydrothermal pyrolysis of organic matter at the P2-T1 boundary and that organic matter was at the mature stage for oil genesis. Therefore, a package exploration for Cu, Ni, Pt-Pd and petroleum can be launched, as is the case with the Midcontinent Rift in Michigan, United States.

Abstract:Abstract: The Garzê-Litang fault belt has experienced a series of complex evolutionary processes since the Paleozoic and is a large-scale, structurally complex ophiolitic mélange belt that has been strongly reworked and dismembered by overthrusting and sinistral strike-slip shear during the Cenozoic Himalayan orogeny. Gold mineralization is mainly associated with overthrusting, strike-slip motion of the fault belt and post-mineralization supergene oxidationn during the Himalayan orogeny. Hydrothermal activity is widely developed along the fault belt, showing that modern hydrothermal mineralization is just taking place. The study of the regularity of the Himalayan tectonic movement is of great significance for mineral prospecting in the study area.

Abstract:Abstract：The Ordovician buried hills in the Bachu rise, Tarim basin, has good gas prospecs. The Hetianhe gas field and well Shan 1 gas accumulation were discovered in this area. The area has good hydrocarbon source rocks, a well-matched association of reservoir and cap rocks and a very large trap so；it is an advantageous area for petroleum exploration. According to an integrated study of the characteristics of the Hetianhe gas field and well Shan 1 gas accumulation, the authors suggest that the formation of gas accumulations was principally controlled by hydrocarbon source rocks, faults, unconformity and karstification. So long as the four controlling factors can match well, large gas accumulations can be formed. Based on this study, combined with exploration practice in carbonate gas accumulations both at home and abroad, the distribution characteristics of carbonate gas accumulations are summarized as follows: they are distributed along paleo-uplifts, along faults, along unconformities and near hydrocarbon source rocks. According to the principal controlling factors and distributing characteristics of buried hill gas accumulations, in the study area the zone south and west of the pinch-out line of the Silurian and Ordovician, the line of wells Shan 1 and Macan 1 and the Selibuya fault zone should be chosen as the chief exploration targets. In addition, a systematic study should be carried out on the Kalashayi fault zone where karst is well developed.

Abstract:Abstract： There are various environmental-geological problems in the Nansi Lake drainage area. Problems including water pollution, geological disasters of mines, environmental abnormity of groundwater, siltation of Nansi Lake and endemic diseases are discussed. Coal mining has an active influence on the evolution of Nansi Lake. The lake and main rivers flowing into the lake have been highly polluted under the influence of anthropogenic activities. Environmental geological hazards caused by development of local coal resources are very serious in the drainage area. The surface collapse area in the drainage area is up to 112.395 km2. The amount of various solid waste totals to 64.1268 million tons, covering over 595.13 ha. Groundwater resources in the mine district have been destroyed badly due to a large amount of mine drainage. Endemic fluorosis and chronic keshan disease are the main endimic diseases due to the high concentration of fluorine in shallow-layer groundwater and lack in selenium in food and water respectively. On the basis of a comprehensive analysis of these environment-geological problems in the drainage area, measures for environmental control have been put forward in detail in the paper and various influencing factors should be considered in treating environment-geological problems in this area.

Abstract:Abstract：The Daya Bay is a big bay in eastern of Guangdong, adjoining Shenzhen and Hongkong. The current state and tendency of its environment attract attention of many researchers. The heavy metallic elements Hg, As, Cd, Cu, Pb, Cr and Zn in 45 samples of surface sediments, 85 samples from one drilling hole and 2 cores in the Daya Bay were analysed. Based on the distribution of heavy metals, the substrate environment was quantitatively assessed. The results are as follows. (1) The pollution indices Pi of Hg, As and Cu are all <1.0, suggesting that the entire bay is not polluted by these factors. (2) Some pollution indexes of Cd, Zn, Pb and Cr are > 1.0, suggesting that the bay is polluted by these factors to different degrees, of which the pollution index of Pb changes from 0.83 to 2.25, indicating low to moderate pollution and on the whole slight pollution; the index of Zn changes greatly from 0.25 to 2.63, generally showing slight pollution; the index changes from 0.50 to 1.78, showing low to slight pollution; the index of Cr changes from 0.49 to 1.90, showing low to slight pollution. (3) The synthetic pollution index (SQI) varies from 1.08 to 2.21, with a mean of 1.37, suggesting that the area is polluted by heavy metals to different degrees, generally showing slight pollution. The most serious pollution appears in the Fanhe Harbor, with most SQI values＞1.5, and the second most serious pollution appears in the sea area near the Central islands. The mouth of the bay and the sea area off the coast from Aotou to Xiayong are less polluted. The contents of heavy metals on the surface have no marked tendency of increase, as shown from the distribution of the heavy metal contents of samples from the drilling hole and cores.

Abstract:Abstract： An integrated analysis has been performed of the climatic carriers such as magnetic susceptibility, grain-size, CaCO3 and TOC in the Minhe loess on the northeast margin of the Qinghai-Tibet Platean. The time interval of 1.90 to 0.70 Ma BP for the loess on the northeast edge of the Qinghai-Tibet Platean can be subdivided into seven climatic stages. Climatic analysis of the Minhe loess shows the following： before 1.10 Ma BP (layer L11 of the Minhe loess), the climatic difference was small and the winter monsoon and summer monsoon were not strong, with only weak antagonism, and loess and paleosol were less developed and relatively thin; by contrast, after 1.10 Ma BP, the antagonism between the winter monsoon and summer monsoon was enhanced rapidly, and the climatic difference became pronounced. A comparison between the isotope records of the Minhe loess and other areas and the oxygen-isotope records of deep-sea sediments indicates that paleosol layers S8, S9 and S10 of the Minhe loess correspond separately to deep-sea oxygen stages 21 and 23 and 25 better, while loess layers L9 and L10 and L11 are separately coincident with stages 22 and 24 and 26. The correlation between loess records below loess layer L11 and deep-sea oxygen-isotope records is not very pronounced. In addition, the high-resolution climatic records of the Minhe loess are well coupled with the staged uplift of the Qinghai-Tibet Plateau.

Abstract:Abstract：Lanzhou is located in the western part of the Loess Plateau in northwestern China. The factors of urban pollution are mainly amog (smoke and dust in air), fine sand flying up in air and secondary dust (ground dust), as well as dispersion of solid waste and sewage irrigation. The main polluting elements are Hg, Sb, Pb, Be, As, Cd and F. The characteristics of pollution of elements dominated by heavy metals are as follows：(1) the pollution degree is closely related to the population density and flux of people; (2) the pollution degree in the city district where the population is concentrated and the commerce is well developed is higher than that where the population is less dense and industries are more concentrated; (3) for industrial pollution the pollution degree of the heavy industry is higher than that of the light industry; (4) for agricultural pollution the pollution degree in sewage irrigation areas is higher than that in non-sewage irrigation areas； and (5) heavy metals in pollutants increase with fining granulation of grains and then their harming degree also increases. In the evaluation of the pollution degree, in addition to the pollution index, the areal metal quantity and background index of exploration geochemistry are also introduced, which makes the evaluation have more regionalized and comprehensive effects.