Abstract:Abstract：Great progress has been made in regional and national geochemical mapping. How to use extremely low-density sampling to obtain a global picture of the distribution of most elements in the periodic table in the expectable future is an important issue for applied geochemists. This will depend on the innovation of the mapping concept and developments of new sample media, sampling layout and sampling methodology. English geochemists found that the analytic results of stream sediment samples taken from estuaries of catchments covering an area of several to several dozen square kilometers approximate the average values of elements in soils in catchments in the upper reaches of the rivers. This finding has been extended by Norwegian and Chinese geochemists who analyzed samples taken from overbank and floodplain sediments at the estuaries of still larger rivers (whose catchments are several hundred, thousand and even a few dozen thousand square kilometers). Such a new finding is in accordance with the fractal concept, which may be further extended to main estuaries of some catchments with an area up to hundreds of thousands of or over a million square kilometers in the world. However, more research should be carried out. Based on this new mapping concept, a proposal of the project “Global Geochemical Mapping and Sediment-Associated Flux of Major World Rivers” was advanced.

Abstract:Abstract：By using the theory and method of modern structural analysis, the paper analyses the explosion seismic sounding profiling and natural seismic surface wave tomographic imaging in the Koktokay of Xinjiang to Jianyang of Sichuan geoscience transect and integrates the results of research on geology, geochemistry, structural petrology of deep-seated xenoliths and geophysical signs. These studies indicate that the geometric structure pattern of high-speed blocks or mantle block tectonics is one of the basic conditions for controlling the lithospheric tectonic pattern and tectonic deformation of the lithospheric surface. The crustal, lithospheric and asthenospheric velocity structure models and material composition models are constructed in this geoscience transect. Based on a systematic study of the high-speed blocks in the lithosphere, three geometric structures of the lithosphere are distinguished: craton-root-shaped structure, orogen-wedge-shaped structure and plateau-root-shaped structure, and two tectonic evolution types of the lithospheres are recognized: cratonic lithosphere and thickened lithosphere. Based on the aforesaid systematic description, the paper discusses the structural types of the asthenosphere, interaction between the lithosphere and asthenosphere and mantle dynamic model of this geoscience transect.

Abstract:Abstract：The Siling rock mass, which was formerly regarded as typical S-type granites or reworked anatectic granites, should be aluminous A-type granites. This rock mass is rich in silica, alkalis and potassium and distinctively poor in calcium and magnesium; it has high K2O+Na2O/ CaO values (average 16.79) and a high AKI index (average 0.92)；high FeO?鄢/MgO ratios (average 13.95), higher than that of M-type, S-type and I-type granites but close to the average value (13.4) of A-type granites worldwide；the rock is weakly alkaline, metaluminous-weakly peraluminous quality, rich in REE and HFSE , high in Rb, F and Nb, which are also the characteristics of A-type granites. The δ18O values of the Siling rock mass range from +8‰ to +9‰. All these suggest that the magma of the granites was mainly derived from the lower crust. The rock mass was emplaced into an extensional environment, which was an important tectono-magmato-thermal event in the early Late Cretaceous. It also indicates that the regional Xiaofeng-Sanmenwan fault and Xuechuan-Huzhou fault were in their extended stage in the early Late Cretaceous.

Abstract:Abstract：Rapakivi-textured feldspars occur in Late Carboniferous weakly gneissic, medium-grained porphyaceous monzogranite in the Daling area between Hegang and Yichun cities at the southeastern end of the Xiao Hinggan Mountains. Most of them are idiomorphic and broad sheet-like or broad-prismatic in shape, and consist of an alkali feldspar core and a plagioclase mantle. Some are ovoid or globoid in shape without a plagioclase mantle and about 1.5-3.5 cm in size. Their petrographical features are comparable to those of the typical rapakivi granite. In addition, dark-colored microgranular dioritic enclaves are generally developed, and they have close relationship with rapakivi K-feldspars. The enclaves have typical textures of magma and acicular apatites and contain K-feldspar and quartz megacrysts of host rocks. The enclaves are mainly rounded in shape, showing pronounced plastic rheological characters. They usually have a clear-cut contact relationship with the host rocks and sometimes transition or foggy contacts could also be seen. The above-mentioned evidence fully shows that the enclaves are MME type enclaves. On the basis of the geological characteristics of the pluton, rapakivi-textured K-feldspar phenocrysts, dark-colored microgranular dioritic enclaves and petrochemistry and geochemistry, the Daling rapakivi granites were the product of magma mixing and formed in an orogenic environment, and their age and tectonic setting are different from those of typical rapakivi granites.

Abstract:Abstract：Yanshanian mineralized granites in southern Hunan may be divided into three types, which have different REE geochemical features, distribution patterns and characteristics of compositional variations, showing distinct differences in petrogenesis and mineralization. (1) The total REE of MC-type granites is lowest, 225×10-6 on average; the average La/Yb ratio is 17, the average LREE/HREE ratio is 5.4, and δEu is 1.67, all of which are highest. Chondrite-normalized REE patterns are nearly straight lines inclined to the right. The total REE of C-type granites is highest, 353×10-6 on average; the average La/Yb ratio is 4.3, the average LREE/HREE ratio is 1.5, and δEu is 1.67, all of which are lowest. The REE distribution patterns are seagull wing-shaped. CM-type granites are intermediate between MC- and CM-type granites. The distribution patterns of the early-stage CM-type granites incline to the right, while those of the late-stage ones are seagull wing-shaped. (2)With increasing acidity, the ΣREE and REE concentrations increase from MC-type through CM-type to C-type mineralized granites and from the east to late stage of the same type of granite. However, LREE show somewhat depleted slightly and HREE enriched; the δEu, La/Yb and LREE/HREE show significantly antithetic relationships with SiO2；and HREE display a reversed trend of evolution and differentiation with magma evolution. (3)The REE of the late-stage CM-type and C-type granites are remarkably differentiated. The deep Eu troughs of the REE patterns indicate a significant fractional crystallization of CM- and C-type granitic magma, which caused HREE to be enriched and Sn, W, Nb and Pb to be concentrated to form ore deposits. (4)Mineralized granites show features of crust- and mantle-derived melt mixing granites rich in volatiles such as F and Cl, and their formation was related to crust-mantle magma mixing; whereas the magmatic evolution of the late-stage CM-type granites and C-type granites might also involve fractional crystallization.

Abstract:Abstract：Divergent views exist as to whether the Precambrian basement under the Songliao basin exists or not. Older zircons were discovered in a number of samples during the SHRIMP zircon dating of Early Cretaceous volcanic rocks in the northern Songliao basin, and their ages indicate that they mainly formed in the Precambrian. It is suggested that they were probably captured from the basement rocks during Early Cretaceous volcanic eruption. Three age groups have been broadly distinguished for the captured zircons：（1848±34） Ma, （1600±29） Ma and（1293±41） Ma, which implies that the basement of the northern Songliao basin experienced multiple tectono-magmatic events during the Paleo- and Mesoproterozoic. Therefore, it is believed that the Precambrian basement exists under the northern Songliao basin.

Abstract:Abstract：The Xiugugabu ophiolite is situated in the western segment of the Yarlung-Zangbo ophiolite belt, southwestern Tibet, belonging to SSZ-type ophiolites. The crystallization age of gabbro-diabase in the ophiolite was determined using the Sm-Nd method. The internal isochron age of plagioclase, pyroxene and two whole-rock samples is 126.2±9.1 Ma, which represent the time range for the subduction of the Tethys Ocean. In addition, Nd-Sr-Pb analysis of gabbro-diabase indicates that the gabbro-diabase has high initial εNd(t) values (6.7-9.1), suggesting that the primitive magma was derived from a strongly depleted mantle and had not undergone contamination with continental crustal materials. The ophiolite has lower initial 206Pb/204Pb values of 17.412-17.523 but higher 208Pb/204Pb values of 37.352-37.706 and shows higher ISr values of 0.70278-0.70383, indicating that the Xiugugabu ophiolite originated from the Indian MORB mantle domain.

Abstract:Abstract：Mesozoic tectono-magmatism and mineralization in southeastern Hunan in the central segment of the Nanling Mountains have been systematically studied. The following ideas are put forward. (1) The period from the late Middle Triassic to early Middle Jurassic (early Mesozoic) was an intracontinental orogenic stage. The late Middle Triassic witnessed strong intracontinental subduction-convergence in a regional WNW-ESE compressional regime, which resulted in formation of large numbers of E-dipping, NNE-verging thrusts and folds. The formation mechanism of the trough-like folds in an uplift area east of the Chaling-Chenzhou fault were "thick-skinned" rather than "thin-skinned". NW-trending basement hidden faults underwent strong sinistral strike-slip movement under WNW compression, which led the NNE-directed lineament to rotate counterclockwise, thus forming the Anren “y”-type structure and the N-S-trending Shuikoushan-Xianghualing tectonic zone. The strong compression made the crust thicken substantially and caused the temperature of the deep crust rise continuously. In the terminal Middle Triassic-latest Triassic (233-210 Ma), the regional stress weakened, the heated middle crust melted and mantle-derived basic magma underplated; as a result, large-scale granitic magmatism took place in a post-collisional setting. Down-faulted basins formed by syn-orogenic uplift-extension in the terminal Late Triassic-Early Jurassic. Piedmont thrust-compressional basins and thrusts and NW-trending dextral strike-slip faults occurred in a NNE-trending sinistral convergence and strike-slip regime at the beginning of the Middle Jurassic. The dynamic mechanism of early Mesozoic intracontinental orogeny is mainly related to far-field compression effects of plate convergence. (2) The early Middle Jurassic-Cretaceous (late Mesozoic) was a post-orogenic-intracontinental rifting stage. In the early Middle Jurassic-Late Jurassic (174-135 Ma), there occurred large-scale granitic magmatism and mineralization due to lithospheric delamination. The passive emplacement mechanism of the plutons, occurrence of mafic microgranular enclaves, Sr-Nd isotopic features, predominance of high-K calc-alkaline and calc-alkaline rocks in the plutons, geochemical discriminations of structural environment, large-scale nonferrous metal mineralization and tectonic evolution setting suggest a post-orogenic environment in the stage. The Cretaceous was a strong intracontinental extensional stage, when basin-range tectonics and related divergent strike-slip faults formed, various kinds of dikes were widely developed and small AA-type granite bodies and basic volcanic rocks originated locally. Thermochronological data suggest that the evolution of the basin-range tectonics progressed through the tectonic denudation stage and weathering erosion-sedimentation stage. (3) The cause for the fact that the ore-forming capacity of the early Yanshanian granites in southeastern Hunan was far larger than that of the Indosinian granites is mainly attributed to the differences in tectonic setting and tectonic regime. The ore materials in magma of granites could spread and be precipitated more easily in an Early Yanshanian post-orogenic extensional regime; on the contrary, the ore materials were confined in the pluton in an Indosinian post-collisional weakly compressional setting. The second cause of the difference in ore-formation capacity is due to the difference in geochemistry of granites, i.e. the tectono-magmatic evolution and introduction of deep ore-forming fluids caused the early Yanshanian granites to have better ore-forming geochemical conditions than the Indosinian granites. (4) The formation of the W-Sn-polymetallic and Pb-Zn-polymetallic deposit assemblage is probably mainly related to such factors as the structure (or thickness) of the lithosphere, intensity of thermal perturbations in the deep interior of the Earth and corresponding scale of magmatism and depth of pluton emplacement.

Abstract:Abstract：Faults are well developed on the northeast slope of the South China Sea. There are mainly the NE, NW, nearly N-S and nearly E-W sets of faults. According to the fault natures, they can be divided into tensional faults, compressional faults and strike-slip faults. The main basement faults are F1, F2, F3, F4, F5, F6, F7, F8, F9 and F10. Those faults are large in scale and controlled the development and evolution of the Baiyun subbasin of the Zhujiankou basin, Jianfengbei basin, Bijia basin and Taixinan basin. Controlled by main faults, the Jianfengbei basin underwent three stages of evolution: downfaulting, downwarping and subsidence, and two structure layers occurred; the Bijia basin also underwent three stages of evolution：Oligocene downfaulting, late Oligocene to middle Miocene downwarping and late Miocene to Holocene tectonic inversion, which gave rise to two structure layers.

Abstract:Abstract：The formation of a caldera is the most catastrophic volcanic phenomenon leading to the most voluminous pyroclastic eruptions. Therefore, to explore the evidence for the existence of a caldera is the key to the understanding of the characteristics and superimposition relationship of volcanic eruptions in the Lower Cretaceous Yingcheng Formation in the Xujiaweizi fault depression, northern Songliao basin. The Xudong caldera, filled with thick rhyolitic tuff and lava, is a large caldera, ellipse in form with an area of 17 km×10 km and a maximum subsidence depth of 3 km. Its trapdoor subsidence was caused by its underlying asymmetrical magma chamber or asymmetrical deflation of the magma chamber. In section, there is a pair of completely developed normal and reverse faults, indicating that the Xudong caldera experienced a complete process of sinking subsidence, and syn-subsidence volcanic eruption. The caldera is the product of lithosphere thinning and substantial magmatism in a continental rift setting. The N-S-elongated ellipse shape of the caldera was formed under the control of the NNW-trending structures.

Abstract:Abstract：The authors analyzed the residual thicknesses of various Meso-Cenozoic structural layers and sedimentary characteristics in the western Sichuan foreland basin and found the following: The foreland basin at peripheries of the Sichuan craton occurred in the front of the Longmen Mountains during the Late Triassic, evidently belonging to a foredeep formed under the structural loads of the Longmen fold-thrust; in the Early Jurassic sedimentary strata were of areal distribution with no markedly flexural subsidence, indicating a tectonically quiet stage. In the early Middle Jurassic, the foredeeps migrated to the front of the Micang Mountains and the northern segment of the Longmen Mountains and the direction of foredeep sediments changed from northeast in the Late Triassic to nearly E-W then. Widespread lacustrine sediments imply a hungry basin. During the middle-late Middle Jurassic, the subsidence center of the western Sichuan basin migrated to the front of the Daba Mountains, with the direction of the corresponding flexural deformation changing from nearly E-W to NW, forming the Daba foredeep. During the Late Jurassic to Early Cretaceous, the subsidence center again returned to the front the Micang Mountain and very thick foredeep sediments indicate the main period of activities of the Micang thrust belt. Then during the Late Cretaceous to Paleogene, the foredeep jumped to the Ya'an-Mingshan area, southwestern Sichuan. The syn-orogenic subsidence center of the western Sichuan foreland basin migrated in an arcuate form in the western and northern parts with the Sichuan basin as the center, and the sedimentary sequences alternated and were stacked continuously. The contour maps of the bottoms of various Mesozoic structural layers show that the present structure low is located in northwestern and southwestern Sichuan, with E-W-striking contours distributed in northwestern Sichuan and NE-SW-striking contours in southwestern Sichuan. Therefore this paper suggests that Late Jurassic to Early Cretaceous structural deformation might control the present deformation of strata in the western Sichuan basin, forming the N-S tectonic compressional structure in northwestern Sichuan, and that the Cenozoic structural deformation is mainly manifested in the southwestern part of the western Sichuan basin, forming a NE-SW-trending stratigraphic distribution pattern.

Abstract:Abstract：The authors studied the material source, characteristics of sedimentary facies, sand control in the slope-break zone and distribution of Chang 6 sand bodies of the Yanchang Formation of the central Ordos lake basin. The source of sand bodies comes from the northeast and southwest. There are sandstone deposited by deltaic traction current action and turbidite sandstone deposited by gravitational transport. The sedimentary facies include superposed submerged distributary channels, mouth bars, distal bars and turbidite. The direction of distribution of the thick sand bodies is vertical or parallel to the lakeshore line.

Abstract:Abstract：Quaternary land and sea shift and environmental evolution with a relatively long duration on the north flank of the Yangtze River delta are lacking in a deep-going study. A 423 m deep hole, named J9, was drilled in bed rocks at Hai'an County of the Yangtze River delta, which provides a good research target. Based on observations of its core in the loose bed and summarizing the sedimentary characteristics, it is evident that this core may be divided into six characteristic lithological intervals. In addition, the paleomagnetism data of the strata suggest the following： the interval 0-200 m belongs to the Brunhes normal polarity epoch, the interval 200-334 m to the Matuyama reverse polarity epoch, and the interval below 334 m depth to the Gauss normal polarity epoch. Through an integrated analysis of the sedimentary characteristics of the core and by referring to the results of the paleomagnetic measurements, the authors made a preliminary stratigraphic division and think that： the interval 0-39 m is Holocene strata, the interval 39-153 m Late Pleistocene strata, the interval 153-200 m middle Pleistocene strata, the interval 200-334 m early Pleistocene strata and the interval below 334 m depth Neogene strata. There is a late Pleistocene hard clay marker bed, which indicates that the postglacial river valley was not developed in this area.

Abstract:Abstract：The Lingshan intrusion in southern Henan contains abundant mineral resources. The paper discusses the distribution characteristics of uranium mineralization of the intrusion and then elucidates characteristics of uranium mineralization of the intrusion. The uranium mineralization is controlled by structure and fractures and sites favorable to mineralization lie at sites of intersection and compounding of the structural zones and dikes in the intrusion. The zone of mineralization concentration mostly contains iron, manganese and mud and hydrothermal alteration is well developed. The uranium source comes from the intrusion. There are four types of mineralization. The analysis of the mineralization characteristics may guide ore search in the Xinxian and Shangcheng intrusions in southern Henan.

Abstract:Abstracts：The Zengmu basin is a large Cenozoic sedimentary basin located in the southern South China Sea, characterized by a high sedimentation rate and great thickness. Recent petroleum exploration and research indicate that the Zengmu basin has very favorable geological conditions for the formation of petroleum, where there occur mainly two groups of source rocks, including Oligocene paralic carbonaceous shale, coal layers and marine mudstones and lower-middle Miocene marine mudstones, and two types of reservoirs, namely, Oligocene-middle Miocene sandstones and middle-upper Miocene limestone or reef limestone. The Kangxi depression and Eastern Balinjian depression are two primary hydrocarbon-generating zones. Vertically, petroleum mostly occurs in lower Miocene sandstone and middle-upper Miocene carbonates, with the formar mainly containing oil and the latter mainly containing gas. Laterally, the petroleum distribution in the Zengmu Basin is characterized by occurrence of oil in the south and gas in the north. Gas fields are mainly distributed in the Nankan mesa in the east and the western slope, while oil fields mainly occur in the Balinjian area. The distinct zonal distribution of oil and gas is primarily related to structures in different tectonic units and difference in sedimentation in the basin.

Abstract:Abstract：A large tract of Cd-rich soils is found along the lower reaches of the Yangtze River in Jiangsu and the Cd content in vegetable samples is found to be in excess of standards in some areas. Based on a preliminary analysis of the element geochemical characteristics of Cd-rich soils in the study area, the authors discuss the main cause for the local Cd pollution in soils and systematically introduce the main research data and results of heavy metal-polluted soil remediation and control tests performed in vegetable lands polluted by Cd in Baguazhou, Nanjing. It is found that the Cd concentration within vegetable can be significantly reduced by applying an appropriate quantity of fixation agents such as calcium-magnesium phosphate [(Ca, Mg)3(PO4)2] fertilizers. This study provides a new idea for safe vegetable production in areas of relatively Cd-rich soils in the lower reaches of the Yangtze River.

Abstract:Abstract：Investigation and assessments of pollutions of heavy metals such as Cu, Pb, Zn, Cd, Cr, Hg and As in Zhuzhou City were carried out. The results show the following： (1) The Cd pollution of all the 60 samples from Zhuzhou City has been heavy, the pollution of Cu, Hg and As is moderate, and the pollution of Pb, Zn and Cr is slight. The Nemerow comprehensive pollution index also shows heavy pollution. (2) The heavy metal contents in soils of different land use types decrease as follows： the Cu, Zn, and Cr contents decrease from paddy field→vegetable field→dry land; Pb, Hg and As, dry land→paddy field→vegetable field; and Cd, vegetable field→dry land→paddy field. (3) The heavy metals content with different soil types from high to low is as follows： The contents of various heavy metals in different soil types decrease as follows： the contents of Zn, Cd and As decrease from sandy Chao soil→clay soil→red soil; Pb and Hg, clay soil→sandy Chao soil→red soil; Cr, red soil→sandy Chao soil→clay soil; Cu, sandy Chao soil→red soil→clay soil.

Abstract:Abstract:In order to understand the content and origin of iron in groundwater of the Zhujiang delta, the authors took and analyzed 352 groups of groundwater samples and 12 groups of surface water samples. The results show that the iron content in groundwater of the Zhujiang delta range from undetected to 94.8 mg/L with an average of 1.46 mg/L. The distribution of iron content in groundwater of the area is closely related to the extent of industrialization and recharge, runoff, discharge conditions of the Zhujiang delta, especially in the plain area, where the content of iron in groundwater is more closely related to the pollution degree of rivers. The content of iron in groundwater decreased significantly far away from the polluted surface rivers. The factors that play a dominant role in iron content of groundwater are different in different areas of the Zhujiang delta. The redox condition is one of the main factors for affecting the distribution of iron content in groundwater in the Zhujiang delta, while the pH values and ground pollution only play a dominant role in the distribution of iron content in groundwater in some areas of the Zhujiang delta. In addition, such factors as the components of aquifer media, runoff conditions and characteristics of overlying soils all exert a certain effect on the iron content of groundwater in the Zhujiang delta.

Abstract:Abstract：In order to study the environmental geochemical characteristics of urban soils in Qingdao, the authors carried out an extensive soil geological survey in the Shinan, Shibei, Sifang, Licang and Chengyang districts of Qingdao City. A total of 319 surface soil samples (at 0-10 cm depth) were taken with a density of 1 sample per 1 km2. The concentrations of 72 elements in the soil samples were determined with several analytic instruments including XRF, ICP-OES, ICP-MS and so on. This paper only discusses the heavy metals As, Cd, Cr, Cu, Ni, Pb and Zn, as well as the metalloid As. Study indicates that human activities lead to the increase of concentrations of Cd, Cu, Hg, Pb and Zn in topsoils. As, Cr and Ni are mostly of geologic origin, but they are also affected by anthropogenic activity. The concentration of Zn varies more greatly than those of other elements. The increase of Zn concentrations is caused by heavy industrial operations and traffic in areas where human activities are frequent.

Abstract:Abstract：The paper summarizes the metallogenic characteristics in Chifeng. Under the guidance of the theory of mineralization caused by geological anomalies, the authors extracted ore search information from geological, geophysical, geochemical and remote sensing data in Chifeng using the GIS technique and carried out metallogenic prediction using the weight of evidence method. On that basis, Qibov's law was adopted to estimate the gold resources. The results show that there are three NE-striking favorable metallogenic belts in the north of Chifeng, one NW-striking favorable metallogenic belt in the Tuchengzi Township-Jinchanggouliang Township in the south and three good ore prospect areas at peripheries of Laofu Township, in Harqin Qi and Balihan Township. The total gold resources are～181 tons. When 76 tons of identified is subtracted, there are still 105 tons of potential gold resources in Chifeng.

Abstract:Abstract：The leaching pretreatment of refractory gold ores by bacteria has advantages of lower operating costs, less environmental pollution and higher efficiency of treatment. So it is considered to be a promising effective method for pretreatment of refractory gold ores. In this study, samples were taken from the Huashiyou gold deposit, Zunhua, Hebei. The samples are refractory ore, a kind of pyrite containing gold. Several strains of Thiobacillus ferrooxidans were used in pretreatment of the samples. Among those, D3 strain was found to decompose sulfide ores effectively. If the size of the ore is 200-mesh, the cyanidation rate of gold rises from 63.9 (without biooxidation ) to 88.2% (after biooxidation). For gold ore with a grain size < 100 mesh, the cyanidation rate of gold may also generally rises >10%. In addition, some conditional experiments for the process of treatment of gold ore by this strain were also performed; for example, the size influence, pH change and strengthening of the physical method were studied. Some rules in the biooxidation process of gold ore and the optimum controlling conditions during practical operations were obtained from the experimental results.