Abstract:Abstract:According to the information obtained by geological and geophysical work along INDEPTH- Ⅳ profile, the authors formulated a new model for the Kunlun Mountains orogeny based on detailed comprehensively studies. Some main viewpoints heldby the authors are as follows: (1)In the Early Permian, the subduction of Songpan - Ganzi Ocean toward the Kunlun- Qaidam block resulted in the formation of continental margin arc and extension area of arc. With the continuous collision and squeezing of Songpan - Ganzi and Kunlun-Qaidam blocks, there occurred different tectonic evolutions. (2)Old crystalline basement of Kunlun region was lifted up to form mountains and subjected to strong erosion during the face-to-face squeezing of the land masses, and hence the old crystalline basement and the plutonic rocks were exposed on the surface due to denudation. Kunlun terrane did not overthrust northward to the Qaidam. South Kunlun block thrust over the North Kunlun block, with the breaking depth reaching10 km. (3)The crustal thickening of Kunlun occurred mainly in the lower crust (6.2-6.7 km/s), mainly mafic lithosphere. (4)As the back- arc extension zone of the Kunlun Mountains, the Qaidam Basin was uplifted and experienced subsidence with the Kunlun orogenic uplift, and Cenozoic sedimentary thickness was 12- 14 km resulting from two sorts of actions (deposition and compression). Crystalline basement underwent rifting and formed a new rift, with the width of rift being about 12 km and the depthbeing about 4 km. The conductive zone implied that the rift was connected with the deep thermal fluids through the fracture. (5)The Moho depth of the Qaidam Basin is 52 km, that of the Kunlun Mountains is 65-70 km, and the Moho level lies near Golmud (with a distance of 185 km). (6)The flysch layer thickness of Songpan-Ganzi terrane is 10-14 km. Shallow layers were thickened by Tertiary Fenghuoshan thrusting. The underlying uniform velocity layer (with high conductivity display) is 6.2-6.3 km/s, which is a unique phenomenon of the terrane. The thickness of the accumulation of residual oceanic crust was 15 km, the shallow layer was thickened through Tertiary volcanic nappe system, and 15 km of thick rock bed squeezed into middle crust. (7)The model that Asian lithospheric mantle subducted into the Qaidam mantle lithosphere was denied. The authors hold that the Indian continental lithosphere mantle was separated into two layers, stretching northward along the bottom of the plateau and was subducted over the lithosphere mantle of Qaidam. That is a new way of length adjustment caused by the squeezing process of the north and south of the plateau.

Abstract:Abstract:In the Wilson cycle proposed in the 1960s, the collision of tectonic plates which leads to closure of oceanic basins on both sides of plates marks the end of the cycle. In interpreting continental tectonics in the past 20 years, it seems that the above conclusion is not comprehensive. Diffusive and widely distributed intracontinental deformation suggests that the action of platecollision has not ceased. After the formation of the Paleo- Asian continent, tectonic deformation, magmatism and cratonic basin formation widely developed during Mesozoic-Cenozoic period in eastern China were possibly related to the progressive opening of the Indian Ocean and the Arctic Ocean as well as the subduction of the Western Pacific and Philippine oceanic plates. This paper intends to discuss the major tectonic events, structural properties, the formation background and the temporal and spatial distribution of Mesozoic-Cenozoic tectonics in eastern China. From Late Hercynian to Indosinian period, the Paleo-Asian continent was formed due to amalgamation of various tectonic blocks during the closure of the Paleo-Tethys. During Late Jurassic - Early Cretaceous, accompanied by the closure of the Mongo-Okhotsk ocean, the continent-continent collision gave rise to the formation of the Paleo-Asian continent. Thrust-nappe structures were formed during the intracontinental deformation. At the same time, the Western Pacific Isanagi plate was subducted obliquely, which caused superimposation effect from east to west. In the Middle- Late Cretaceous-Paleogene period, together with the transition from thickened crust to lithospheric thinning and transformation, the intracontinental extensional deformation approached its peak stage. Continental craton basins peneplanes were formed. From Late Eocene to early Miocene (40-23 Ma), the superposition of the motion of the Pacific plate turning in NWW direction, the spreading of the middle oceanic ridges of the Indian Ocean, and the continent-continent collision between the Indian-Australian and the southern part of the paleo-Asian plate induced the formation of the new tectonic landforms in eastern China. Affected by East Asia-Western Pacific riftand the Indian Ocean ridge spreading during Middle Pliocene and early Pleistocene, the eastern China continent experienced lithospheric mantle uplift, crustal thinning, marginal and intracontinental extensional deformation. These processes resulted in the successive formation of marginal seas, island arc, rift basins and eroded highland landscapes. During Early Pleistocene (0.9-0.8 Ma) - Late Pleistocene (0.01 Ma) period, the tectonic landforms of Eastern China were finally formed.

Abstract:Abstract:The subsalt oilfield has distinctive features of a biogenetic origin and is a new field for exploring oil and gas. There are three key problems in the exploration of subsalt oilfields, i.e., new geological concept, applying reverse time migration in seismic data processing and special techniques in drilling. As 90% of oil fields coexist with salt, salt might be a prospecting indicator for the oil and gas field. Precise imaging of salt using reverse time migration can improve successful rate for exploration of subsalt oilfields, and at the same time it can get precious information concerning salt. The exploration of oil and salt at the same time seems to be an effective policy.

Abstract:Abstract:In this paper, the authors studied the intrusive rocks widely distributed in Carboniferous - Permian strata in Maiba area of Xainza County within northern Middle Gangdise belt, and obtained the LA-ICP-MS zircon U-Pb age of 110.8±0.9 Ma for graniteand age of 111.0±1.1 Ma for quartz monzonite, respectively. Both ages are consistent within the error range, suggesting that the granite and the quartz monzonite should be the product of the same magmatic activity. The intrusive rocks are characterized by highSiO2, supersaturated aluminum (A/CNK=1.05-1.38), and enrichment of Al, Th, LREE, with Th abundance being 14.8×10-6-28.4×10–6, implying that they are probably associated with the upper crust substances. Their cobweb curve is remarkably similar to that of the upper crust and acidic volcanic rocks resulting from crustal remelting of 110 Ma Zenong Group in Middle Gangdise belt. These data indicate that the intrusive rocks might be the remelting products caused by the dehydration of crustal materials.

Abstract:Abstract:The Xitian pluton area is located in the middle segment of the Nanling Mountains, and the Yanshanian granites mainly consist of porphyritic biotite monzogranites with many dark microgranular enclaves. These dark microgranular enclaves have plasticshape and magmatic structure, quench boundary, reverse veins and unbalanced textures, such as acicular apatite, quartz ocellar texture and K- feldspar zoning. These characteristics indicate magma mixing. Geochemically, these enclaves are poor in SiO2 and ALK, and the values of K, Fe, Mg, Ca and Ti in the enclave samples are higher than those in their host granites. The enclaves and their host rocks are rich in LREE, with LREE/HREE ratios ranging from 2.6 to 8.8, and display moderate to strong negative europium anomalies (δEu=0.09-0.74). The selected major oxides of enclaves and porphyritic biotite granite show a linear correlation in Harker diagrams. The enclaves and their host rocks display obvious features of magma mixing in the Co variant diagrams. The TFeO-MgO discrimination diagrams also suggest the magma mixing origin of the enclaves. The petrography and geochemistry also indicate magma mixing. The enclaves from the Xitian pluton were probably derived from quenching of mafic magma during its intrusion into felsic magma. The LA-ICP-MS single-zircons U-Pb dating demonstrate that the magmatic age is (150.04±0.52) Ma for the biotite monzogranites and (145.09±0.63) Ma for the enclave. The two ages are basically the same, suggesting that the mixingevent took place during the period of Late Jurassic.

Abstract:The Jiguanshan Mo deposit is one of the important and large Mo deposits in the Xar Moron molybdenum metallogenic belt. Through studying the petrographic and geochemical characteristics of ore- bearing rocks in the Jiguanshan porphyry molybdenum deposit, the authors have found that the rocks are mainly granite, rhyolite, rhyolite porphyry, trachyte andesite, trachyte porphyry and diabase. They belong to high-K calc-alkaline series and shoshonitic series, and lie between the metaluminous field and the peraluminous field. Rare earth elements of samples show a distribution pattern of LREE enrichment, with LREE/HREE ratios being 3.94~7.87 and (La/Yb)N ratios 3.59~8.19. Except diabase, all the rocks show the loss of europium(δEu=0.10~0.68).Trace elements spider diagram of samples shows the enrichment of large ion lithophile elements and depletion of high field strength elements. According to the geochemical characteristics of ore-bearing rocks, the authors infer that the magmatic source region of intermediate and acidic rocks was the crust, there probably existed fractional crystallization in magma evolution, and the evolution process might have included the fractional crystallization of apatite and biotite, or the differentiation of hydrothermal solution of phosphorus with rich volatile matter. In combination with regional geological evolution and metallogenic characteristics of the porphyry molybdenum deposit, the authors hold that the deposit was formed in an extensional environment after the strong extrusion stage of Yanshanian movement, or resulted from the " creeping " and " stretching " process of East Asia continental crust.

Abstract:Pashtok intrusive sequence, located in the southwestern margin of the Tarim Block and the northern margin of the West Kunlun orogenic belt, is composed of quartz diorite and quartz monzonitic diorite, which is similar to TTG combination. It was formed in the late Mesoproterozoic. Large quantities of data prove that the strata and rocks located in the northern edge of West Kunlun orogenic belt still retain the records of orogenic events, plate subduction and convergence at the end of Mesoproterozoic, and they confirm that late Mesoproterozoic southwestern Tarim paleoplate belongs to the present active continental margin. Tarim ancient block was a part of Rodinia supercontinent. The early Paleozoic closure of the Kuda Ocean was closely related to the subduction between Kuda crust and Tarim ancient block. At the beginning of geochemical analysis, main elements and trace elements of Pashtok intrusive sequence were studied in detail. A discussion was made concerning the genesis of the intrusive sequence, the tectonic setting and the geodynamic model between plates around the intrusive sequence. The research shows that Pashtok intrusive sequence is of the I-type metaluminous high-K calc-alkaline granodiorite series, which belongs to continental arc granitoids of active continental margin. The intrusive sequence is divided into two intrusive periods. Both periods of intrusive rocks experienced comagmatic evolution, and the parental magma was a mixture of crustal materials and mantle magma, which gradually evolved into more acidic magma. Based on physical environment and tectonic setting in the course of magmatic evolution, the authors have reached the conclusion that the subduction of the Kuda Ocean crust brought about the closure of the Kuda Ocean and the convergence between Tarim ancient block and Qaidam ancient block which were pieced together and gradually became a part of the Rodinia supercontinent.

Abstract:The Dushan complex consists of granitic rocks with different lithologic types, which are fine-grained quartz monzonite, medium-fine-grained biotite monzogranite and coarse-medium-grained biotite syenogranite. Previous chronological data indicate that the emplacements of these rocks were almost synchronous. Through field work and indoor research, the authors have concluded that this complex was a product of comagmatic evolution. Geochemically, the Dushan complex shows high- silica (69.90% on average), high-aluminum (14.82% on average), low-magnesia (1.09% on average), high-strontium (917.18 μg/g on average), lowyttrium (5.44 μg/g on average), low- ytterbium (0.50 μg/g on average), (La/Yb)N higher than 1 (50.95 on average) and negatively abnormal Nb/Ta. Features of plots on the Sr/Y-Y and Sr/Yb-Yb discrimination diagrams show that they are adakitic rocks. Strong Nb-Ta negative anomaly in samples implies that the Dushan complex may inherit the characteristics of protoliths which are possibly TTGs in this region. Although some metabasaltic and metasedimentary components were involved in protoliths, the TTGs might be the most important. Through geochemical analysis, the strong Nb/Ta anomaly, high (La/Yb)N and high Sr as well as inconspicuous Eu anomaly indicate that the residual mineral assemblages were amphibole + garnet ± plagioclase, and the residual phase was amphibole eclogite facies without rutile. The estimated thickness of the crust was 50~70 km, which in turn reflected the height of the paleomountains of 3000~5000 m. In the light of data of other batholiths in the region, the authors have concluded that the orogenesis between Siberia plate and Sino- Korean paleoplate was occurring during mid- late Triassic. At that time, towering mountain chains appeared in the northeast margin of North China Craton.

Abstract:Based on core observation, thin section identification, diagenetic porosity evolution and studies of burial history relationship, the authors analyzed the origin and evolution of gypsum- salt rock microfacies of Leikoupo Formation in central Sichuan basin and investigated the controlling role and influence of gypsum-salt rocks on the reservoir of Leikoupo Formation in the aspects of sedimentary facies, diagenetic process, and tectonization. It is shown that the gypsum- salt rocks in central Sichuan basin were formed in a limited tidal flat environment of epicontinental sea, which included gypsum-halite pond of supratidal zone, gypsum- halite lake of intertidal zone and gypsum- halite basin microfacies of limited subtidal zone. Its origin included the concentration of the supratidal zone shallow dense brine in low areas, and the sinking and replacement of superficial dense brine produced in the intertidal-subtidal zone. The distribution of gypsum-salt rocks was related to the deposit center migration resulting from rising and falling of the sea level, and also had something to do with the distribution of the point beach. The formation of gypsum- salt rocks, the dissolution effects in the contemporaneous-penecontemporary period, the supergene period karst collapse and the medium-deep burial period dissolution generated by thermochemical sulfate reduction (TSR) all had important contribution to the formation and control of the upper reservoir in Leikoupo Formation in central Sichuan basin. In addition, gypsum-salt rock diapir as cracks and fractures generated by tectonic movements played a certain role in promoting the migration of hydrocarbon source and the redistribution of the gas reservoir.

Abstract:Based on classification of shell ornaments and shapes of ostracods from the Qingshankou Formation to the 1st Member of the Nenjiang Formation in Songliao Basin, the authors studied the possible living environment of ostracods and variation characteristics of 12 types of ostracoda shell ornaments and 9 types of ostracoda shell shapes in the above strata. Studies show that, in the Late Cretaceous in Songliao Basin, ostracods with spinalis ornament were adapted to a deep or semi-deep lake; the species with nubble ornament preferred to live in clean, high pH value and high mineralized semi-deep or deep lakes, the species with deep alveoli, ornamental edge, long nubble or hunch were concentrated in deep or semi- deep lakes, and those with shallow alveoli, reticulation, veins, narrow hunch lived in the shore or shallow lake. It has also been found that the species with a triangular or rectangular shell were abundant in a deep or semi-deep lake; those with low trapezia or pentagonal shells lived in a deep, semi-deep or shallow lake, those with high trapezia shells lived in shallow water, those with ovoid shells lived in a shallow or shore lake, and those with reniform shells lived in a semi-deep or shallow lake. The ostracods in the 1st Member of Qingshankou Formation are dominated by individuals with ornamental edge and pentagon shells. Although shell ornaments and shapes of ostracods are varied in the 2nd and 3rd Members of Qingshankou Formation, they keep a corresponding relationship with the change of depositional environment in the lake. The ostracods in the Yaojia Formation are dominated by individuals with shallow alveoli and vein ornaments and ovoid shells, but a few individuals with deep alveoli ornaments and triangular and rectangular shells appear in the upper Yaojia Formation with the increasing depth of the lake. Although very few types of ostracoda ornaments are known in the 1st Member of Nenjiang Formation and dominated by deep and shallow alveoli ornaments, comparatively varied types of shell shapes are present in this member, such as ovoid, long reniform, rectangular, triangular and trapezia shells.

Abstract:Pingxiang-Yichun area is located in western Pingxiang-Leping depression, where the Early Triassic strata are developed extensively. The stratigraphic nomenclature, age, distribution, and the classification of the stratigraphic units in this area have been controversial for a long time, which considerably hinders the study of the Pingxiang-Leping depression. Through a 1:50000 regional geological survey in Pingxiang - Yichun area , the authors systematically classified the Early Triassic strata of that area for the first time on the basis of investigating lithostratigraphy and biostratigraphy. The Early Triassic strata in the area can be divided in upward sucession into Yinkeng, Qinglong and Zhouchongcun Formations, and the Zhouchongcun Formation can be further subdivided into four members. On the basis of conodont data, the Yinkeng Formation, the Qinglong Formation, and the first member of the Zhouchongcun Formation are assigned to India Stage, and the second member to the fourth member of the Zhouchongcun Formation are assigned to Olenekian Stage. At the same time, according to the characteristics of the lithologic association and sedimentary facies, an analysis of the sedimentary environment was carried out. The sedimentary environment of the Early Triassic strata in the study area was "terrace-continental slope-basin" epicontinental sea with the ancient landform structure.

Abstract:The first member of the Quemo Co Formation in the Woruo Mountain area of the North Qiangtang Basin is mainly composed of purplish red pebbly sandstone, medium to fine sandstone, and argillaceous siltstone, deposited in an oxidation environment. The lithologic characters, sedimentary structures, probability cumulative grain size curves, Sahu formula, grain- size parameters scattergram, and C-M pattern of the sandstones of the first member of the Quemo Co Formation all show that the sandstones are of bad sorting, and the frequency histogram is bimodal or multimodal, the probability cumulative curve of the sandstones mostly represents two-stage and a few three-stage, the percentage of the traction populations is high, and the percentage of the saltation and suspension populations is relatively low. In the Sk-σi diagram, the sandstones of the first member of the Quemo Co Formation fall into the river sand area. Its C-M pattern has the typical feature of fluvial deposit, with the PQ section richly developed but the QR section poorly developed. The deposition of the Quemo Co Formation started with fluvial-alluvial facies, and then these strata were overlain by delta and restricted platform deposition, thus overall displaying a deepening-upward transgressive sequence.

Abstract:Using the high resolution sequence stratigraphy and the correlation analysis of cores, logs and seismic data, the authors identified various stratigraphic sequence interfaces in Lingshui Formation of Qiongdongnan Basin, built the stratigraphic framework, and discussed the sedimentary facies types and the evolution and distribution of the framework, and forecast the distribution of favorable sedimentary reservoirs. The results show that the recognition criteria of stratigraphic sequence interface seem to be the significant changes of lithology and color. The Lingshui Formation of Qiongdongnan Basin is divided into threeorder strata sequences (Els1, Els2, and Els3). Five types of sedimentary facies are developed in this three sets of third- order sequences, which include braided river delta, fan delta, littoral area, continental shelf and carbonate platform.

Abstract:With the methods of rock section, cast section, scanning electron microscope, pressured mercury testing data we made a deep research of the Zhiluo oilfield Chang 8 reservoir's lithology, physical properties, pore throat structure and pore throat types in the paper. This study trying to make a clear inquiry of this area's reserve property and which lay a significant foundation for the further work. The result defines the Chang 8 reservoir, deposited in subaquatic distributary channels, are mainly made up of feldspathic sandstone, debris- feldspathic sandstone. With interparticle pore, intragranular dissolved pore and intercrystal pore, the reservoir is characterized by low compositional maturity and middle texture maturity, which had a poor physical property and it is typical low porosity and low permeability reservoir. In the plane, the reservoirs' physical property is controlled by provenance and sedi- mentary face zones, in vertical direction, the compaction and cementation lead poor reservoir's physical property and dissolution is favorable to reservoir property.

Abstract:Fan delta sediments are well developed in Badaowan Formation along Sikeshu section in Southern Junggar Basin. Two long-term base-level cycles were identified in Badaowan Formation, which can also be subdivided into three medium-term cycles. Based on the dissection of outcrops, the authors divided fan delta sand bodies into three types, i.e., superposition, transitional and isolation types, corresponding respectively to the genesis of braided channel, transformation of braided channel to distributary channel, and distributary channel. The width, thickness and width- to- thickness ratio decrease from superposed to isolated sand bodies gradually. The characteristics, formation, and variation of sand bodies are controlled by the variation and the relevant position. Superposed, transitional and isolated sand bodies are developed under the conditions of low, middle, and high A/S ratios. Furthermore, the dimension of sand bodies is in inverse proportion to the A/S ratio, i.e., the dimensions decrease with the increase of the A/S ratio. With the rise of base level, the proportion, thickness, interconnection, grain size and dimension (width-to-thickness ratio) of channel sand bodies and paleosols decrease accordingly.

Abstract:According to the "sag-wide oil-bearing theory" for the hydrocarbon-rich depression, the lithologic reservoir exploration near the sags has currently become the focus in the exploration work in Dongpu depression and other hydrocarbon-rich depressions of Bohai Bay basin. Paleogeomorphologic analysis makes up the foundation for accurate prediction of deep reservoirs,while favorable sedimentary facies with good tectonic background constitute the key to successful exploration. Based on the technology of basin modeling, the authors reconstructed the paleogeomorphology of Middle Es3 Formation in Pucheng area, Dongpu Depression. Through core observation, thin section identification, grain size analysis,sand ratios and seismic attributes research, the sedimentary facies types were established and their relationships with paleogeomorphology were studied in detail. The results show that the sedimentary systems in the study area were fan delta,lacustrine mudstone and beach bar facies, which were controlled by Paleogeomorphology. There were two gullies on the uplifted side of Lanliao fault and two fan deltas on the downthrown side, assuming a gully-fan corresponding relation. In Pucheng anticline belt, two paleo low uplifts were developed during the formation of Middle Es3, which were surrounded by thicker sandstone, with the sedimentary facies being beach bar. The fan delta front and the beach bar between the two fan deltas in the slope area are favorable exploration areas because upward dipping wedge-out reservoirs and lenticular reservoirs are likely to have been formed in these areas.

Abstract:Multilayer dark mudstone is developed in Jurassic strata of the Muli depression within southern Qilian basin. The evaluation of the source rock of Well DK-3 in the aspects of organic matter abundance,organic matter type, and organic matter maturity indicates that organic matter is abundant, organic matter type is Ⅱ1-Ⅱ2, and organic matter maturity is high. The highest hydrocarbon generation potential layer of the source rock is developed in the depth of 140-350 m, which is black deep lacustrine facies mudstone. The relatively high hydrocarbon generation potential layer is developed in the depth of 630-720 m, which is gray mudstone interlayer from the meandering river. Other layers are low in organic matter abundance and have low hydrocarbon generation potential.

Abstract:Located in the Qimantag metallogenic subzone and monoblock exploration area, the Hutouya polymetallic ore field belongs to the west segment of East Kunlun Mountains. Based on field investigation of structures and multiple-information analysis as well as previous research results obtained in the ore field, the authors summarized main characteristics of ore- controlling structures, discussed the ore-forming geological conditions from the angle of ore field structure,and analyzed the influence of the nearly EW- , NE- and NWW-trending fractures on the ore belt. The difference between structures of various orders was analyzed in the aspect of their roles in mineralization. Some conclusions have been reached based on a comprehensive analysis: ① Nearly EW, NE- and NWW- striking fractures constitute the main ore- controlling structure and control the spatial distribution of the ore deposits; ② Nearly EW-, NE- and NWW-striking secondary fractures and intrusive contacts belong to the metallogenic epoch and control the distribution of Fe-Cu polymetallic ore bodies; ③ Ore bodies were reformed by NE- and nearly SN-striking fractures; ④ Since the Indosinian period,there have been skarnization mineralization stage and hydrothermal reformation stage related to faultfractures; ⑤ As for ore- searching directions, the intrusive contact structure, the nearly EW- trending faulted structures, the intersections of faults and the contact areas between different lithological characters are favorable metallogenic areas.

Abstract:Dolomite is a host rock in the Huize superlarge lead-zinc deposit. The near-ore dolomite shows zonation in space and can be divided into three types, namely grayish white-white coarse-grained (pinhole) dolomite, beige (local miarolitic cavitiy) coarsegrained dolomite and pale red-red coarse grained crystalline dolomite. The authors analyzed the mineral assemblage zonation and fabric characteristics, and reached the conclusion that there exist significant differences between these types of dolomite in such aspects as the degree of recrystallization in dolomite, microstructure of dolomite, crystalline form of pyrite, vuggy fillings and fissures, and these differences can serve as important indicators for identifying ore- bearing dolomite. The authors also studied element geochemistry of near-ore dolomite and other three types of dolomites in Baizuo Formation (mineralized dolomite, coarsegrained dolomite, and dolomitic limestone). According to the relationships between major element content of dolomites and the distance from the ore body and between major element content of dolomites and CaO content, the authors investigated the alteration of rocks and determined the hydrothermal alteration parameters of the coarse-grained dolomites, which are SiO2, MgO /CaO, K2O / CaO and Al2O3/TFe2O3.

Abstract:There are extensively- distributed tungsten and tungsten - polymetallic ore deposits (ore spots) in southern Hunan characterized by complex types. Besides being directly related to granitic intrusive bodies, they are controlled by such factors as regional strata and geological structures. The authors sum up the metallogenic regularity of regional ore deposits on the basis of studying geological background, distribution characteristics and ore deposit features.

Abstract:The results of regional geochemical survey show that selenium content of topsoil is 0.34 mg/kg, which indicates that the soil in the study area is selenium-sufficient or selenium-rich. The results also show that the content of heavy metals in soil is at a safe level. Geochemical anomaly inspection reveals that the Se- rich bedrock controls the distribution of Se- rich soils. There are many kinds of selenium-rich and high-quality agricultural products in the study area, such as selenium-rich rice and soybean, with the proportion of the selenium-enriched soybean reaching 100%. There is a significant positive correlation between plant available selenium and total selenium, and a remarkable correlation between plant available selenium and soil CEC, N and P; the clay minerals and organic matters in soils have a strong adsorption and solidification function for selenium. The available selenium mainly exists in the form of selenite. The biological enrichment coefficients of selenium show a significant negative correlation with soil total selenium and nitrogen but a positive correlation with K2O.

Abstract:Regional geochemical prospecting results in eastern Qimantag of East Kunlun show that, in the near-surface geological body, Na2O, K2O, Sn, W, Bi, Be, U, Al2O3, Ba, SiO2, Pb and Th are relatively abundant, with Au, Bi, Sn, Nb, Pb and F being the main metallogenic elements. Based on anomaly investigation, the authors discovered several ore deposits such as Baiganhu W-Sn deposit, Panlongfeng Fe polymetallic deposit, and Weibao Pb- Zn deposit. In this area, the ore- forming activities of high temperature elements represented by W and Sn were related closely to Variscan and Caledonian magmatic intrusive activities, the ore-forming activities of mid-high temperature elements such as Cu, Pb, Zn and Mo were intimately related to Indo-Chinese acid-intermediate magmatic intrusive activities, the stratabound transformed Pb, Zn ore deposits were connected to the ore-bearing formation of fine clastic rocks-carbonate rocks of Langyashan Group, and the mineralization of Au was related to Yanshanian magmatism.

Abstract:Samples of atmospheric dust- falls and pollution end- members were collected in the urban area of Jinan City. The characteristics of element content in atmospheric dust- falls and pollution end- members were systematically analyzed, and the spatial distribution of atmospheric dust- falls and their pollution sources were studied. The results show that the concentrations of elements vary obviously in different pollution end- members. A comparative study of the concentrations of elements in different pollution end-members shows that the As, Cd, F, Pb content in coal dust are over 3 times that in vehicle exhaust dust, and 1.26- 2.35 times that in street dust, smelt dust, building dust and other pollution end- members, thus greatly affecting the environment quality. The concentrations of Cr, Ni, S, Zn in vehicle exhausts are the highest, those of Co, Ni, Pb, F in smelt dust are somewhat higher, whereas the concentrations of most elements in building dust are the lowest. Compared with the background values of soil, the concentrations of Cr, Cu, Pb, Zn, Cd, F, S in atmospheric dust-falls of Jinan city are slightly higher. These data show that the atmospheric dust- falls are polluted by human activities in different degrees. The coefficient and factor analysis suggests that, in atmospheric dust-falls, Cd, Cu, Hg, Pb, As mainly come from enterprise coal consumption, the values of these four elements near chemical factories, steel plants and smeltery plants are generally high, which is consistent with the spatial distribution of the coal pollution sources. F and S might be related to vehicle exhausts, while As and Cr mainly come from traffic discharges. These three kinds of dusts (coal consumption, vehicle exhausts and traffic discharges) are the main pollution sources of atmospheric dust-falls in Jinan City, with the contribution proportion of atmospheric dust- falls up to 60.42%. Studies reveal that industrial coal emissions have gradually replaced the vehicle exhausts and become a major source of Pb in atmospheric dust-falls.

Abstract:In southwest Shandong Province, high fluorosis in drinking water caused by high fluoride groundwater seriously affects the health and well-being of local people. Fluorine concentration in groundwater is a very complex hydrological and geochemical process. Water chemical test results indicate that fluoride content is 0.05~6.7 mg/L, 1.20 mg/L on average, and high-fluorine areas are mainly distributed in the juncture between the Jiaxiang Yellow River alluvial-pluvial plain and piedmont alluvial-pluvial plain as well as the interstream depression of the Yellow River alluvial- pluvial plain in Caoxian County, Shanxian County and Heze. Fluorite content of the groundwater has no distinct relationship with pH and mineralization intensity but is positively and negatively correlated with relative values of K++Na+ and Ca2+ respectively and obviously correlated with Ca2+ content. The authors probed into the hydrogeochemical genetic mechanism of the shallow-layer high-fluorine groundwater in the aspects of geological environment, hydrogeological environment and hydrogeochemistry, and studied the formation mechanism of the high-fluorine groundwater in the plain formerly flooded by the Yellow River. The results obtained by the authors are of important theoretical and practical significance for determining the cause of the fluorine-related endemic diseases, formulating the measures for prevention and cure of such diseases, and finding low fluorine groundwater suitable for dring.

Abstract:Utilizing 208 surface soil samples collected from the coastal wetlands of Yellow River delta in 2006—2008, the authors studied REE distribution characteristics in wetlands covered by different kinds of vegetation and measured 14 kinds of elements in each sample by ICP-MS method. Some conclusions have been reached: ΣREE content in surface soil of wetlands in upper delta plain is 137.29×10? 6-267.82×10? 6, with an average of 166.73×10? 6; the REE distribution characteristics in sea-blite wetlands are similar to those in bare wetlands; the REE distribution characteristics in reed wetlands are similar to those of China's Tamarisk wetlands, but both of them are lower than the REE distribution characteristics in sea-blite and bare wetlands; the ΣREE content of the surface sediments of wetlands in shallow sea is 143.11×10?6-222.48×10?6, with an average of 180.80×10?6; the distribution curve of REE of wetlands in upper delta plain of the Yellow River is higher than that in shallow sea of the Yellow River; the distribution curve of REE of wetlands in shallow sea of the Yellow River is higher than that in sediments of the Yellow River. LREE has more possibility to participate in the circulation of biogeochemistry than HREE.