Abstract:Abstract：A crustal thickness and velocity structure model of continental China has been constructed based on a systematic structural analysis of the seismic sounding profile in continental China and its adjacent regions. According to this model, structural styles of crustal deformation, crustal geological structure and tectonic evolution and crustal kinematics and dynamics, the lithospheric crust beneath continental China is divided into six crust structure-dynamic types: (1) cratonic folded-thrust style structure-compressional dynamic type (Tarim type); (2) cratonic horst structure-extensional dynamic type (Ordos type); (3) thickened plateau fan structure-collisional wedging dynamic type (Tibetan Plateau type); (4) thickened orogenic wedge structure-subductional wedging dynamic type (Tianshan type); (5) thinned basin-range structure-block extensional dynamic type (North China type); and (6) thinned listric structure-wholesalely extensional dynamic type (South China type). This paper discusses the basic characteristics of cratonic crustal, thickened crust and thinned crust and their relations and geological significance.

Abstract:Abstract：Blueschists and eclogites are newly recognized in the Hongliuquan area, North Altyn Tagh. These blueschists and eclogites, together with metapelites, calcareous schists and quartz schists, form part of a coherent high-pressure (HP)/low-temperature (LT) metamorphic terrane, which occurs as a tectonic slab in faulted contact with ophiolitic mélanges. P-T estimates show that the peak pressure-temperature metamorphic conditions for the eclogites were 2.0-2.3 GPa and 430-540℃. Phengite from an eclogite sample and paragonite from a blueschist sample were selected for Ar-Ar dating. Phengite from eclogites yields an Ar-Ar plateau age of （512±3）Ma and an isochron age of （513±5）Ma, and paragonite from blueschists gives an Ar-Ar plateau age of （491±3）Ma and an isochron age of （497±10）Ma. These new age data suggest that the North Altyn Tagh HP/LT metamorphic belt probably formed earlier than the North Qilian HP/LT metamorphic belt and imply the existence of diachronism of subduction of the Early Paleozoic oceanic crust beneath the North Altyn Tagh-North Qilian.

Abstract:Abstract：Volcanic rocks of the Neoproterozoic Qingbaikouan Shangshu Formation in southern Hangzhou are composed of basic and acid rocks, while rocks of intermediate and intermediate-acid compositions with 57%-68% SiO2 are lacking. They form a bimodal volcanic rock association. There are evident differences in trace elements and rare earth elements (REE) between the basic and acid volcanic rocks, which indicates that the acid volcanic rocks were not produced by fractional crystallization of basic magma but formed by melting of different sources. The basic volcanic rocks originated from the less-depleted mantle or from magma of the depleted mantle contaminated with crustal material. The acid volcanic rocks mainly formed by different degrees of partial fusion of upper crust in an intracontinental to continental-margin extensional environment. The formation of the bimodal volcanic rocks in the Shangshu Formation is a petrological record of the breakup event of the supercontinent Rodinia in South China, which reveals that the breakup of the supercontinent Rodinia in South China started in the Qingbaikouan Period.

Abstract:Abstract：According to a rock geochemical study, basalt and andesite in the Neoproterozoic Wuyishan ophiolite mélange in the South China orogenic belt may be divided into two types: one is tholeiite, which is characterized by TiO2=2.26％-2.59％ (average 2.43), LREE being richer than HREE, (La)N/(Yb)N=6.4-9.4 (average 7.8), relative enrichment in Nb, Ta and Ti and the trace element characteristics being similar to those of OIB; and the other is of calc-alkaline type, which is characterized by TiO2=0.69％-0.93％ (average 0.83％), LREE enrichment, (La)N/(Yb)N=4.2-12.6 (average 8.4), weak negative Eu anomaly, lower Nb, Ta and Ti contents and enrichment in LILE such as Ba, Rb, Th and K, shows the characteristics of IAB and is the product of subduction. The two types of rock coexist in the ophiolite mélange and record the history of the subduction and closing of a paleo-ocean between the Yangtze block and Cathaysia block and arc-arc collision and amalgamation.

Abstract:Abstract：Abundant well-preserved radiolarians were discovered in cherts in the Artengkesi Formation south of Korgan, South Tianshan, Xinjiang. They comprise 21 genera and 46 species, of which eleven are indefinite species and one is indefinite genus. Study indicates that the radiolarian assemblages of two samples are Middle-Late Devonian and Early Carboniferous in age. The discovery of the Middle-Late Devonian radiolarian assemblage enriches the Devonian radiolarian fauna in the Kuqa area and provides fossil evidence for the determination of the age of the Artengkesi Formation. On that basis, combined with previous studies of fossils in this formation, the authors think that this formation is an age-straddling lithostratigraphic unit and should be disintegrated into the lower, Middle and Upper Devonian stratigraphic units. The abyssal sediments containing Early Devonian-Late Carboniferous radiolarian cherts provide stratigraphic evidence for the evolution of the South Tianshan paleo-ocean basin.

Abstract:Abstract：The Zhongjiannan basin, located in a continental shelf-slope area of the western South China Sea, inherits the geological characteristics of the tectonic domain of the northern continental slope and Nansha sea area of the South China Sea and its development was controlled by the western South China Sea marginal fault. So the Zhongjiannan basin has very complex structure. Study indicates that: various sedimentary systems such as continental facies, transition facies and marine facies are developed in the Zhongjiannan basin; in the basin there are swampy, lagoonal, shallow lake (sea)-semi-deep lake (sea) and semi-deep lake (sea)-deep lake (sea) environments, which are favorable for the growth of source rocks; intermediate to high geothermal gradients made kerogen mature easily; the main reservoirs are fluvial, fan, deltaic sandstone and weathered bedrocks and carbonate rocks. Controlled by the combined action of the global geodynamic systems produced by the interaction of the Pacific plate, Indian-Australian plate and Eurasian plate and affected by the regional stresses produced by sea-floor spreading of the South China Sea, the basin evolution has the features of polycyclic evolution, which resulted in the formation of several good source-reservoir-cap assemblages, fault systems and many types of trap. These geological elements provide excellent material conditions and storage spaces for the petroleum-bearing system of the Zhongjiannan basin. According to seismic exploration information of China and other countries, gas shows have been found in the uplift in the northwest of the basin and many places in the central and southern parts of the basin. In addition, Wu Bihao et al. of the Chinese Academy of Geological Sciences found bitumen fragments with fresh fractured surfaces in samples from the column of the surface of the sea floor of the Zhongjiannan basin. It was identified as stearine bitumen by the fluorescence microscope. All of these prove that the Zhongjiannan basin has the potential of hydrocarbon generation. In a word, the Zhongjiannan basin has good petroleum prospects and high value for petroleum exploration.

Abstract:Abstract：Located on the southern margin of the southern Qiangtang basin, the area is a "gap area" for hydrocarbon investigation. Detailed reconnaissance of 1:50,000 petroleum geological structure was carried out in the Zaring block of the Qiangtang basin, and according to the reconnaissance results the authors analyze two fossil oil accumulations in the Bi Qu Formation of the study area. Based on the types, textures, authigenic mineral assemblages and fossils of carbonate rocks in the sections as well as the characteristics of carbonate rock associations in the area, the Bi Qu Formation in the area is classified into four major sedimentary environments, namely, semi-restricted platform, restricted platform, open platform and shoal. Grain limestone showing the shoal environment is characterized by widespread occurrence, a great thickness, high porosity and high permeability, and its occurrence controls the size of reservoirs in the area. Dolostone showing the restricted platform environment forms another reservoir in the area. It is an effective reservoir, but its capability is related to the occurrence of the overlying strata. Micritic limestone with micritic calcarenite and calcirudite interbeds that formed in an open platform environment is a better source rock in the area, and its spatial distribution is strictly controlled by sedimentary facies. Micritic limestone with bioclastic limestone and micritic calcarenite interbeds formed in a semi-restricted platform environment is a favorable cover in the area, and the occurrence of the cover is also controlled by the nature of the semi-restricted platform environment.

Abstract:Abstract：In the Ordos basin, three depositional systems formed during the evolution of the lower Upper Paleozoic strata from marine to continental facies; they are in ascending order the barrier coast-tidal flat, delta and alluvial plain-braided river depositional systems, in which there occurs a terrigenous clastic coal-bearing sequence that has wide facies zones and a persistent lateral distribution. These depositional systems provided abundant source rocks and reservoir rocks and occur extensively in the same horizon or overlap each other over short distances; as a result, gas can be accumulated even though the conditions of large-scale migration passageways are lacking in the interior of the basin. The Daniudi gas field is located in the north of the Yishaan slope of the Ordos basin, and its basic framework is a large multi-layered lithologic trap developed in the Upper Carboniferous-Lower Permian. Sealed and covered by the argillite of the widespread Upper Permian Upper Shihezi Formation with unusually high pressures, this trap exhibits the features of near-source box-type accumulation. This is the main Upper Paleozoic accumulation-forming manner in the interior of the Ordos basin.

Abstract:Abstract：High-frequency sequence stratigraphic division of the Permian-Carboniferous in the Jiyang area has been made. Seven depositional sequences have been distinguished. Sequence I, II and III are of binary structure, that is, they are composed of transgressive systems tracts and highstand systems tracts. Sequences Ⅳ to Ⅶ are of tertiary structure, that is, they are composed of lowstand systems tracts, transgressive systems tracts and highstand systems tracts. The main coal gas reservoirs are developed in the lowstand systems tracts and highstand systems tracts in sequences IV to VII. The main frame sandstones are: the deltaic sand body of the deltaic plain dominated by distributary channel deposits; filling deposits of the river channel in the river system which are dominated by point-bar deposits; distributary channel deposits and sandy deposits of lakeshores and shallow lakes of the lake system dominated by lake delta and lakeshore sandy deposits; channel filling deposits and sandy deposits along the shore in the composite river-lake sedimentary system; and also flood fan deposits. The coal gas accumulations occurring in Permian sandstone (compact sandstone) are the most important natural gas accumulations. As the diagenesis of the Permian-Carboniferous sandstone was strong, scarce primary intragranular pores have been preserved and most intragranular pores formed by late-stage corrosion. Such secondary intragranular pores formed by late-stage corrosion of matrix or cement filling between the intragranular pores.

Abstract:Abstract：There are tectonic fractures, diagenetic fractures and fractures related to overpressures in the low-permeability sandstone reservoir in the Second Member of the Upper Permian Xujiahe Formation in the south of the western Sichuan depression. Among them, tectonic fractures are dominant. Under the stresses resulting from horizontal tectonic compressions in the Indosinian, Yanshanian and Himalayan periods, overpressures formed by deep burial in the Cretaceous and tectonic uplift and erosion since the Neogene, four sets of fractures formed in the study area. The development degree of these fractures was controlled by the lithology, layer thickness, structural locations, stresses and fluid pressures. The zones of fractures are mainly distributed along the N-S and NE-SW-trending structural belts. In the N-S-trending structural belt, nearly N-S and nearly E-W sets of fractures are better developed than the other two sets of fractures; whereas in the NE-SW-trending structural belt, the NE-SW and NW-SE sets of fractures are better developed than the other two sets. The fracture development zones control the concentration of natural gas in the study area.

Abstract:Abstract：Stratigraphic division and correlation are the basic and very important content of study during oilfield development. In various stages from oilfield development to adjustment, higher and higher requirements are set for the stratigraphic division and correlation. However, the underground information is limited in a real oil field. Firstly, when the well pattern density reaches a certain level, infill wells are not unrestricted. Secondly, the overwhelming majority of underground information is obtained by well logging, but the resolution of log data is limited. Therefore, during the wide application of high-resolution sequence stratigraphy, outcrop research is essential. Based on actual fan-delta outcrops, the authors have summarized the indicators of recognizing the high-frequency sequences, parasequences and parasequence sets in the fan delta of the outcrop area, quantitatively studied the distribution characteristics, geometry, internal structure and heterogeneity of sandbodies of different genetic types, transformed the outcrop indicators of the high-resolution sequence boundaries into underground core and log information and finally summed up general principles of sequence stratigraphic correlation on the basis of the outcrop research.

Abstract:Abstract：In the geological evolution of the Tarim basin, many transgressions and regressions happened, which brought plenty of salt-forming materials. Furthermore, because the climate was extremely arid, abundant halite was deposited. So it is possible to find potash in the Tarim basin. Through fieldwork, the authors have found that large amounts of halite and spring brine outcrop in the western Tarim basin. Based on a brief introduction of the geological characteristics and sedimentary facies and paleogeography of the area and chemical analysis of brine samples taken from the western Tarim basin, this paper discusses geochemical parameters and the possibility of potash formation. According to the results of brine analysis, the authors have come to the following conclusions: first, most brine has been leached from very thick halite; halite is mainly of chloride type and this type of halite has not reached the stage of potash deposition; second, the contents of Br and K show that Ohsalur (WKSL) is a place meriting attention because there have been some indications of potash deposits; finally, the Br content in the Tarim basin is generally low because of only primary deposition, which has been proved by the results of the experiment and collected data; so we cannot only depend on the Br index to judge the deposition stage of halite and it is necessary to find other potash-forming models in addition to marine potash formation.

Abstract:Abstract：Located in the Zhangtiantang area, southern Jiangxi, the recently discovered Yaolanzai deposit is a typical altered granite-type tungsten deposit. Through highly precise dating of the ages of petrogenesis and mineralization of the tungsten deposit, the authors obtained a SHRIMP U-Pb zircon age of 156.9±1.7 Ma (n=11, MSWD=3.3) for porphyritic fine-grained muscovite granite and Re-Os model ages of 155.2±2.3 to 156.5±2.1 Ma and an isochron age of 155.8±2.8 Ma (n=4, MSWD=0.49) for disseminated molybdenite in ores. According to the above-mentioned ages, combined with the highly precise age data obtained at a regional scale recently, the authors conclude that the tungsten deposits in this area formed in the Upper Jurassic, with their isotopic ages clustering at 150-160 Ma. There is no significant time gap(1-5 Ma) between tungsten mineralization and petrogenesis of its closely related granitoids. The W-Sn mineralization in the area corresponds to the regional-scale Mesozoic second large-scale mineralization in South China.

Abstract:Abstract：The Da'ao tungsten-tin deposit in the Jiuyi Mountains, southern Hunan, is closely related to the Jinjiling composite granite which has the characteristics of aluminous A-type granite. The deposit types include the greisen type, altered granite type, fractured zone alteration type and greisen-quartz vein type. Based on the precise Re-Os dating of molybdenite from the ore-bearing greisen-quartz vein, a mineralization age of 151.3±2.4 Ma was obtained, which is consistent with the formation age (151-156 Ma) of granite, suggesting that the mineralization occurred simultaneously with the rock formation. An integrated analysis and comparison of highly precise mineralization ages obtained on a regional scale shows that the period of 150-160 Ma was the peak stage of Mesozoic large-scale mineralization in the Nanling region and that the Da'ao tungsten-tin deposit in the Jiuyi Mountains is just the product of this peak stage. The new data provide important isotope chronological evidence for the further study of the regional metallogenic characteristics and guidance of regional mineral prospecting.

Abstract:Abstract：The Da'ao intrusion-type tungsten-tin deposit is hosted in the Jinjiling composite granite body. The paper discusses the genesis of the deposit and preliminarily summarizes the metallogenic model of the deposit according to the geological setting and characteristics of the deposit and results of Pb, S, C and O isotopic analyses of granite and ores. The deposit formed by the polyphase tectonic movements and magmatic pulsation and evolution. The metallogenic temperatures of the deposit range from 260 to 320℃, the salinities of ore-forming fluids range from 0.88% to 11.22%, the pressure is 862×105 Pa and the depth is 2-3 km. So the Da'ao tungsten-tin deposit is of intermediate- and high-temperature metasomatic origin.

Abstract:Abstract：The Yarlung Zangbo ophiolite belt is >1500 km long and may be divided into three segments: the east (Qüxü-Mêdog), central (Ngamring-Rinbung) and west (from west Saga to the Sino-India national border) segments. The west segment is further divided into the Dajiweng-Saga ophiolite zone in the north and Daba-Xiugugabu ophiolite zone in the south. The previous research focused on the east and central segments and very limited work has been done in the west segment. Ophiolite masses (blocks) in the Daba-Xiugugabu ophiolite zone are composed of mantle peridotite. The main rock types are harzburgite and dunite with rare lherzolite, while oceanic crust is lacking in the typical ophiolite section. The ophiolite masses are large and have pronounced facies zoning with extensive dunite facies. Many chromite mineralization occurrences have been found in the La'nga Co, Dongpo, Dangqiong and Xiugugabu masses. Orebodies occur in lenticular (podiform), short-vein and irregular shapes. Ore is mostly massive in structure and in a few cases disseminated, generally with a Cr2O3 content of over 40%. The chromite deposits are of podiform type. Comparative study indicates that the rock masses in this ophiolite belt are similar to the mineralized rock bodies hosting large podiform chromite deposits in the world in respect to the tectonic setting, ophiolite type, size of rock masses, rock composition, location of preservation, degree of partial fusion, geochemical characteristics of rocks and minerals and chromite mineralization characteristics. The Daba-Xiugugabu ophiolite zone has good metallogenic conditions and better ore prospects. The authors suggest that: dunite facies in the northwest part of La'nga Co mass is the target with the best ore prospects, and next are dunite facies and dunite-harzburgite facies of the Dongpo mass and dunite-harzburgite facies of the Dangqiong mass.

Abstract:Abstract：Migrating pingos are developed along active faults in the permafrost area on the northern Qinghai-Tibet Plateau. They may destruct oil pipelines, bridges and culverts in the area. 3D nonlinear finite-element numerical modeling is performed of the destruction of oil pipelines by using the ANSYS finite element general procedure. It reveals the stress field, displacement field and plastic deformation caused by freezing and expansion of the migrating pingo and presents the oil pipe bending deformation caused by the migrating pingo and stress distribution. Bending of pipes produces compressive stresses of -515 MPa and tensional stress of 520 MPa inside the pipes, which exceed the yield strength of 450 MPa for the pipes, thus leading to plastic deformation and destruction of the buried oil pipes. The modeling of oil pipeline bending caused by the migrating pingo may provide an important basis for pipeline engineering design and prevention and control of geohazards produced by the migrating pingos in the study area. Finally measures of prevention and control are proposed.

Abstract:Abstract：Through field observations and structural analysis and in light of the principle of classifying the joints according to their strikes and dips into conjugate joint sets and determining their phases, the joint structure developed in the Jinchuan dam area of the Dadu River was analyzed and studied. The authors classified the NE-, NW-, ENE- and ENE-striking and SW-, NE-, ESE- and WNW-dipping into four sets of conjugate joints, belonging to the regional NW- and N-S-trending structures respectively. According to this conclusion, the authors deduce that the formation and development of the joints in the area were affected and constrained by the regional Indosinian-Yanshanian NW-trending structural stress field and Himalayan N-S-trending structural stress field. The strata in the area dip SW, and the joints of the first phase dip in the opposite direction of the dip of the bedding of the strata, while the joints of the second phase dip in almost the same direction as the dip of the bedding. The joints of the second phase play the principal role in controlling the structural movement. In the civil engineering construction, joints of the two phases combine to cut the rock masses. The former is prone to crush rocks, while the latter is prone to form landslides. The study of the two phases of joints has great significance for the study of the engineering stability in the dam area of the Jinchuan hydropower station.

Abstract:Abstract：The data of sporopollen assemblages collected from Cenozoic strata in the Wenquan area in the interior of the Qinghai-Tibet Plateau indicate that: from the Paleocene to early Miocene, paleovegetation evolved from mixed needleleaf and broadleaf forests-forest grassland vegetation in the early stage to veld vegetation in the late stage and the paleoclimate also evolved from the warm-wet subtropical climate to warm-cool one; from Pliocene to early Pleistocene, broadleaf trees were obviously reduced, while herbaceous plants increased markedly, reflecting that the climate began to evolve towards the dry-cold climate; and since the late part of the middle Pleistocene, the evolution from veld vegetation to desert grassland vegetation appeared, which finally molded an environment of modern desert grassland vegetation represented mainly by Chenopodiaceae and Artemisia. The change of the ecological environment in the interior of the Qinghai-Tibet Plateau reveals that the Qinghai-Tibet Plateau has undergone at least three uplift events with ecological-environmental significance since the Paleocene. Fanglomerate sediments and sporopollen assemblages in the Paleocene-early Oligocene Tuotuo River Formation indicate that: the Qinghai-Tibet Plateau had been uplifted to the altitudes of 1000-1500 m above sea level by the terminal Cretaceous-early Paleocene and the plateau landform might have a framework of alternating high mountains and basins; the noticeable increase in subtropical components in the vegetation of the early Miocene Wudaoliang Formation might be related to the climatic wetness caused by plateau monsoons induced by the plateau surface uplift and it is inferred that the plateau had uplifted to 2000-2500 m above sea level. In the late part of the middle Pleistocene, herbaceous plants predominated, indicating that the type of plateau vegetation had changed and that the plateau has been uplifted to an altitude of more than 3000 m above sea level.

Abstract:Abstract：Trans boundary aquifers, as an important integral part of global groundwater resources, have great significance for managing the valuable water resources shared by adjacent countries and building a harmonious world. With the help of departments and organizations concerned and on the basis of the demarcaton of trans-boundary aquifers in Asia, the authors undertook research on trans boundary aquifers across the boundary of China and selected the Middle Heilongjiang-Amur River Basin shared by China and Russian to carry out a case study. This case study, as the first case study of the Internationally Shared Resource Aquifer Management (ISRAM)-Asia, will promote the implementation of the ISRAM-Asia program headed by China.

Abstract:Abstract：Karst recently discovered during relocation of migrants in the Three Gorges reservoir region is an important engineering geological problem. The Erlangmiao area in the new city of Wushan County is a geohazard monitoring and early-warning demonstration area. In the area, limestone of the Triassic Jialingjiang Formation underwent strong karstification due to the special climatic, hydrological and geological conditions, so the rock mass structure becomes very complex and massive limestone has been turned into layered, fractured rock masses, karst breccia, argillaceous bands and eluvial breccia layers. There are different features and intensities of karstification in different geomorphological zones. Generally, karstification increases from west to east and from the bottom of the section upward. Among other things, the zones of transition from the steep to gentle topography and the lower part of gullies are the strongest karstification zones. Karstification gave rise to an assemblage framework of various microlandforms and special rock masses. With karstification, the mechanical intensity and stability of rock masses decrease progressively, which, together with other natural processes and human activities, may cause geohazards such as uneven subsidence, ground cracks, landslides, avalanches, mudflows and ground collapses. Great attention must be paid to these problems in the process of migrants resettlement and future town construction.

Abstract:Abstract：Regional geochemical data contain abundant geological information and can be used in regional geological mapping in shallow overburden areas. The relationship between the chemical composition of stream sediments and bedrocks in shallow overburden areas is studied and the method of inferring the chemical composition of bedrocks is proposed by using the oxide composition of stream sediments and the chemical composition of regional rocks as the constraint. According to the mass balance between the chemical compositions of stream sediment and its minerals, the inference method of the mineral composition of bedrocks is presented. The compilation method of inferring geological maps according to the regional geochemical data is put forward and is tested in the typical forest-swamp overburden area and the validity of the method is verified by geological survey and drilling. Thus making full use of regional geochemical data to extract geological mapping information is a valid approach to improving the geological mapping quality in shallow overburden areas.

Abstract:Abstract：A comparative study was performed of the content of heavy metals in wheat and corn in an area of soil heavy metal pollution and a control area in a certain gold mining area in the Xiaoqingling Mountains. The study shows that: the cumulative contents of Hg, Pb and Cd in wheat seeds in the polluted area are obviously higher than those in the soil control area; there is almost no difference in contents of Cr, As, Cu and Zn between the polluted area and control area; and the above-standard rates of Hg, Pb, Cd, Zn and Cu in wheat are 86.67%, 60%, 33.33%, 6.67% and 20% respectively. In comparison with the control area, the Pb, Cd and Cr contents in corn in the polluted area are markedly high but do not exceed the set standards, only mercury being above the standard, with an above-standard rate of 15.15%. Wheat is easier to absorb heavy metals than corn at the same sampling site. There is a good correlation between the content of heavy metals in wheat and the degree of heavy metal pollution in soils. In contrast with 1990, the cumulative effects of Hg and Cd in wheat are very prominent. The heavy metal pollution of soils in gold mining area has caused serious pollution of wheat.

Abstract:Abstract：Natural placer mineral survey is one of the important methods of mineral investigation. It is a realistic problem how to fully extract mineralization information from placer mineral, give play to its role in mineral resources investigation. Denudation and re-deposition of heavy minerals is an important process in forming placer mineral. By giving adequate cansideration ot the natural precipitation catchment way, it is an objective explanation that the boundary of the catchment basin is the scope of the placer mineral anomalies. The research on the model of region mineralization, geochemistry and heavy mineral concentrate data are important supplements to the application of the placer mineral suruey data. This article analyses the placer muineral survey data of the Yuxian area (1:200,000) and makes some studies and attempts in respect to understanding and evaluating anomalies, using the investigation method, applying the software platform, looking for unknown mineral resources in areas where the level of mineral exploration and exploitation is relatively high.

Abstract:Abstract：The essential elements of the geoinformation service system include information service providers, objectives, contents and modes. According to the four elements, the authors intensively studied and analyzed the geoinformation service system in China and found the gap between China's system and the systems of developed countries. On that basis, the authors propose the key problems that should be solved and countermeasures for the improvement of China's geoinformation service system.