Abstract:Abstract：Recent advances of exploration geochemistry in China are reviewed including (1) In-depth study of the tremendous amount of data obtained in past geochemical mapping projects for: (a) better planning of future exploration in China. (b) pediction of ore reserves potential by using the idea of minerelization coefficient, general, regional, and spcified (MCG, MCR & MCS). (c) new idea and methodology for searching economic & independent Se, Te, Ga, Ge, In, Tl deposits. (d) understandings of the evolution of S. China tin and tungsten granites from Archaean to Yanshan period. (e) calculation of the fractionation coefficients to describe the behavier of Pt, Pd, Os, Ru, Ir, Rh during and after the formation of SW China mantle plume, (2) advancement of 76 element analytical scheme and new data quality monitoring procedure using the idea of virtualized standard maps. (3) New idea and methodology in deep penetrating Geochemistry including micro-sieving method and micro-phase analysis. (4) new program of regional geochemistry with overburden drilling. (5) Eco-agro-evironmental mapping program to cover whole China. (6) New idea and methodology for geochemical mapping in global scale based on the fractal self-similiarity principle controlling the distribition of elements in diff kinds of sediments. In order to widen the scope of exploration geochemistry in 21st century 12 big geochemical programs are suggested, all based on the ideas that maping in diff scales and of nearly all elements in the periodic table provides the foothold for the advancement of exploration geochemistry in the 21st century, that close integretion of mapping, research, exploration and engeieering (drilling, trenching, etc) are necessery, for increarsing the success of discoveries, that establishment of a global geochemical mapping research center in IGGE, China with our new mapping cocept will promote to get a global picture of elements distribution in earlier days.

Abstract:Abstract：In the study of the 3-D velocity structure in the mantle of East Asia, West Pacific Ocean and the globe using the high-resolution tomographical techniques of both natural seismic surface and body wave, the authors discovered a giant composite mushroom-shaped low-velocity mantle plume with the depth of over 2000 km, which, combined with the indicators of geology, geochemistry, and geophysics, is named the South China Sea composite mushroom-shaped mantle plume. This paper describes geological, geochemical, and geophysical features of the plume, divides it into such parts as the tail, the main body, the head, the mantle apophysis, and the basalt hot spot, develops a tentative 3-D geometric structural style for the plume, and discusses the dominant role that the plume and its derived mantle dynamics have played in the basin spreading of the South China Sea and the impact of the interaction among the Eurasian, the Philippine, and the Indian-Australian plates on the basin evolution.

Abstract:Abstract：The 1∶250000 Changde Sheet strides across Wuling uplift and Jianghan-Dongting basin from west to east, characterized by complicated Quaternary uplift-depression tectonic framework. Based on detailed geological mapping and lots of borehole data, the authors conducted tectonic-sedimentary landform classification and mapping of this sheet according to Quaternary tectonic activity, sedimentation and present elevation and topographic characteristics. Types of tectonic-sedimentary landforms were derived from decomposition of traditional landform types based on Quaternary geological process. Ten types of tectonic-sedimentary landforms were defined, namely, rising-denudation middle-low mountain (Ⅰ), uplift-denudation hilly area (Ⅱ), sedimentary and later uplift-denudation hilly area (Ⅲ), sedimentary and later uplift-denudation hilly plateau (Ⅳ), eluvial-slope wash hilly plateau (Ⅴ), isolated hill (Ⅵ), subsiding-sedimentary and later uplift-denudation hilly plateau (Ⅶ), subsiding-sedimentary and later uplift wave plateau (Ⅷ), stable sedimentary low plateau (Ⅸ) and subsiding-sedimentary low plateau (Ⅹ). A detailed analysis shows that every type of tectonic-sedimentary landform possesses its unique characteristics of elevation, Quaternary uplifting-falling activity, weathering-erosion and sedimentation. Tectonic-sedimentary landform classification and geomorphologic map not only show geographic environments but also provide effective means for direct and visual expression of Quaternary strata, tectonic features and geological-environmental evolution. In addition, these means will promote and deepen researches on Quaternary geology and environment of the Jianghan-Dongting basin.

Abstract:Abstract：Syndepositional rift obviously controls the deposition-filling process of the steep slope rift belt in the terrestrial fault basin. Two key rifts, i.e., Chenlan and Shengbei, are developed along the steep slope rift belt in Dongying terrestrial fault basin. The Chenlan rift controls the basin evolution, whereas the Shengbei rift controls the deposition. Clastic components in the steep slope rift belt chiefly came from Chenjiazhuang bulge, Binxian bulge and Qingtuozi bulge. Controlled by the tectonic setting and provenance, alluvial fan, fan-delta, nearshore subaqueous fan, delta and fluxoturbidite-fan were filled in the steep slope rift belt. There exists a typical temporal and spatial evolution in order of alluvial fan→nearshore subaqueous fan→fan-delta→fluxoturbidite-fan→lake. Having good physical properties and strong tectonic activities and being close to oil sources, the steep slope rift belt constitutes a favorable oil and gas accumulation place.

Abstract:Abstract：The Fenghuangshan copper deposit is the largest skarn type Cu deposit in the Tongling polymetallic (Cu, Fe, Au) ore cluster area. The Xinwuli pluton in the ore district is a Late Yanshanian high-K calc-alkaline intrusion (with U-Pb zircon age of 144 Ma), which is composed of quartz monzodiorite envelope and granodiorite interior part. Geochemical characteristics of the Xinwuli quartz monzodiorite indicate that the original magma was upper mantle alkli basalt, which was contaminated by crust materials during the intrusion. Curst material contamination might have happened during partial melting or upward migration of the magma. Cu mineralization has close spatial, temporal and genetic relationship with the Xinwuli pluton. Ore bodies are hosted by both quartz monzodiorite and marble along the contact zone, with endoskarn ore bodies being dominant. Similar trace element features of ore samples and quartz monzodiotite indicate that copper might have been derived from the monzodiorite intrusion. Fluid bimetasomatism between quartz monzodiorite and carbonate rocks caused Cu precipitation. Ore bodies are jointly controlled by bimetasomatism and structural deformation in three-dimensional distribution, resulting in the distribution of breccia ores along the contact zones. The whole mineralization history can be classified into the high temperature skarn stage and the middle-low temperature hydrothermal stage.

Abstract:Abstract：Iron resources in the second ore district of Gongchangling is not only a large-sized banded low grade iron ore deposit but also a large-sized high grade iron ore deposit. Since 1949, it has become the main mine providing high grade iron for the Anshan Steel Iron Group Cooperation. The authors studied the second ore district of Gongchangling, and analyzed major elements, trace elements, rare earth elements of the amphibolites. Some conclusions have been reached: ① the average compositions of major elements are SiO2 49.89%, TiO2 0.86%，Al2O3 14.85%, Fe2O3 3.47%, FeO 7.88%,MnO 0.24%, MgO 7.94%, CaO 8.65%, Na2O 2.79%, K2O 1.17%，and P2O5 0.07%, similar to things of basalt: MgO and CaO are high, Na2O＞K2O;②as for trace elements, the content of compatible elements (Sc, V, Cr, Co, Ni, Cu) is high, (Rb/Yb）N=5.95～132.93, with an average of 49.34; Rb, Ba, K, Sr, Zr, Hf are enriched, whereas Th, U, P, Nb, Ti are depleted, similar to things of deficiency type mid-ocean ridge tholeiite;③REE:∑REE ratios are relatively low (21.09×10-6～69.13×10-6, averagely 40.44×10-6), LREE/HREE=1.70～2.58, (2.27 on average)；(La/Yb)N=0.93～4.27 (1.60 on average), and (La/Sm)N=0.87～3.28 (1.42 on average)；④the original rock of amphibolites is basalt and, according to the discrimination diagram of environment structure, the original rock of amphibolites should be mid-ocean ridge tholeiite.

Abstract:Abstract：Core observation shows that mafic volcanic and intermediate-acidic volcanic rocks were developed successively in Tahe area in Late Hercynian. These two types of volcanic rocks have different geochemical compositions. In mafic volcanic rock, K2O+Na2O=3.49%~4.25%，K2O/Na2O=0.18~0.38<1, large-ion lithophile elements (LILE) K, Rb, Ba, Th and high-field strength elements (HFSE) Nb, Ta, Ti, Zr, P are high, and δEu≈1, with no significant anomaly, suggesting that this type of volcanic rock belongs to the sodic series basalt. As for intermediate-acidic volcanic rock, K2O+Na2O= 6.86%~8.82%，K2O/Na2O=1.25~1.59>1, HFSE Nb, Ta, Sr, P, Ti are poor, LILE K, Rb, Ba, Th are high, and δEu=0.43~0.66<1, with negative anomaly, implying that this kind of volcanic rock is potash basaltic or high potassium-calcium alkaline-dacite. The HFSE ratios Th/Ta and Nb/U imply that basalt and dacite don’t have obvious affinity, the basalt originated from the mantle, whereas the dacite originated from the crust. A comparison with the igneous rocks of adjacent areas shows that the basalt and dacite are similar respectively to the basalt in Tazhong and the granite in South Tianshan in geochemical characteristics. An analysis of tectonic sub-diagram reveals that the basalt was formed in the intraplate rift, whereas the dacite and granite were formed on the edge of the island arc plate tectonic setting. As a special paleo-tectonic location, Tahe area has well-developed basalt and dacite, which are the coupling results of the intraplate main rift basin and the volcanic-arc edge.

Abstract:Abstract：Based on a mineralogical and petrological analysis of the Shiren Mountain block, the authors summed up the deformation-metamorphic characteristics of this block and the regularity of its changes under the influence of the Luonan-Luanchuan faulted belt. A migmatite zone is developed on the southern margin of the Shiren Mountain. In this zone, the rocks have been strongly folded and basite bands can be observed clearly. The metamorphic grade of rocks becomes weak from south to north. From the low amphibolite facies and amphibolite facies schist through gneiss to granite, dark minerals gradually decrease, showing a transitional relationship with granite. From south to north, with the increasing distance from the faulted belt, the rocks change from cataclastic to palimpsest in texture and from sheet to gneissic-palimpsest in structure. Generally, the changes assume a continuous and gradual process from strong to weak. The recrystallization type and boundary shape of quartz and the deformation of feldspar show that the deformation temperatures of the Luonan-Luanchuan faulted belt, the Shirengou Mountain block and the metamorphic rock block vary in the range of 300 ~550 ℃, belonging to the middle-high temperature condition. Under the influence of the late tectonic process, there appeared a phenomenon of non-coordination of the temperatures. The fractal dimensions of the dynamically recrystallized quartz grain boundary are in the range of 1.332~1.243 and tend to decrease with the increasing distance from the Luonan-Luanchuan faulted belt northward. Strain rates are in the range of 6.75577E-16 to 1.81072E-16, which belong to the middle strain rate condition. The strain rate and the distance from the fault belt are positively correlated with each other.

Abstract:Abstract：Abundant geological information can be obtained from trace elements and REE in sedimentary rocks, which may reveal the provenance attribute and tectonic setting and help to reconstruct the paleo-sedimentary environment. Geochemical characteristics of mudstones and rock salt from the 3rd Member of Paleogene Shahejie Formation in Dongpu depression of Bohai Basin were studied in detail in this paper. The results show that the samples have relatively high Sr and Ba and low Rb, V, Ni, Mn, Fe, Cr and Br. Concentrations of most of the trace elements are higher than their Clark values in the same sorts of rocks. The total content ranges from 47.1×10-6 to 268.02×10-6, and the average content is 181.55×10-6，which is similar to the average value of PAAS. The ratios of LREE/HREE range from 7.96 to 11.46, and the average content is 9.71. These data show that LREE are obviously richer than HREE, and the distribution patterns of the samples are characterized by “V”-shaped curve with obvious negative Eu (from 0.48 to 0.70) anomaly and indistinct negative Ce anomaly (from 0.89 to 0.97). In addition, the content of rock salts is much lower than their content in other samples. According to an analysis of the characteristic parameters (Sr/Cu, V/(V+Ni),（La/Yb）N, Sr/Ba,δCe and Ceanom), it is revealed that the study area belonged to continental sedimentation, and its paleo-environment was under the oxygen-free, anaerobic and saltwater condition. The characteristic parameters such as Eu, δEu, ωREE—ω(La)/ω(Yb), La/Th-Hf and Co/Th—La/Sc in the discrimination diagram can indicate that the source rocks were mainly intermediate-acidic felsic and mixed felsic/basic rocks as well as very insignificant sedimentary rocks, derived from detrital materials of Neihuang uplift and Luxi uplift.

Abstract:Abstract：In the central part of southern margin of Junggar Basin, the 3rd Member of Ziniquanzi Formation（E1-2z3）characterized by fine accumulation properties is an important oil and gas exploration horizon. There exists intimate relationship between the reservoir distribution and the material sources, and hence the material source system analysis is a key to hydrocarbon exploration. In this paper, an analysis of heavy minerals and a division of their assemblages were carried out for well data and field sections according to their type, quantity variation and distribution in the study area. In addition, statistics of sand and conglomerate thicknesses as well as their spatial distribution characteristics were studied. It is found that there exist four material source systems in the 3rd Member of Ziniquanzi Formation in the central part of southern margin of Junggar Basin. The authors＇ study of the depositional systems and reservoir prediction in this area is of great significance for further researches.

Abstract:Abstract：The Kunlun orogenic belt was basically formed in Paleozoic, resulting from ocean-continent conversion and collision orogenic activity. In the early and middle Permian, the south Kunlun was a multi-island ocean basin, the north Kunlun was an active margin rift and contained mainly shallow sea sediments and partly volcanic basin sediments, the middle part was a seashore-shallow sea, and the Kangxiwa-Muztagh-Animaqing belt contained deep－semi-deep sediments and formed a multi-island ocean basin paleogeographic framework in this period. In the middle and late Permian, convergence took place, ocean basin and active margin rift were closed, uplifting began, and basin-mountain conversion was completed. In the late Permian, the Kunlun orogenic belt entered into another basin-mountain conversion period, sea water came from southeast in the east part and from northwest in the west part, with the deposition of seashore- shallow sea fragmental rocks and carbonate rocks in local areas. Based on field work, analytical tests and integrated studies in association with the 1：250 000 regional geological data and other data available, the authors chose the Permian strata of late Palaeozoic as the study object and discussed the Permian lithofacies characteristics and tectono-paleogeography with the purpose of improving the research level of the Kunlun orogenic belt.

Abstract:Abstract：Based on outcrop information, the authors made a detailed analysis of stratigraphic sedimentary facies of the Wumishan Formation in Lingyuan area of western Liaoning Province. Depositional environment of Wumishan Formation was divided into supratidal, intertidal and subtidal zones in accordance with the regularity of epicontinental sea tides, and the Wumishan deposition model was established. On the basis of sedimentary facies, combined with sequence characteristics of the interface, the Wumishan sequence was studied, four second-order sequences and twenty-two third-order sequences were recognized, and rock, structure and characteristics of systems tract of each sequence were described systematically. Sequence boundaries were mainly indicated by sediments and sedimentary structures, especially by exposed symptoms, of the shallow water environment. SQ1 is sequence type Ⅰ, Ⅱ-type sequence is more well developed, and SQ2-SQ22 is sequence type Ⅱ. Wumishan deposition in this area belongs to a shallow continental sea sedimentary environment, so that the depositional systems tracts belong mainly to transgressive systems tract and highstand systems tract, commonly with the lack of lowstand systems tract or shelf marginal sysrems tract. It does not have the environment for the formation of condense section either, which makes the maximum flooding surface and deep-sea condense section correspondingly.

Abstract:Abstract：Paleogene ore accumulations in eastern Chengdao Oilfield are controlled by lithology and concealed at depth, and hence sequence stratigraphy seems to be the best means in search for beneficial exploration areas of concealed oil accumulations. Therefore, it is crucial to carry out the research on sequence stratigraphy in this area. In view of the low exploration extent and unclear sedimentary facies belt and sandstone characteristics of this area and with the purpose of accelerating the exploration work in this area, the authors carried out a study of sequence stratigraphy and sedimentary characteristics on the basis of previous research work both at home and abroad. First, tectonic base-level cycles and long-term base-level cycles were identified according to grade division of base-level cycles based on high precision sequence stratigraphy. Then the Paleogene Dongying Formation was further divided into four mid-term base-level cycles. High resolution sequence stratigraphic framework of Dongying formation was established. It can be seen that different sequences or different parts of the same sequence of Dongying Formation have different distribution characteristics, with the general distribution pattern following the principle of volume distribution of sediments. The sedimentary system of the Dongying Formation circles had different characteristics in different periods: deep lakes and turbidite fans were mainly developed during the rising of the base level, the fan-delta system was developed at the early base level descending stage, the braided river delta system was mainly developed at the middle stage, and the low-tortuous river and alluvial plain system covered the whole area at the late stage. The results obtained by the authors are of active significance in analyzing the oil-gas distribution and controlling factors and guiding oil-gas exploration arrangement in this area.

Abstract:Abstract：The study of sediment source is significant in understanding and identifying favorable sedimentary facies belts and distribution of reservoir sands in the study area as well as in prospecting for favorable oil and gas reservoirs. The study area of this paper, Baiju depression, is at a low level of exploration. Research results concerning the sediment source of the 1st Member of Taizhou Formation are very insufficient. Based on an integrated study of dip logging data, heavy mineral data and core data, the authors probed into the orientation of the sediment source in this area. It is concluded that the sediment source of Yangxin secondary depression was derived from the Jianhu uplift in the northwest during the deposition of the 1st Member of Taizhou Formation.

Abstract:Abstract：Based on abundant well datas and core and outcrop observations, combined with geological setting as well as particle sizes and rock and mineral logging datas, the authors analyzed the sedimentary characteristics of widely distributed Late Carboniferous-Early Permian pebbly sandstones. It is suggested that they belong to the fan delta sedimentary system and were deposited in the epicontinental marine basin in the form of channel alluviation characterized by clear zonation in plane and obvious retrogradation structure in vertical section. The depositional structure was formed by the channel traction flow, with no obvious gravity flow deposition. The sandy conglomerate of high-energy braided channels and underwater distributary channels are their main skeletal bodies, whereas the river mouth bars are not well developed. Nevertheless, because of the effects of provenance, paleogeomorphic features and tide, the high-energy channel sand bodies of fan deltas with an important fluviation role have usually been reformed into barrier bars by tides, and hence they can also be regard as favorable reservoirs. Due to the difference in depositional characteristics, the reservoir space, reservoir property and oil-bearing properties of the fan delta are also evidently different. It is therefore concluded that the thick quartz sand belts formed by high energy channels seem to be the favorable facies belts.

Abstract:Abstract：Elements constitute the basic units of mineral rocks. They are sensitive to environmental changes. The characteristics of elements such as distribution，ratio and combination have recorded the information of environmental change during the evolution of sedimentary strata. These data are of important indicating significance in reconstructing sedimentary environment and studying the paleosalinity of marine carbonate rocks and the relative sea level change. The authors studied the sequence stratigraphic units of the Gaoyuzhuang Formation based on the element geochemical characteristics. The results show that, under the palaeoclimate influence， the paleosalinity， the relative sea level change and the element content in the carbonate as well as the related element ratios show obvious cyclic change characteristics. The methods of Sr/Ba and B have relatively high precision，which can serve as effective means for identifying and dividing the carbonate sequence boundary.

Abstract:Abstract：The gravel bed in Yichang is more than 100m thick and composed of 22 layers. It lies over Cretaceous red bed and covered with Middle Pleistocene plinthitic red earth. The authors analyzed the sedimentary facies of the gravel bed. The upper and middle fan subfacies of alluvial fan exist in Shanxiyao and Yunchi profiles from the bottom upward. There is a hiatus between Lijiayuan profile and the above two profiles. The middle and lower fan subfacies exist in Lijiayuan profile from the bottom upward. Grain size analysis also shows that the outcropped sand body has the characteristics of braided river and alluvial fan, which is consistent with the result of sedimentary facies analysis. It is thus concluded that the very thick gravel bed in Yichang is a typical alluvial fan and seems to be mainly the upper part of the fan. Such wide development of the alluvial fan can only occur under the condition of strong hydrodynamic action. Through a study of the geomorphology and environmental significance of the formation of the fan, the authors preliminarily consider that the outcropped gravel bed in Yichang was produced by the formation of the Three Gorges. Data available also show that the gravel bed was formed in 1.08～0.73 Ma B.P., whereas the Three Gorges were formed before 1.0Ma B.P.

Abstract:Abstract：The northern part of the Pre-Caspian Basin of Kazakhstan is rich in oil and gas, in which 39 oil and gas fields have been found. Lower Carboniferous and lower Permian strata constitute important oil and gas producing horizons. Recent exploration indicates that there exist lots of beach facies limestones of Middle Carboniferous Bashkirian stage, suggesting that the Middle Carboniferous strata may become a new exploration target. Based on the exploration data, this paper has made a detailed description of macroscopic and microscopic features of Bashkirian beach facies limestones, which will provide an important clue to future oil and gas exploration.

Abstract:Abstract：Located in the western part of the Minxian County-Lixian County metallogenic belt, West Qinling Mountains, the Zhaishang gold deposit is a recently discovered large-sized Carlin-type disseminated gold deposit. Examination of ores by optical microscope, electron microprobe and X-ray surface scanning has revealed that the ore deposit is quite complex in mineralogy. Up to now more than 40 minerals have been identified. These minerals include not only sulfides and sulfosalt of Cu, Pb, Zn, As, Mo, Ni and Sb -bearing minerals, a variety of oxides, sulfate, carbonate, and tungstate minerals but also visible gold grains, tellurides, native metals, and polymetallic intermetallic compounds. Among the most common minerals there are native gold, pyrite, chalcopyrite, tetrahedrite, galena, sphalerite, stibnite, quartz, calcite, ankerite, siderite, and barite. The identification of some rare minerals in the Carlin-type gold deposits such as chalcostibnite, bournonite, zinkenite, molybdenite, coloradoite, melonite, native metals, Cu-Zn-Ni-Sn-Fe intermetallic compounds and scheelite is of great significance. The diversity of mineral species in the ores and the occurrence of visible native gold minerals constitute outstanding features of the gold deposit. Dissolution of ferruginous limestone in the host rocks and sulfidation of the dissolved iron by H2S introduced by ore fluids were not only the most important depositional mechanism for visible gold grains but also the advantageous conditions for gold enrichment in the Zhaishang gold deposit.

Abstract:Abstract：The Lala copper deposit is located in the southwest margin of the Kangdian Axis in Sichuan Province, with the Paleoproterozoic metamorphic volcanic rocks as its ore-bearing country rocks. The ore deposit is a sedimentary-metamorphic copper deposit of volcanic eruptions. Through geological investigation, microscope identification, electron microprobe analysis and other means, the authors studied the modes of occurrence of ore fabric, the main useful components and associated elements of molybdenum, cobalt, gold, rare earth elements and platinum group elements. The useful associated elements occur mainly as independent minerals and subordinately as isomorphism. Minerals of platinum-group minerals, such as ore of bismuth-telluride-nickel-palladium and ore of telluride-palladium-nickel, were found, which shows the great comprehensive utilization value of this ore deposit. Suggestions for further utilization are also put forward in this paper. According to field characteristics of the ore deposit and fabric characteristics of the ore, the ore-forming process can be divided into sedimentary ore-forming stage of volcanic eruptions, hydrothermal metamorphism stage and supergene stage.

Abstract:Abstract：Located in the Zhaxue-Yaguila metallogenic belt of the Nyainqentanglha Range, Tibet, the Dongzhongla ore deposit is a newly-discovered lead-zinc polymetallic deposit. The exposed porphyry granite has an intimate relationship with the Dongzhongla ore deposit. In order to determine the accurate age of the porphyry granite in Dongzhongla, the authors employed the zircon SHRIMP U-Pb isotope dating technology and obtained the age of 124.4±1.9 Ma（MSWD=5.09）, indicating Cretaceous. This age is essentially in agreement with the event of magmatism in the east of the Gangdise-Nyainqentanglha volcanic-magmatic belt (from 109 Ma to 130 Ma) and the age of granites in the Zhaxue-Jinda lead-zinc polymetallic metallogenic belt. Combined with regional data, it is suggested that the Dongzhongla early Cretaceous porphyry granites resulted from the crustal thickening melting of the intra-arc rift tensional system. This age provides the important evidence for Cretaceous magmatism and helps to direct studies related to lead-zinc molybdenum-copper polymetallic ore exploration in the Nyainqentanglha Range.

Abstract:Abstract：The Pingshui copper deposit in Zhejiang Province is a typical volcanics-hosted massive sulfide deposit (VHMSD) in the northeast part of Qinzhou-Hangzhou collision belt between Yangtze and Cathaysia blocks. Its copper mineralization occurred mainly in the quartz-pyrite-chalcopyrite-sphalerite stage. This paper reports LA-ICP-MS U-Pb ages of zircon from sulfide-bearing quartz veins beneath the massive ore body. The results of dating are (981～988) Ma, (950±15) Ma, (926±13) Ma, (899±21) Ma and (93~120) Ma. CL images and Th/U ratios of the zircons show that both Neoproterozoic and Cretaceous zircons are almost of magmatic origin. Geological evidence and the findings indicate that the ore deposit was formed in the Neoproterozoic (~899 Ma) and the ores were affected by Cretaceous (93~120 Ma) thermal event. These results are of great significance for further researches on the genesis, formation and evolution of the Pingshui copper deposit and also provide chronological information in search for contemporaneous VHMSD along the Qinzhou-Hangzhou collision belt between Yangtze and Cathaysia blocks.

Abstract:Abstract：Located in Nanning County of Sichuan Province, the Paoma lead-zinc deposit is a stratabound deposit in a cataclastic zone of Lower Cambrian Maidiping dolomite. Being a reworked sedimentary stratoid (irregular) lead-zinc deposit, it includes two ore horizons. Pb and Zn in the ore deposit are economic elements possessing an average grade of 6%～9%, with the grade of rich ore in excess of 30%. The sphalerite Rb-Sr isochron age of 200±1Ma by TIMS method suggests an age of Late Indosinian-Early Yanshanian. This ore deposit has the same age as the Huize lead-zinc deposit in Yunnan Province, and therefore it is inferred that they had the same ore-forming setting.

Abstract:Abstract：The study of mantle-derived CO2 is one of the frontiers in Earth science and is hence of great significance. Mantle fluids in supercritical state possess high dissolving and diffusing capacity and serve as an important transporting carrier of energy in Earth’s interior, with their chemical composition being mainly H2O and CO2. Many scholars believe that mantle fluids play an important role in the ore-forming process, but research on their relation with the CO2 gas pool is very insufficient. Along with the magma rising, the relatively insoluble CO2 gas will be the first to release with the temperature and pressure reduction of the magma, and the favorable tectonic environment is likely to form the CO2 gas pool. Many of the world's regional magmatic activities and fractures have formed CO2 gas reservoirs. This paper analyzed properties and influencing factors of mantle fluids exemplified by the study of magma and fault characteristics of Bohai Bay basin in eastern China, and discussed the ascent and evolution process of mantle fluids. The authors believe that mantle degassing may be the main material source of CO2, and that fault activities provide passageways and space for magma uprising and gas migration and accumulation. The favorable sites in search for potential CO2 gas pools lie in magmatic activities on basin margin and intersections of faults of different directions.

Abstract:Abstract：Based on statistics and analysis of morphological content of eight heavy metal elements, the authors tentatively summed up the composition of their morphological characteristics and analyzed geochemical behaviors of these heavy metal elements in soil. The correlation between the effective content and the total content of heavy metal elements and pH, TOC of the soil are conducted by using the method of correlation analysis. It is concluded that the effective content of heavy metals is controlled not only by the level of the total content but also by pH, TOC of the soil. The results obtained provide a theoretical basis for the scientific and rational assessment of the topsoil.

Abstract:Abstract：Plant fossils of 38 species in 22 genera in Middle Jurassic were collected from Lower Yaopo Formation, Upper Yaopo Formation and Longmen Formation on the southern slope of the Jiulong Hill in Mentougou district, Beijing. Statistical data show that the Middle Jurassic flora of the Western Hills in Beijing is dominated by Filicopsida（27.6%）, Cycadopsida（25%）and Ginkgopsida（25%）, among which Coniopteris with 5 species and Cladophlebis with 17 species were found. The Nearest Living Relatives Method and morphologic features analysis were used to analyze palaeoclimate. The result indicates that the nearest living relative plants of dominant fossils are Osmundaceae, Dicksoniaceae and Cycadopsida, which mainly live in a humid-warm tropical or subtropical climate, and warm-humid climate is also identified from the diversity of Cladophlebis, large feathery compound leaves of Cycadopsida and coarse stems of Equisetales, etc. Consequently, the Middle Jurassic flora in the Western Hills of Beijing reflects a humid-warm subtropical climate. In addition, the climate had changed into drier and warmer according to the species and the quantity reduction of plant fossils from the Lower Yaopo Formation through Upper Yaopo Formation to Longmen Formation.

Abstract:Abstract：At present, the estimation of soil carbon reserves constitutes a basic problem in studying the global atmospheric carbon cycle. Based on soil carbon data obtained by multi-purpose geochemical survey in Hebei Province, the authors calculated the soil carbon reserves accurately according to soil types and land use classification so as to estimate soil carbon reserves in the southern plain of Hebei Province, with the adoption of the concept of unit carbon content in the GIS platform. The results show that the soil organic carbon reserves in the southern plain of Hebei Province come to 819402498 t, and their average soil organic carbon reserves are 13206.1 t/km2.

Abstract:Abstract：With the sandy aquifer lying in the seawater intrusion area of the Dagu River in Qingdao as the study object, the authors collected groundwater, seawater and the media to evaluate their composition and properties. Through seepage simulation of the process of seawater and fresh-water, the authors determined the regularity of the permeability and the main ions in the course of seawater and fresh-water displacement. Numerical simulation was also employed to study water sensitivity under the influence of ion exchange. The results indicate that, in the process of seawater displacing freshwater, ion exchanges of Na+-Ca2+, Na+-Mg2+ and Na+-K+ take place, with the ion exchange speed of Na+-Ca2+ and Na+-K+ fairly quick but that of Na+-Mg2+ relatively slow. During the course of freshwater displacing seawater, Ca2+ and Mg2+ in solution can replace Na+ and K+ in the media, with Ca2+- Na+ playing the dominant role. The kinetic parameters and the turning point of the breakthrough curve verify the water sensitivity phenomenon in the seawater and fresh-water transitional zone, Multi-component ion exchange leads to the phenomenon of water sensitivity.

Abstract:Abstract：Based on analyzing the test data of 1720 groups of water samples collected from the Dongting Lake area, the authors conducted a quality assessment of shallow groundwater in this area. On such a basis, this paper presents the secure water supply directions and puts forward suggestions and measures for secure water supply. The test data indicate that the shallow groundwater is mainly contaminated by the following eight indexes：Fe, Mn, pH, NH4-N, NO2-N，NO3-N, Be and COD. On the whole, the shallow groundwater in this area shows good quality, and hence it is mainly assigned to high quality water (39.37%), and subordinately to qualified water (26.04%) and unqualified water (34.59%).

Abstract:Abstract：GIS is used widely for its power in spatial data management and representation, but has been insufficiently employed in geological project management. With the construction of the projects management system in Strategic Mineral Prospect Survey as an example, the authors have analyzed the characteristics of the geological projects management, and proposed a technology which uses the ESRI Mapbjects 2.2 a geographic information system component to construct the system for managing the attribute and spatial data. In addition, a geological projects management system is developed and used in several projects management departments.