Abstract:Abstract：Gravity survey is a method commonly used in petroleum basin reconnaissance. Satellite gravity is favorable for studying lithospheric structure because from it we can not only get more deep information of inhomogeneity in the lithosphere but also resolve the gravity field into different layers to show the inhomogeneity at different depths. According to the satellite gravitational data, the lithosphere of the Xinjiang region may be divided into three megalayers. The top is a megalayer consisting of Meso-Cenozoic continental downfaulted basins, including the Yining basin, Junggar basin, Tarim basin, Tuha basin and Tarim basin, surrounded by the Altay, Tianshan and Altyn Tagh mountains. The middle megalayer consists of a series of Paleozoic marine parallel ranges and basins formed by strong compressional folding during the Indosinian-Yanshanian. The lowest megalayer is the low-density block basement. The sandwich lithospheric structure formed by reworking of the Xinjiang lithosphere beneath the continent assembled at the end of the Paleozoic due to Cenozoic northeastward subduction of the Indian plate. The Borohoro, Qapqal, Alagou, Erbeng and Horo mountains of the West Tianshan mountain system were uplifted transversely and they together with the South Tianshan mountain system divided the Xinjiang block into a series of new mountains and basins. This study leads to a conclusion that petroleum exploration in western China should not be restricted in Cenozoic basins but that we should consider the controls of deep structure on the basin-and-range structure exposed at the surface.

Abstract:Abstract：Plentiful Caledonian and Indosinian intrusive rocks outcrop in the Longshan complex in the eastern Qilian Mountains, but accurate chronological data are lacking. LA-ICP-MS zircon U-Pb dating of the Yanjiadian diorite in the Zhangjiachuan-Qingshui area of the eastern Qilian Mountains indicates that the isotopic age of the diorite is 440.2±0.92 Ma（MSWD=1.13），which suggests that the island-arc complex represented by the Yanjiadian diorite formed in the Late Ordovician. Studies of regional geology and tectonic evolution indicate that in this area there occurred northward subduction of oceanic crust represented by the Hongtubao ophiolite during the Middle-Late Ordovician and island-arc magmatic complex zones represented by island-arc type volcanic-sedimentary series of the Middle-Late Chenjiahe Group and the Late Ordovician Yanjiadian diorite body.

Abstract:Abstract：The Hudian deformed intrusion in the north of Baoji batholith consists of gneissic monzogranite. Zircons from the rock yielded a LA-ICPMS U-Pb age of 1770±13 Ma. Petrologic and geochemical study shows that the gneissic monzogranite formed in a subduction-collision environment on the plate margin and that the magma originated by partial melting of mid-upper crustal materials. The tectonic setting and age of this deformed intrusion are in the main consistent with those of the Gongjiangou deformed intrusion in the Taibai batholith, representing a strong tectono-magmatic event occurring in the western segment of the North Qinling orogenic belt in the terminal Paleoproterozoic and initial Mesoproterozoic. The event broadly corresponded to the Lüliang movement and might have certain genetic relation to the formation of the supercontinent Columbia. This new information has great significance for the study of the Proterozoic tectonic framework and tectonic evolution in the North Qinling orogenic belt and the dynamics of continental of China.

Abstract:Abstract：The SHRIMP dating technique was applied to determine the U-Pb ages of zircons from the Yiwulüshan granite, western Liaoning. The zircon samples were fresh and unweathered. The rock is coarse-grained biotite monzogranite. Through accurate measurements three ages were obtained; they are ~2500, 224 and 161 Ma. The upper intercept age of ~2500 Ma is the record of the evolution of the Archean old continental nucleus; the crystallization age of 224 Ma is the record of the Indosinian tectono-thermal event; and the magmatic emplacement age of 161 Ma is the record of orogeny of the main orogenic phase of the Meso-Cenozoic intracontinental orogenic belt in the Yanshan area and also an age when the regional structural regime started transition.

Abstract:Abstract：Study of the petrography and phase equilibria of typical metapelites from the low-pressure metamorphic sequence in the Altaides indicates that the P-T conditions are 445-550℃ and 0.2-0.6 GPa for the biotite zone, 480-566℃ and 0.54±0.22 GPa for the garnet zone, 601±20℃ and 0.8±0.25 GPa for the staurolite zone, 540±20℃ and 0.32±0.05 GPa for the staurolite-andalusite zone, 640℃ and 0.43 GPa for the sillimanite zone and 740-800℃ and 0.4-0.7 GPa for the cordierite-sillimanite zone. However, 632.4℃ and 0.785 GPa are not in the stable range of the andalusite but probably the medium-pressure metamorphic conditions of the orogenic belt in the early stage. For the 640℃ and 0.43 GPa of the sillimanite zone, as the garnet in the zone contains kyanite inclusions, it may also have undergone medium-pressure metamorphism. The low-pressure metamorphic sequence of the Altaides is not a normal metamorphic sequence and its field metamorphic gradient shows the “Z”-shaped character. The low-pressure metamorphism in the Altaides may have formed by compressional uplift of the medium-pressure metamorphic rocks at the early stage in a tectonic environment of extensive intrusion of collision-related granites.

Abstract:Abstract：The Middle Jurassic late Bajocian-early Bathonian Matuo Formation in Yanshiping, northern Tibet, is represented by mixed continental shelf deposits composed mainly of sandstone and mudstone with minor limestone. The condensed interval with shells, downlap and ravinement surface constitute the critical boundaries of the systems tracts of the Matuo Formation. The systems tracts are characterized by a binary structure, i.e. transgressive-highstand systems tracts, and the sedimentary thickness of TST is greater than that of HST. The parasequences are divided into three types, i.e. parasequences dominated by sandstones, parasequences dominated by mudstones, and upward-shallowing parasequences dominated by the tidal flat system. The prograding sequence and retrograding parasequence set is formed by parasequence stacking. A curve of relative sea-level change of the Matuo Formation has been established in the study area by using the depositional system method, and the constraints on the sea-level change in the late Bajocian-early Bathonian Matuo Formation in the study area have been studied based on a comparative study of the curve of sea-level changes in southern Tibet and the globe, combined with the data of oxygen and carbon isotopes and magnetic susceptibility. The eustatic sea-level changes control the early Late Bajocian sea-level change in the Yanshiping area, while the volume change of the regional oceanic basin caused by northward subduction of the Bangong Co-Nujiang suture is the primary factor responsible for the sea-level change during the latest Bajocian-early Bajthonian.

Abstract:Abstract：The sporopollen assemblages discovered in the Woma Formation in the Gyirong basin, Tibet, provide evidence for continuous and stable uplift of the Qinghai-Tibet Plateau during the Pliocene. Six assemblage zones may be distinguished in the Woma Formation in the Gyirong basin. The paleovegetation of the Woma Formation is characterized by subtropical, mountainous, needleleaf and broadleaf forest with Pinus and Abies as the constructive species, reflecting a warm-moist paleoclimatic environment. During the period, there occurred several pronounced climatic cold-warm fluctuations. Analysis of the lithofacies and paleogeography of the Woma Formation indicates that the depositional environment of the Woma Formation was mainly the fluvial and lacustrine one and locally the alluvial fan and swampy one. The evolution of the paleogeographic environment of the Woma Formation progressed through three stages, namely, the early formation stage, semi-open lake basin stage and enclosed lake basin stage.

Abstract:Abstract：The palynological records of the Pliocene Guge section in the Zanda basin, Tibet, show that the Guge section registers the process of vegetational and environmental variation in the study area from 4.40 to 2.74 Ma. During 4.40-3.75 Ma the climate was cool and dry and there appeared the landscape of needleleaf and broadleaf veld vegetation; during 3.75-3.47 Ma the vegetation belonged to mountainous, warm-temperate, mixed needleleaf and broadleaf forest and the climate changed from cool-dry to warm-moist; during 3.47-3.20 Ma the vegetation grew well, belonging to the mixed needleleaf and broadleaf forest, and the climate was mainly wet-warm; during 3.20-2.96 Ma the vegetation was characterized by alternation of mountainous, warm-temperate, mixed needleleaf and broadleaf forest and cool-temperate needleleaf forest and the climate began to become dry-cold; during 2.96-2.74 Ma the vegetation was characterized by mountainous, cool-temperate, dark needleleaf forest and the climate kept dry and cold.

Abstract:Abstract：Ichthyosaurs were one of highly successful groups adapted to the aquatic environment in the Mesozoic marine reptiles. However, only a few gut contents have been reported so far despite the fact that a number of articulated skeletons are known from this clade. Recently well-preserved ichthyosaur specimens have been found in the Guanling biota in the Lower Member of the Upper Triassic Xiaowa Formation in Guizhou, Southwest China. Among them, one specimen of Panjiangsaurus epicharis (YIGM V30016) with gut content is studied for exploiting the dietary habits of this taxon. The gut content is micrite with organic phosphatic biodetritus. The biodetritus is mainly composed of many small fish bone fragments with small quantity of bivalve shells. No gastroliths were found inside the gut contents. Panjiangsaurus, which had a long body and long tail and lacked blunt teeth, was probably an ambush predator, whereas post-Triassic ichthyosaurs were high-speed pursuit predators. It is indicated that Panjiangsaurus possibly fed on small fishes and bivalves, and that it did not need gastroliths for food trituration.

Abstract:Abstract：The geological section of the Lower Triassic Feixianguan Formation at Xiangshui Village, Guang'an City, Sichuan Province, is tectonically located in the western limb of the Huaying Mountain anticline and was paleogeographically located on the western side of the Early Triassic eastern Sichuan carbonate platform. Studying this section in detail is favorable to the reconstruction of the sedimentary history of the western side of the carbonate platform. The First Member of the Feixianguan Formation consists of semi-restricted neritic shelf facies and open platform facies deposits with marlstone. The lower part of the Second Member of the Feixianguan Formation is slope facies on the western margin of carbonate platform facies and open platform facies, while its upper part is relatively stable open platform deposits. The Third Member of the Feixianguan Formation consists of oolitic bank and open platform deposits, and the Fourth Member of the Feixianguan Formation belongs to diamictic tidal flat deposits. The Feixianguan Formation on the western side of the eastern Sichuan carbonate platform comprises two upward-shallowing depositional cycles. The second depositional cycle was the main period of westward accretion of the carbonate platform and development of oolitic banks.

Abstract:Abstract：Through a comprehensive analysis of the outcrops, rock cores, well logging and trace element data, five sequence boundaries of different origins are identified, and on that basis, the Upper Triassic Yanchang Formation in the Ordos basin is divided into four long-term base-level cycles (LSC1, LSC2, LSC3 and LSC4) that are persistent on a regional scale. Then the relationship between the source-reservoir-cap associations and the base-level cyclic sequences of the formation is discussed in detail and it is pointed out that the long-term base-level cycles bear close relation to the source-reservoir-cap rock association. The main reservoir sand bodies occur in the early and middle stages of the ascending half cycle and the middle and late stages of the descending half cycle of the long-term base-level cycle, and lacustrine mudstone and shale developed at positions of ascending and descending transition of the long-term base-level cycle are good hydrocarbon source rocks and cap rocks.

Abstract:Abstract：With the development of the petroleum industry, looking for high-quality reservoirs at depths becomes a problem that must be studied intensively. The Yongjin area is one of the three blocks in the interior of the Junggar basin explored by the Sinopec. The exploration target in the Yongjin block is deeper than 5000 m, in which most reservoirs have low and very low porosity and permeability. So looking for relatively high-porosity and -permeability reservoirs in the block is important. Regional unconformity between the Jurassic and Cretaceous is well developed. During the formation of the unconformity, meteoric water, which has a high flow rate and a relatively open fluid environment, dissolved minerals and carried the dissolution product out of the dissolution area; grain coats inhibited quartz enlargement and carbonate precipitation and conserved primary pores and secondary pores; in the Yongjin block hydrocarbon filled earlier and the earlier hydrocarbon filling improved the diagenetic environment of the fluids and restrained cementation; on the other hand, organic acid in the hydrocarbon dissolved more soluble minerals and generated secondary pores. All those together can preserve and improve the porosity of deeply buried reservoirs of sandstone in the Yongjin block, Junggar Basin.

Abstract:Abstract：Oil shale of the Luozigou basin is hosted in the 2nd Member of the Lower Cretaceous Dalazi Formation. It is buried at shallow depth with a gentle dip of strata and contains 3.51 to 14.37wt% of oil equivalent. Oil shale formed in a typical inland lake environments and contains many animal and plant fossils. Its genetic types are sapropel type(Ⅰmodel) and saprolite-sapropel type(Ⅱ1 model). The Dalazi Formation is a complete third-order sequence and the main oil shale beds, which have a high oil content and are persistent, formed in a transgressive systems tract (TST) and a highstand systems tract (HST). In a plan view, high-grade oil shale is located near the CK26, CK30, CK35 and CK40 holes and distributed in an E-W-trending strip. Vertically, a total of 29 oil shale beds are found, of which seven beds are extractable. Oil shale beds 2 and 3 occur as continuous and persistent beds with a high oil content. They have great economic value.

Abstract:Abstract：The regional distribution and occurrence and distribution of mineralization concentration areas, ore deposits and orebodies of orogenic gold deposits in the northern Qaidam margin-East Kunlun region were controlled by structures of different orders. In a second-order tectonic unit and/or metallogenic zone, orogenic deposits mostly occur near the tectonic boundary and/or a deep fault, i.e. the tectonic boundary of an orogen and/or a deep fault is the first-order ore-controlling structure of orogenic gold deposits in the northern Qaidam margin-East Kunlun region. Gold geochemical anomalies and orogenic gold deposits in a mineralization concentration area or an ore field are controlled by a large-scale shear zone developed at the side of a deep fault mentioned above, which is the second-order ore-controlling structure of orogenic gold deposits in the northern Qaidam margin-East Kunlun region. Folds and fault systems derived from the above-mentioned large-scale shear zone are the third-order ore-controlling structure of orogenic gold deposits in the region, which control the occurrence and distribution of orebodies in ore deposits. The Tanjianshan gold deposit and Dachang gold deposit are typical examples for fold controls on mineralization, while the Wulonggou gold deposit is a typical example of controls of mineralization by the fault-fissure system association with the shear zone. In contrast with those gold deposits under control of the fault system, the orebodies in gold deposits controlled by folds are larger in size and less variable in space. The tectonic boundaries of orogens and/or deep faults, large-scale shear zones and folds and fault systems derived from the above-mentioned large-scale shear zones mainly resulted form the regional Caledonian and late Variscan-Indosinian collisional orogeny, and they have about the same or interrelated geometry, kinematics and geochronology, of which the latter are commonly structures of lower order derived from the former. Therefore, the three structures of different orders form an ore-controlling structural system of orogenic gold deposits in the northern Qaidam margin-East Kunlun region.

Abstract:Abstract：Lead-zinc mineralization in the Mayuan area, Shaanxi Province, occurs on the southeastern margin of the Beiba uplift on the northern margin of the Yangtze platform. It, >60 km long and 10-200 m wide, may be divided into the north, east and south mineralization zones, in which over 40 lead-zinc orebodies have been delineated. The south mineralized zone is >20 km and 20-120 m. The east mineralized zone is >30 km long and 20-200 m wide, in which seven orebodies have been found at the surface. The north mineralized zone is >10 km long and 10- 100 m wide, and the orebodies are generally 100-2560 m long and 0.80-10.01 m thick with a zinc grade ranging between 1.5 and 10.82% and a lead grade of 0.55%-7.54%. The principal orebody has a length of 2560 m and ranges in thickness from 1.46 to 32.53 m, with a mean thickness of 7.60 m, and contains 1.45-11.42% zinc, averaging 4.47%. The mineralized zones are composed predominantly of dolostone of the Sinian Dengying Formation, occurring in doloruditic breccia of the Sinian Dengying Formation. The mineralization is mainly controlled by stratigraphy and structures. It is estimated that the Mayuan area has good ore prospects and potential for forming a superlarge lead-zinc deposit.

Abstract:Abstract：The paper discusses the geological settings, geological characteristics, metallogenic mechanism and ore prospects of the Leqingla iron deposit. The Leqingla iron deposit is located in the northern ore belt of the eastern segment of the Gangdise arc orogen and the orebodies mainly occur in the stratiform shape and are controlled by carbonate rock formations and interformational fracture zones. The host rocks are mainly skarn and skarnized limestone. The ore types are simple, dominated by magnetite ore. The enrichment of the mineralization is closely related to the early Himalayan Jubuzhari granodiorite, and the deposit is of skarn type. The potential resources of the Leqingla iron deposit is huge and there are ore prospects of the same type of iron deposit in the surrounding areas.

Abstract:Abstract：The content of platinum-group elements (PGE) in samples of sulfides and gold-bearing breccia from the Taibai gold deposit was determined by the nickel sulfide fire assay and inductively coupled plasma-mass spectrometry (ICP-MS). The results show that the PGE content in these samples is higher than that in the Baguamiao gold deposit, Qinling, but lower than that in the primitive mantle. Among the PGE, Pt, Pd and Ru are richer. According to the above-mentioned analysis, combined with the previous study of the sources and transport mechanism of the PGE, the authors think that the PGE may have been subjected to the deep sources, of which the IPGE (Ir, Os and Ru) might occur in the form of sulfides, while PPGE (Rh, Pt and Pd) might occur as simple substance.

Abstract:Abstract：The Garzê-Litang fault zone in Sichuan is one of the important metallogenic regions (zones) on the western Sichuan Plateau. The regional stream sediment survey and early-stage checks of anomalies have revealed rock gold occurrences with larger ore prospects at three gold anomaly sites with high gold concentrations, namely, Ajialongwa, Xionglongxi and Malong. In order to further find out ore information contained in the regional geochemical data, gold anomalies in the stream sediments were taken as the unit in the research work at the late stage and reevaluated in combination of new progress and knowledge in regional mineral prospecting; geochemical statistics and mineralization information prediction were made and target areas were screened with sampling grids as the unit; and a stream-soil-rock geochemical model for mineral prospecting was preliminarily constructed with the Ajialongwa gold deposit (including its surroundings) as the key target of research and ore deposit prediction was conducted. Through checks of the ore district by small amount of drilling, significant mineral prospecting results were obtained. Then after checking part of target areas in the surrounding areas, the Zhaiwulongwa and Adalong rock gold occurrences with larger ore prospects were found at places with weak dispersion flow anomalies. Thus the mineral spaces have been expanded.

Abstract:Abstract：The weights-of-evidence method is a discrete multivariate statistical method. It elucidates the concept of mineral resource potential areas and briefly describes the basic principle of the weights-of-evidence method. Take for example the southern segment in the "Sanjiang" metallogenic zone of southwestern China, the spatial relationship between various kinds of ore-forming information (ore-controlling factors) and mineral resource distribution is quantitatively analyzed by using the weights-of-evidence method on the basis of extraction of ore-forming information from geological, geophysical, geochemical and remote sensing geological data. Then the best ore-controlling factors are chosen as the variables for mineral resource assessments, which are used for calculating the posterior ore-forming probability of each unit. Eventually, ore-finding target areas are quantitatively delineated and evaluated according to their posterior ore-forming probabilities. This case study has illustrated that under the GIS environment the favorable mineralized areas can be effectively distinguished from the unfavorable ones through the combination of the "weights-of-evidence method" with ore-finding information so that the goal of fast quantitative delineation and assessments of the ore-finding target areas may achieved with the help of MORPAS3.0.

Abstract:Abstract：The basin-range junction zone has complex surface geological conditions and a rather undulate tomography, where deep seismic reflection data are characterized by a low S/N ratio, strong multifold noises and great lateral variation in velocity. According to the characteristics of these deep seismic reflection data, the authors used the ProMAX processing system to make refraction static correction, pre-stack noise attenuation, surface consistent processing, man-machine interactive velocity analysis, residual static correction circulating iterative processing, NMO based on surface and post-stack noise suppression on the 2-D deep seismic reflection data (or called the Spo4-2 profile) across the junction zone of the Zoigê basin and West Qinling orogen and found a set of processing method and flow process suited to the low S/N ratio deep reflection data of the basin-range junction zone. Finally they got the SP04-2 stacked section. The section for the first time reveals the lithospheric structure of the basin-range junction zone of the Zoigê basin and West Qinling orogen and offer a reliable seismologic basis for studying the contact relationships in the deep interior of the basin-range zone.

Abstract:Abstract：Studies of the origin and evolution mechanism of groundwater in a type area not only have great significance for guiding the rational utilization and development of geothermal water resources but also provide important information for future geothermal resource exploration and evaluation. The authors studied the formation and evolution of geothermal water in the Dezhou hollow based on an analysis of the chemical composition, isotopes and hydrogeological characteristics of geothermal water in the area. The study shows that: the formation of the geothermal water is controlled by deep faults and basement structure in the area; the geothermal water is recharged by meteoric water, belonging to penetrating metamorphic water; the hydrochemical components consist predominantly of more soluble salts; and gas components are mainly marked by a mixture of components originating from the atmosphere, crust and mantle ultimate source is meteoric water—all these reflect the various hydrochemical processes in long-term run-off and deep circulation of groundwater.

Abstract:Abstract：The study area belongs to an oilfield in Northeast China and the development of the oilfield has a history of nearly 50 years. With increasing demand for oil, vast amount of oil has been exploited. However, during exploitation, groundwater was polluted because of spilled oil and wastewater in this oilfield. Therefore, protecting groundwater from further pollution is essential to the health and safety of citizens in the oilfield. Based on an analysis of water samples, the authors have compiled a contour diagram of oil pollutant concentrations in groundwater in the study area and found that, except in a small scope where oil pollutants are distributed areally, most oil pollutants are distributed as patches in the study area. The contour diagram of oil pollutant concentrations, combined with substantial investigation and research on the geologic environment, structural setting, surface water flow and possible surface polluting source of the study, suggests that the oil pollutants mainly moved into groundwater by accidental pollution and ground cracks produced by over-development of groundwater and neotectonic fracturing. Due to long-continued over-pumping of groundwater near hole ZK6 in the study area, the direction of groundwater changed, and ground subsidence occurred and many ground cracks appeared at the surface; so groundwater pollution by oil is very serious. In addition, neotectonic faults inherited the NW, NNE and E-W sets of crustal faults, thus causing oil/gas in the underlying oil layers to move up along the fractures and pollute the overlying aquifers. Furthermore, large numbers of ground channels and ground cracks formed at the surface, and spilled oil and other pollutants polluted the aquifers through them.

Abstract:Abstract：Shijiazhuang is one of the cities suffering severe shortages of water resources in northern China, where a huge cone of depression has formed because of excessive exploitation of groundwater. Shijiazhuang is on the broad beach of the Hutuo River and its hydrogeological conditions allow surface water to directly penetrate into the cone of depression and recharge the groundwater. So, it is practically significant to recharge groundwater in Shijiazhuang the water diverted from the Yangtze River. According to different qualities of water from the Yangtze River, by using the existing appropriate groundwater recharging methods and related water purifying technologies and selecting the Hutuo River watercourse, sand pits on flood land and other favorable sites, the technologies of recharging Shijiazhuang groundwater with water from the Yangtze River are discussed and an appropriate engineering technology scheme is put forward, which is expected to serve the strategic control and management of water resources in Shijiazhuang.

Abstract:Abstract：The rapid scientific and technological and economic development makes higher demands on the environmental quality. The high level of environment quality requires that various kinds of environmental engineering can achieve the effect of protecting the environmental from pollution forever. The unique way to achieve this effect depends on geological barriers. Therefore, this paper makes a detailed argumentation of the basic function of geological barriers, safety assessments of geological barriers and how to use them to solve environmental problems by using a mass of experimental data and practical experience. The authors also propose that as China is provided with various advantageous geological conditions and many excellent useable geological barriers we should make full use of the basic theories of geosciences to deal with environmental problems and promote the environmental state and eco-environment to be better gradually.

Abstract:Abstract：Information services have become a strategic keystone of geological work in various countries in the 21st century. The geological information services based Internet and information technology can provide timely, effective, integrated and authoritative geoscience information and have been included in the strategic plan of national geological survey agencies of various countries. A consummate information service hierarchy is the prerequisite for the successful development of information services. Based on clarifying the related conceptions and definitions about geological information services, the authors analyze the features of modern information services, propose a relatively complete system framework of geological information services and elucidate the main content and relationships of various components in the system framework.