Abstract:Abstract: There existed some blocks (micro-plates) in the oceans between Australia and Asia in the Cenozoic, when some blocks were separated from the Australian plate and moved northward and collided and sutured with some blocks that were separated from the Eurasian plate. In this period small ocean basins such as the South China Sea, Sulu Sea, Celebes Sea and Andaman Sea formed as a result of block separation and seafloor spreading, and finally the present tectonic framework formed in the Great South China Sea area. After a study of the Cenozoic tectonic history of the Great South China Sea area, the authors believe that Cenozoic tectonic activities in the Great South China Sea were not only related to collision between the Indian Plate and Eurasian Plate but also to subduction of the Pacific Plate beneath the Eurasian Plate and were also affected by the northward movement of the Australian. Plate. In the South China Sea Basin there occurred two events of seafloor spreading in the Cenozoic. The first seafloor spreading, which was oriented in a NW-SE direction, occurred before 42-35 Ma BP under the influence of the southeastward mantle flow beneath the Eurasian continent caused by India-Eurasia collision. The first seafloor spreading gave rise to the Southwest Basin of the South China Sea. The second seafloor spreading took place before 32-17 Ma BP. As the Pacific plate was subducted beneath the Eurasian plate to 700 km depth, the SE-directed flow of the upper mantle of the Eurasian continent was blocked and then turned toward the south, thus causing N-S-trending seafloor spreading in the South China Sea area, i.e. the second seafloor spreading. The second seafloor spreading resulted in the formation of the Central Basin of the South China Sea. After the Cenozoic South China Sea Basin was produced, collision between the blocks and seafloor spreading continued in the Great South China Sea area, and under the compression of these northward blocks the south margin of the South China Sea, sediments in the area were deformed, thus producing the Wanan movement (at about 10 Ma BP) on the south margin of the South China Sea.

Abstract:Abstract： The Zhangbaling tectonic belt is a part of the Dabie orogenic belt and an outcrop area of the mid-upper crust of the belt. By using the combined tectonic and stratigraphic method to analyze the l∶50000 geological mapping data of the Zhangbaling area and make structural analysis of the typical cases, the following new ideas have been got： there is no boundary of strong tectonic movement between the Zhangbaling Group-complex (Pt2～3) and the Nanhuaan-Ordovician or strata above them, and as a component part of the Dabie orogenic belt, the group-complex underwent strong deformation； in the Indosinian-early Yanshanian there mainly occurred three phases of tectonic deformation, i.e. a series of WNW-and nearly E-W-trending tight congruous folds in the early stage, a ductile shear zone in the middle stage, and the mainly NNE-trending, broad folds accompanied by SE-vergent overthrusting in the late stage. The superimposition of the three phases of deformation formed the basic tectonic framework of the area. Folding and overthrusting (front sliding) took place in the mid-upper crust (include sedimentary cover) concomitantly with subduction of the Yangtze block beneath the North China block and their collision. The three phases of deformation represent a process of progressive deformation.

Abstract:Abstract：The complexity of the early-stage tectonic deformation in the Xileng Formation-complex in the Zhangbaling area, Anhui Province is mainly manifested by folds and ductile shear deformation closely related to folds. There are at least three stages of tectonic deformation in strata, of which F1 is NW-trending ductile shear folds at an outcrop scale, F2 is SSW-plunging flexural folds, and F3 is nearly E-W-trending broad folds. F1 and F2 combine to constrain the gross framework of the distrilution of the Xileng Group-complex . Microfabrics, especially the magnetic fabric features of rocks, prove that multi-stage tectonic deformation took place in the area. Two stages are most conspicuous, i.e. the early-stage horizontal shear and ensuing lateral extrusion. The paper focuses on the geometric features of the above-mentioned fold deformation and also analyzes its kinematics and dynamics.

Abstract:Abstract：The Baolun gold deposit, as one of the large gold deposits found in Hainan Province recently, is a structurally controlled, magmatic-hydrothermal gold deposit formed in the Indosinian. In the gold district there outcrop the Lower Silurian Tuolie Formation low-grade metamorphic series and Indosinian red clastic rocks, and in addition Indosinian granite is distributed on its northwest side. The NNE-trending Haogangling fault and the NNW-trending fracture zone in the hanging wall of the fault form the basic structural framework of the ore district. Magnetic fabric analysis indicates that： flattening deformation predominates in phyllite of the district； the principal compressive stress is oriented in a nearly E-W direction； the structural deformation was stronger before the mineralization thermal event and weaker after mineralization. The structural stress field in the mineralization stage is featured by E-W extension (the principal compressive stress was oriented in a N-S direction). The NNW-trending fracture zone is the main ore-hosting (ore-bearing) structure, which exerts an important controlling effect on the shape, attitude, scale and special distribution of the gold orebodies.

Abstract:Abstract： According to the rock composition, occurrence, textures, emplacement mechanism and geochemical characteristics, the Yanshanian granitoids in the Dabie UHP metamorphic belt may be classified into two major types： the high-K calc-alkaline series and the normal calc-alkaline series. The high-K calc-alkaline series is represented by the Datong rock body and the early-stage and main-stage Sikongshan rock bodies and composed lithologically of granodiorite-monzogranite. The chemical composition is characterized by SiO2 >56%, Al2O3≥14%, MgO <3%, high Sr and Ba contents, enrichment in LREE, strong depletion in HREE, high Sr/Y and La/Yb ratios (≥30 and ≥39, respectively), low Y(<18×10-6) and Yb (<1.9×10-6) contents, and indistinct Eu and Sr negative anomalies. These characteristics are similar to those of adakite. The normal calc-alkaline series is represented by the Yingshanjian rock body, consisting dominantly of monzogranite. It is characterized by high SiO2 (>70%), low Al2O3 (<14%), low Sr and Ba contents, low Sr/Y （<10） and La/Yb （<10） ratios, high Y (>18×10-6) and Yb (>1.9×10-6) contents, depletion in LREE, enrichment in HREE, and pronounced negative Sr and Eu anomalies. The high-K calc-alkaline granites might be derived by partial melting of the thickened lower crust, while the normal calc-alkalis granites probably originated by anatexis of the normal crust.

Abstract:Abstract：This paper introduces the main results obtained in mapping the ancient orogenic area in the northern segment of the Lüliang Mountains， Shanxi， with the slab method. By 1∶250 000 mapping， three important tectonic boundaries have been found， and on that basis three tectonic slabs have been defined. Each slab has a binary structure and three slabs overlap each other， suggesting strong crustal shortening， which proves the existence of the orogenic belt. The geological event that took place at 1850 Ma was convergence rather than breakup. The Lüliang orogeny resulted in real cratonization of the North China block. During the Lǚliang orogeny there occurred two types of ductile shear zones： I-type ductile shear zones occurred between slabs， and II-type ductile shear zones in the interior of a single slab. So it is necessary to distinguish them in geological maps.

Abstract:Abstract：The Qinling is a complex continental collisional orogenic belt resulting from long-continued， multi-stage development. This paper reports the results of isotopic analyses of the SHRIMP zircon U-Pb ages and whole-rock Sm-Nd ages for the Foping metamorphic crystalline complex in the central part of the orogenic belt. The SHRIMP zircon U-Pb ages are very complex； except for small amount of Archean zircon， there are also significant amounts of Proterozoic to Phanerozoic zircon.The metamorphic peaks occurred at -1 200， 800， 400 and 200 Ma. Gneiss has a Nd model age tDM of 1 372-208 Ma. The main part of the Foping metamorphic crystalline rock series possibly formed in the Paleoproterozoic， with an age of -2 000 Ma. In the subsequent strong geological processes， a small amount of mantle material was introduced. The view of the formation of the rock series in the Neo-archean has not been verified by the authors. Archean crystalline basement rocks may occur or may have occurred in the central part of the Qinling orogenic belt.

Abstract:Abstract：High-precision SHRIMP U-Pb dating was performed on zircon from quartz diorite and diabase in the Xinqiao Cu-S-Fe-Au deposit， Tongling ore district， Anhui. Zircon from quartz diorite yielded a 206Pb/238U age of (140.4±2.2) Ma， while the zircon age of diabase is relatively complex. Several Proterozoic zircon grains were found in diabase， which yielded 207Pb/206Pb ages of (2 261±14) Ma， (1 612±8) Ma， (919±12) Ma and (831±17) Ma. In addition， there is also a group of Early Paleozoic zircon grains， whose 206Pb/238U age is (443±13) Ma. The above new data give the information of the possible existence of Proterozoic basement in this district， and Yanshanian magmatism is of great significance for mineralization in the district.

Abstract:Abstract： Sr and Nd isotope analysis and zircon U-Pb dating were performed for Late Triassic volcanic rocks in the Gêladaindong area in the source region of the Yangtze River. The zircon U-Pb age is 212±1.7 Ma. The initial Sr isotope ratios of basalt and andesite range from 0.703 25 to 0.709 17 and from 0.70545 to 0.708 44 respectively， the εNd(t) values are negative， ranging from -0.8 to -4.6， and tDM ranges from 1064 to 1 379 Ma， which indicates that the primary magma of the Late Triassic volcanic rocks might be of crust-mantle mixing type. These ages， combined with the related major element， rare earth element and trace element geochemistry， suggest that the formation of this suite of volcanic rocks was related to the island arc-active continental-margin environment.

Abstract:Abstract：Since the 1970s， the stratigraphic sequence and age of the Neogene in the Nanjing-Yizheng area have long been controversial because the contact relationships between the Yuhuatai Formation and other sand-gravel beds have not been found. After restudy and division of the Xinyi No.1 hole section at Dayiji， Yizheng Town， the authors find that the superimposition relation of various strata of the Neogene is distinct. Based on this relation and previous work， combined with an analysis of other sections and lithofacies and paleogeography， the authors discuss the stratigraphic sequence and age of the Neogene. The stratigraphic sequence of the Neogene in the area includes the middle Miocene Dongxuanguan Formation (N1d)， late Miocene Liuhe Formation (N1l) and Huanggang Formation (N1h) and Pliocene Yuhuatai Formation (N2y)， as well as an informal lithostratigraphic unit-the Fangshan basalt (fb). The Yuhuatai Formation is another sand-gravel sequence overlying the Liuhe Formation and its age is late Pliocene.

Abstract:Abstract：74 species of spores and pollen of 53 genera are found in the Lower Jurassic deposits in the Toksun subbasin of the Turpan-Hami basin， northwestern China. Through an analysis of the changes in contents of typical general and species and dominant components， two sporopollen assemblages may be distinguished in ascending order as follows： the Osmundacidites - Protopinus - Cycadopites assemblage and the Cyathidites - Piceaepollenites - Cycadopites assemblage. According to the features of the sporopollen assemblages and comparison of related fossil assemblages in China and abroad， the age of the Badaowan Formation should be early Early Jurassic， and the age of the Sangonghe Formation should be late Early Jurassic. At that time the vegetation of the Toksun area consisted of such arbores as Ginkgo， Cycadopites and Coniferales， associated with herbs such as Filices. The paleoclimate should belong to the subtropical one.

Abstract:Abstract： Take for example the Baguamiao gold deposit and Bafangshan-Erlihe lead-zinc deposit, a comparative study has been conducted of the characteristics of ore-forming fluids of gold and lead-zinc deposits in the Fentai ore district, Qinling Mountains. Study indicates the following： the gas phase composition in fluid inclusions of all deposits in the district is of CO2-N2-CO-CH4-H2 type, but in comparison with lead-zinc deposits the CH4 value in different mineralization stages of the Baguamiao gold deposit is notably high, while its f o2 and f s2 values are low； for the liquid phase composition, except the values of Ca2+/Mg2+ and Eh which are lower than those in lead-zinc deposits, the values of Na+/K+, Cl-, F- and pH in the main metallogenic epoch of the Baguamiao gold deposit are all higher than those in lead-zinc deposits, and the ore-forming fluids in the main metallogenic epochs of both types of deposit are mesosaline but the salinity of the gold deposit is markedly higher than that of the lead-zinc deposits；δD and δ18O in fluids indicate that the water in ore-forming fluids of the lead-zinc deposits is mainly connate water, while most of the water in ore-forming fluids of the Baguamiao gold deposit is magmatic water or connate water heated by magma, whose metallogenic relation is closely related to magmatic hydrothermal fluids.

Abstract:Abstract：The Weiluo ball clay deposit occurs in the Pleistocene in the Nanning area, Guangxi. It has been proven a large clay deposit with reserves of more than two million tons by Guangxi No. 4 Geological Party. The ball clay consists of disordered kaolinite, mostly occurring as pseudo-hexagonal flaky kaolinite deposited as colloidal sediments in lake and bog basins. It is unconsolidated or not recrystallized, showing a high degree of ordering and high cohesiveness. The ball clay is very fine in grain size, being 0.94 μm on the average. The index of plasticity is up to 47-53 and the refractoriness is up to 1 750-1 790 ℃. The average content of kaolinite in the clay layers is 89%-94%, higher than that in ball clay deposits in Britain and the United States. The ball clay has large reserves and easily open-mined； so it is the best of this kind in China and comparable to the high-quality ball clay mined in Britain and the United States. However, it is being mined by the local people using the indigenous method for refractory material uses. It should be mined on a large scale with the modern techniques and sold as high-tech fillers and coating materials to supply domestic and international markets.

Abstract:Abstract： The Chenjiazhangzhi gold deposit is an epithermal cryptoexplosive breccia-type gold deposit discovered newly at the north margin of the Northern China plate and in the eastern segment of the Inner Mongolia axis. The deposit is hosted in a near-surface intruded into Archean metamorphic series of the Jianping Group and early Yanshanian granite. From the center outward the cryptoexplosive breccia pipe shows apparent zoning of rock types： the central part is cryptoexplosive clast-bearing crystal and lithic tuff, and outward clasts increase in size and the rock gradually grades into shatter breccia. The breccia has been intensely altered and shows pronounced alteration zoning. The alteration includes mainly sericite-quartz alteration and carbonation and subordinately silicification, adularization, argillization and propylitization. The gold bodies occur as veins in the west-central part of the breccia pipe. gold minerals are mainly present in fissure gold and intercrystalline gold. Yanshanian acid cryptoexplosive breccia pipe, silicification, adularization and sericitization, and Au, Ag, Cu, Pb, Zn, Bi and As anomalies are main indicators of gold prospecting.

Abstract:Abstract：Coal beds in the Qinshui coal methane field vary in thickness between 1 and 2 m, being generally 6 m thick. The degree of thermal maturity Ro ranges from 2.6% to 3.7% and the coal methane resources are abundant with a gas content of > 14 m3/t. The components and carbon isotopic composition of coal methane suggest that the coal methane of thermal origin in the Qinshui coal methane underwent deadsorption, diffusion and migration, it was concentrated and accumulated in the structural high, and the coal methane accumulation has been well preserved after its formation. Owing to the above-mentioned three factors, coal methane in the Qinshui coal methane field has good conditions of accumulation formation.

Abstract:Abstract：By using the existing data of landslides obtained in the survey, combined with the field observations, this paper presents the results of statistical analysis of such parameters as elevations, slopes and heights of the landslides documented along the upper reaches of the Minjiang, Dadu and Anning rivers on the western Sichuan Plateau and makes a comparative study of these statistical results and the geomorphological features of deep-cutting river valleys. Study shows that the majority of the landslides occurred at elevations of 1 500-2 000 m above sea level along the upper Minjiang River valley and the Anning River valley, while the landslides in the Dadu River valley mainly occurred at elevations of 1 000-1 500 m and 1 500-2 000 m. The slopes of the landslides in these areas range between 15°and 35° but 45.21% of the landslides in the Minjiang River valley took place on slopes of 35°- 55°. The landslides of the Dadu and Anning river valleys mainly occurred on slopes of 15°and 45°. It is pointed out that the great majority of the landslides on the western Sichuan Plateau occur in deep-incised “V”-shaped valleys and are mainly controlled by the morphological features of the river valleys. The Late Quaternary rapid uplift and deep incision of valleys are two main internal dynamic factors for controlling the occurrence and distribution of geohazards on the eastern margin of the eastern Qinghai-Tibet Plateau.