Abstract:Abstract：Pt-Pd-Cu ore-bearing formations in eastern Yunnan include the black shale ore-bearing formation and basalt ore-bearing formation. The authors mainly made a systematic study of the geochemical characteristics of the Proterozoic Kunyang Group, Lower Cambrian black rock series and Permian Emeishan basalt. Study shows the followings: (a) the black rock series of the Proterozoic Kunyang Group is characterized by significant enrichment of As and B (K≥5) and enrichment of Sb, Pd, Mo, Ag, U, Pt, V, Zn, W and Cu (K≥1.2); (b) the Lower Cambrian black rock series is characterized by significant enrichment of Mo, Ag, U, As, V, B, Pd and Sb (K≥5) and enrichment of Pt, Pb, Zn, W, Cu and Ni (K≥1.2); (c) the Permian Emeishan basalt is characterized by significant enrichment of Pt and Pd (K≥5) and enrichment of Au, Ag, Cu, Zn, Sb, B, U and V (K≥1.2). In conclusion, the black rock formation and Permian Emeishan basalt distributed at different horizons in the study area form the primary ore source bed of noble metal elements (Pt, Pd, Ag, Au etc.) and nonferrous metal elements (Cu, Mo, V etc.) in eastern Yunnan Province. The areas that are best coupled by the above-mentioned regional ore-forming factors may be regarded as the potential areas where nontraditional ore deposits of noble metals(Pt, Pd, Ag, Au etc.) and nonferrous metals (Cu, Mo, V etc.) possibly occur.

Abstract:Abstract： Simulation of gravity anomaly at the Liu’an-Daye wide-angle reflection profile transecting the Dabie orogenic belt shows that the gravity anomaly produced by the density profile obtained by conversion of the seismic velocity from wide-angle reflections is a gravity high, which reflects that the Dabie Mountains area is a dome. This result is quite different from a gravity low determined by the field gravity measurements. The gravity anomaly can be well simulated only by placing a huge low-density body from the surface to the Moho at the boundary between the North and the South Dabie Mountains, at the root of the Dabie Mountains. This low-density should be a nearly NW-trending granite belt. Its location is in good agreement with that of the Shizhen transparent seismic reflection belt but it is far wider than the latter. The fitting of the gravity curve further suggests that after collision between the North China block and Yangtze block an extensional period occurred in the Dabie area during the Cretaceous, and meanwhile, the Dabie dome formed, accompanied by extensive intrusion of granite, and ultrahigh-pressure metamorphic rocks were exhumed to the surface. This study shows that it is necessary to combine seismic reflection profiling, wide-angle seismic reflection profiling and gravity survey to make an integrated interpretation.

Abstract:Abstract： Three groups of apatite fission-track ages indicate three tectonic uplift events： the uplift of the Altyn Tagh block at the end of the Cretaceous (69.5±2.9 Ma BP) and the uplifts of the front of the Kunlun Mountains and rear zone of the Kunlun Mountains (on the northern margin of the plateau region) in the late Pliocene (4.2±0.8 Ma BP and 3.9±0.6 Ma BP) and in the middle Early Pleistocene (1.66±0.31 Ma BP). The paleo-altitudes of the apatite fission-track samples are calculated on the basis of the paleo-burial depths of the samples and paleo-altitudes of the surface inferred according previous relevant data, and then the absolute tectonic uplift amount is calculated, which is equivalent to the altitude difference and the absolute rate of tectonic uplift is equivalent to the ratio of the absolute uplift amount to the difference of apatite fission-track ages. The results of the calculation are as follows：the northern margin of the Altyn Tagh has risen 4 940 m since 69 Ma BP, with an average uplift rate of 0.072 mm/a; the front zone of the Kunlun Mountains has risen 1 380 m from 4.15 to 1.66 Ma BP, with an average uplift rate of 0.55mm/a, and risen 4 140 m since 1.66 Ma BP, with an average uplift rate of 2.49 mm/a; the rear zone of the Kunlun Mountains has risen 1 500 m from 3.85 to 1.66 Ma BP, with an average uplift rate of 0.70 mm/a, and it has risen 5 140 m since 1.66 Ma BP, with an average uplift rate of 3.19 mm/a. In combination with the relevant terrace features and ages, it may be estimated that the average uplift rate of the rear zone of the Kunlun Mountains may have reached 11 mm/a since the end of the late Pleistocene (21 ka BP). The rear zone of the Kunlun Mountains may have risen 1 120 m relative to the front zone of the Kunlun Mountains since 4 Ma BP and the ratio of the average uplift rates of the two zones is about 1.2.

Abstract:Abstract: Located in the Nanping-Ninghua tectono-magmatic belt, the Gaiyang Group is composed of a low-grade metavolcanic series, which is divided into the Louqian Formation, Sanxizhai Formation and Longtou Formation by Huang Quan-zhen et al., and its age is assigned to the late Sinian. Through 1:50 000 detailed regional geological survey and reconstruction of the old volcanic structure, the Gaiyang Group is considered to be the product of volcanic activity in the same structural setting according to the stratigraphic sequence, rock association and volcanism. From the early stage to late stage, the rocks make up a complete volcanic-sedimentary cycle from strong to weak eruption. So the authors suggest that the Gaiyang Group may be divided into the Louqian Formation and Longtou Formation, and according to new isotopic data, the ages of the Louqian Formation and Longtou Formation should be assigned to the Nanhua period and Sinian period respectively.

Abstract:Abstract：The study of nature of the protoliths of metamorphic rocks in the Xingzi Group and their tectonic setting shows that the protoliths of mica schist, quartz schist and granulitite (leptite) in metamorphic rocks of the Xingzi Group are sedimentary rocks. Among other things, the protolith of mica schist is claystone, those of quartz schist and granulitite are graywacke or subgraywacke and those of amphibolite, hornblende schist and garnet amphibolite are basic volcanic rocks. Discrimination of the tectonic setting of metasedimentary rocks indicates that the Xingzi Group formed on active continental margins. Metabasic volcanic rocks are a transitional type between island-arc tholeiite and mid-oceanic tholeiite. They were formed in extensional basins.

Abstract:Abstract： The Duolun ring image is found on the border of southeastern Inner Mongolia and Hebei Province. The image is complete, with a diameter of ca. 70 km. There are mainly two views about the genesis of the ring, meteorite impact and Mesozoic paleovolcanic edifice. Through a systematical 1：50000 regional geological survey, the authors found that the trough of the ring is mainly covered by Quaternary deposits, with Pliocene basalts exposed locally. Data of drilling and abnormal magnetic variation show that large amounts of Cretaceous trachyandesite and Pliocene basalt are hidden in the subsurface. Regional faults of all directions are developed at the edges of the ring. Both inside and outside the ring there occur Precambrian metamorphic rocks, Meso- and Neoproterozoic and Lower Permian strata and Mesozoic volcanic-sedimentary rocks. Geologic bodies of different ages are intact with a clear stratigraphic succession. Mesozoic volcanic rocks are the product of a number of eruptions of central or fissure-central types. Therefore, the authors conclude that the Duolun ring may be the result of combined deep-seated magmatism and regional faulting.

Abstract:Abstract：This paper briefly introduces the distribution, sedimentary formations, sedimentary environment, biotic province and tectonic deformation of the Triassic System, as well as its deformation difference from the adjacent geological bodies in the western Qinling. On that basis it discusses the evolutionary history of the study region. This region evolved quickly from the Yangtze-type neritic carbonate rocks in the stable environment to the Tethyan-type very thick abyssal flysch sediments during the short Middle Triassic geological evolution. It also discusses the tectonic features of the Tethyan taphrogeosyncline during the evolution from its opening and deposition through closing and stopping of deposition to rapid closing and folding. Finally the paper sums up the Triassic basin evolution pattern.

Abstract:Abstract：The Lower Ordovician reef-bearing strata in the middle Yangtze platform may be divided into four II-type depositional sequences based on the principle and method of outcrop sequence stratigraphy. According to the characteristics of the systems tracts and depositional dynamic mechanism of these sequences and the controlling effects of sea level changes on the sedimentation, organism migration, bioreefs and environment, it is held that there occurred four sea level change cycles during the formation of the reef-bearing sequences in the study area： the first one occurred from the early to middle Lianghekouan age, the second one from the late Lianghekouan age to early Daobaowanian age, the third one from the early to late Daobaowanian age, and the last one from the early to middle Dawanian age. In the second cycle three subcycles are distinguished： the first subcycle occurred in the Second Member (Oolite Member) of the Fenxiang Formation, the second one in the Third Member (Alternatation Member) of the Fenxiang Formation, and the third one in the Fourth Member (Intercalation Member) of the Fenxiang Formation. Three keep-up carbonate systems and one lag carbonate depositional system are recognized. The reefs of the Fenxiang and Honghuayuan Formations formed in the highstand phase. Because of the occurrence of multiple subcycles in the process of sea level change, the reefs in the study area are characterized by the small thickness, small scale, large number and wide distribution.

Abstract:Abstract：The Middle Jurassic Formation in the Pingquan basin is a very thick sequence of red detrital rocks formed under inland dry climatic conditions.From below upward the sequence can be divided into four lithological members;the first member at the base is mainly marked by an alluvial fan depositional system,the second member is a lake depositional system,the third member is a river system,and the fourth member is a composite alluvial fan and river system.The above filling sequence reflects that at the time of deposition of the Tuchengzi Formation the basin experienced three evolutionary stages,i.e.:incipient subsidence,lake basin spreading and basin contraction.

Abstract:Abstract：The Meso-Cenozoic basins along the Yangtze River in Anhui Province are located at the southern margin of the Dabie orogen. They are overlapped basins formed by compression and then by extension. These basins are ideal sites for the study of the coupling between the uplift of the Dabie orogen and the subsidence of the basins in the middle-lower Yangtze River region. In the Early Mesozoic, the Dabie Mountains area is a collisional orogen between the South and North China continental blocks. The South China continental crust was subducted to great depths and underwent ultrahigh-pressure metamorphism. Then the ultrahigh-pressure metamorphic rocks were exhumed progressively to the surface. The depressions along the Yangtze River is of foreland basin nature, which are filled with Late Triassic-Middle Jurassic molasses. In the Late Mesozoic, in the wholesale extensional setting in eastern China, the Dabie metamorphic belt was entirely exhumed and was in a regime of metamorphic core complex. On the other hand, the depressions along the Yangtze River is of rift basin nature, which are filled by Late Jurassic to Early Cretaceous and Late Cretaceous to Paleocene red clastic sequences. These clastic sequences were formed as a result of the coupling of isostatic uplift and extensional rifting.

Abstract:Abstract：There occurs a suite of argillite in the lower plate of the Daqingshan thrust nappe structure. It formed by dynamic metamorphism caused by thrust deformation of Permian mudstone, silty mudstone, siltstone and fine sandstone. A set of penetrative plate cleavages are developed in the rock. The identification of rock thin sections shows that syntectonic neogenic minerals such as sericite, muscovite and chlorite are formed along the cleavage planes. Dating of the syntectonic neogenic muscovite by the laser microprobe 40Ar/39Ar method yielded a 40Ar/39Ar isochron age of 121.6±1.6 Ma. Field geological evidence suggests that two phases of thrust deformation occurred in the Indosinian and late Yanshanian periods respectively in the Daqingshang region. The 40Ar/39Ar isochron age of 121.6±1.6 Ma represents the age of the late Yanshanian thrust deformation event.

Abstract:Abstract：The Manzhouli area is an important metallogenic province of nonferrous and noble metals. The regional strata consist mainly of Mesozoic continental volcano-sedimentary formations. The Jiawula, Chaganbulagen and Eren Tolgoi Ag- (Pb-Zn) deposits all occur on the bottom of the strata. Previously there were disputes on the age of the host strata. The authors have further studied the characteristics of the host strata in the three Ag- (Pb-Zn) districts and in the Bayan Haolei Ag-polymetallic mineralization district and the strata of the Kanzijing section which plays a very important role in the stratigraphic division in the area. The results of the study indicate that the strata hosting the Ag- (Pb-Zn) deposits in the area are notably differerent from their overlying Late Jurassic Early Cretaceous strata in respect of the rock association, stratigraphic sequence and geochemistry. The fossils discovered in the host strata and new geological research results in the area suggest that the age of the strata hosting the Ag- (Pb-Zn) deposits in the area is Late Triassic-Early Jurassic.

Abstract:Abstract：Porphyry copper deposits in the world are confined mainly to the Mesozoic-Cenozoic circum-Pacific belt and Paleo-Tethys belt and Paleozoic Central Asia-Mongolian belt, where convergent plates are developed. Tibet is one of the best developed regions of convergent plates in the world, in which the Jinshajiang, Yarlung Zangbo and Nujiang-Bangong Co suture zones lie. These suture zones have a long history of oceanic plate subduction and continent-continent collision with well-developed tectonomagmatic activity marked by widespread plutonic and high-level granite-porphyry, which is favorable to the formation of porphyry copper (-gold) deposits and other related deposits. By referring to the experiences in assessment of porphyry copper deposits at home and abroad in recent years, this paper looks forward to the prospects of porphyry copper deposits in Tibet.

Abstract:Abstract：Very thick salt rocks are developed in the Puwei subdepression of the Dongpu depression. To ascertain their development pattern and genesis is of great significance for the study of the regional geology and oil and gas exploration. Using the basic theory and method of high-resolution sequence stratigraphy, on the basis of an integrated analysis of the cores, logs and seismic data, combined with an analysis of the basin structure and stratigraphy, seven salt rhythmic successions are recognized in the Paleogene Shahejie Formation in the study area, of which 3 are of the first order and 4 are of the second order. The development and distribution pattern of each salt rhythmic succession is analyzed. Geochemical and paleontological analyses indicate that the Eocene climate in the area had high-frequency dry-moist change, that the source of salt rocks was mainly seawater in the marine flooding period, and that salt rocks in the high-frequency sequences formed by evaporation of water at depths during the dry lowstand phase.

Abstract:Abstract：The Tahe oilfield in the northern part of the Tarim basin is China’s first largest Paleozoic oilfield. It was discovered from 1990 to 1997. By 2002 a petroleum-bearing area of ~ 1000 km2 was controlled, with explored reserves of 250 million tons. Its discovery has great significance for guiding the search for this type of oilfield in the Tarim basin and even the whole of China. The author thinks that sediments in the Tarim oilfield are depression-type marine carbonate rocks in the ancient cratonic basin. It is located in a cratonic paleo-uplift-Shaya uplift, where faults and regional unconformities are very well developed, which are favorable for the concentration of oil and gas. As it adjoins the Manjiar oil-generating depression on the south, it is a good vector area for oil and gas migration. Two Hercynian tectonic movements resulted in the development of Ordovician paleokarst, thus giving rise to reservoirs with good pores, caves and fissures. Moreover, the occurrence of four phases of oil and gas migration and accumulation is the basic condition for the formation of a large oil/gas field. This oilfield is expected to become an exceedingly large oilfield with oil reserves of 800 million to 1 billion tons.

Abstract:Abstract：Supergene deformation structure, whose mechanism is different from that of the endokinetic deformation structure, in marly limestone in the Three-Gorges region forms by karst dissolution in special geological, geomorphological and climatic conditions, and while endokinetic deformation is superimposed by supergene deformation, the structure would become very complex. Supergene deformation structure may fall into the continuous deformation structure type, discontinuous deformation structure type and transitional deformation structure type, of which the first type includes flying goose-shaped folds and bending layers, the second type includes the close-spaced joint zone and normal fault by dissolution, and the third type includes boudin structure by dissolution and turning-around blocks. They are widespread in the Three-Gorges region and form by dissolution of marly limestone. The process of supergene deformation is also the process of ground deformation and destruction. Many geohazards occurred frequently in the Three-Gorges region are related to the development of supergene deformation structure. Therefore the most effective measure to control geohazards is to keep water from infiltrating into the ground.

Abstract:Abstract：The Kaschin-Beck disease is an endemic disease widespread in China. It prevails in the Aba Prefecture, Sichuan Province, and especially is seriously prevalent in the Bobso area, Zoigê. Through the study of the cause of the disease, characteristics of bioelements and element background values in the disease and non-disease areas by previous experts, the authors think that the cause of the Kaschin-Beck disease probably is due to the concentration of humic acid, lower values of Se, Mo, Cu and V and the lack of Ca resulting from antagonism of B, Sr and P on CaO. Meanwhile, through the element geochemical study of the soil and water in the "Pa" (lying on the ground) disease area in the 1:200 000 Neijiang Sheet, the authors think that the causes of the two diseases bear some similarities, which may corroborate the geochemical cause of such kind of endemic bone disease.

Abstract:Abstract：On the basis of the field survey and statistical analysis of a wealth of data about the fundamental geology, economic geology, environmental geology, tourism geology and agricultural (forestry) geology, and under the direction of the GIS technique, an integrated assessment of the ecological-geological pattern potential of exploitation and utilization of various resources in the forest shallow cover areas was carried out by using the semi-quantitative analysis and assessment method that combines the qualitative method with the quantitative one. Based on the study of the integrated assessment method of the ecological geology in forest shallow cover areas, the authors present a model for assessing the ecological geology of forest shallow cover area and determines the synthetic parameters, and moreover the types of ecological geology are also distinguished.