Abstract:Abstract：Paleozoic tectonics and endogenic metallogeny in Tianshan-Altay area of Central Asia constitute an important research topic in geology. The Altay area, as a collision zone of the Early Paleozoic (500-397 Ma), and the Tianshan region, as a collision zone of the early period in Late Paleozoic (Late Devonian - Early Carboniferous, 385-323 Ma), resulted from nearly NS-trending shortening and collision（according to recent magnetic orientation）. In the Late Devonian-Early Carboniferous (385-323 Ma), regional NW-trending faults exhibited features of the dextral strike-slip motion in Altay area and Junggar basin. In the Tianshan area, however, nearly EW-trending regional faults caused motions of the thrusts, thus belonging to the collision period of the Tianshan Mountains. However, in the Late Carboniferous-Permian (323-260 Ma), these areas suffered from weaker eastward compression, influenced by the long-distance effect of the Ural collision zone, which converted existent NW-trending faults into sinistral strike-slip in Altay and Junggar areas, and also converted existent nearly EW-trending faults into dextral strike-slip in Tianshan area. The rocks of that area in the Late Carboniferous - Permian period were moderately ruptured into a certain tension-shear form, thus forming a number of world-famous giant endogenic metal ore deposits in Tianshan-Altay area. As to the Central Asian continent, the most powerful collision period may not coincide with the most favorable endogenic metallogenic period. Therefore the “orogenic metallogeny hypothesis” should be treated with caution in that area.

Abstract:Abstract: Located in the northeast Darbute ophiolitic mélange, West Junggar, Xinjiang, the Muhatayi ophiolitic mélange consists mainly of harzburgite with serpentinization and silica-carbonate alteration, basalt and chert, together with some intrusive gabbro veins. In this study, petrographic and geochemical analysis, U-Pb dating and Hf isotope study were conducted for ophiolitic mélange. Both of basalt and gabbro in ophiolitic mélange belong to low-potassium tholeiitic series, display typical characteristics of E-MORB and N-MORB, and are enriched in LILE (Ba, U, K, La, Ce) and depleted in HFSE（Nb, Ta,Th）. In combination with the discrimination diagrams of immobile trace elements and oxides, the authors hold that the Muhatayi ophiolitic mélange was produced in an arc-basin setting. The LA-ICP-MS U-Pb isotope dating of zircons from basalt yielded an age of (392.5 ± 2.9) Ma（n=26，MSWD=1.3）, which represents the age of ophiolitic mélange. εHf (t) values of zircons range from +12.2 to +15.1 and t(DM)（407-543 Ma）values are close to the ages of zircons, which indicates that the basaltic magmas were derived from depleted mantle without crustal contamination. The chemical composition of Cr-spinel of harzburgite and the Dy/Yb versus La/Yb of basalt reveal that the harzburgite was the residual after the 25%-30% partial melting of depleted spinel-lherzolite, the mafic melt was the parental magmas of basalt and gabbro. It is thus considered that the west Junggar Basin represented by Darbute ophiolitic mélange was developed in an arc-basin setting resulting from the northwestward subduction of Junggar Ocean，the west Junggar Ocean was spread before Middle Silurian and remained existent in early Carboniferous, and then the oceanic basin experienced the stage of subdution and closure.

Abstract:Abstract: The Hongliugou copper-nickel mineralized mafic-ultramafic rock is located in the Beishan rift belt on the northern margin of the Tarim plate. There are two regional deep fracture zones in the rock on both sides, i.e., Dashantou-Gangliunaozi and Fangshankou-Miaomiaojing-Shuangyingshan. Rock mass was emplaced in the the Dunhuang rock group, copper-nickel mineralization usually occurs in lherzolite, whereas olivine two-pyroxene monzonite and olivine norite-gabbro. SHRIMP U-Pb dating of zircon from the olivine hornblende gabbro norite yielded an age of (396.7±3.8) Ma, which suggests that both the intrusion of the ore-bearing complex and the mineralization occurred in middle Devonian. Combined with the age of Heishan and Guaishishan copper-nickel ore-bearing rock, it is revealed that Beishan area of Gansu was in a continental margin rift extensional environment in the middle-Late Devonian.

Abstract:Abstract: Located in western Central Qilian Mountain, the Yemashan batholiths are composed of early pluton (granodiorite and porphyritic monzogranite) and late pluton (monzogranite). U-Pb age determination of zircon by LA-ICPMS shows that the early pluton of Yemashan batholiths was intruded at (469.0±1.3) Ma, and the late pluton was intruded at (450.0±1.0) Ma. Compositionally, the early pluton of Yemashan batholiths has SiO2 values ranging from 59.8% to 64.2%, K2O/Na2O ratios higher than 1, and molar A/NKC ratios from 0.8 to 1.0, indicating typical metaluminous granitoid. The pluton is depleted in Ba, Nb, Ta, Sr, P and Ti, and enriched in Rb, U and Th, and has total REE content ranging from 97.73×10-6 to 185.76×10-6, (La/Yb)N from 5.57 to 12.47, and LREE/HREE from 7.7 to 11.3. The chondrite-normalized REE patterns of the pluton exhibit enrichment of LREE and depletion of HREE, with moderate negative Eu anomalies (δEu=0.66-0.89). The late pluton of Yemashan batholiths has SiO2 ranging from 69.8% to 76.5%, K2O/Na2O from 1.2 to 1.7, and molar A/NKC from 0.8 to 1.0, implying weakly peraluminous granitoid. It also shows enrichment of Rb, U and Th, and depletion of Ba, Nb, Ta, Sr, P and Ti, with ∑REE from 78.97×10-6 to 244.92×10-6, and (La/Yb)N from 5.57 to 12.47. The chondrite-normalized REE patterns of the pluton exhibit enrichment of LREE and depletion of HREE, with pronounced negative Eu anomalies (δEu=0.11-0.24). The petrological and geochemical characteristics indicate that the early pluton of Yemashan batholiths could represent typical I-type granite formed in a subduction orogenic setting. The late pluton should be assigned to highly fractionated I-type granite formed in a post-collisional orogenic setting. On the basis of these features in combination with the tectonic locations of granite occurrence and field observation data, the authors hold that southward and northward subductions of the North Qilian oceanic plate took place in the Early Paleozoic, during which the southward subduction and collision resulted in the formation of Yemashan batholiths.

Abstract:Abstract: The rock association of the Daoxiang Formation which occurs in Xingxi, Daoxiang and Tieshan area of Zhenghe County is very complex and comprises volcanic rocks, sedimentary rocks and metamorphic rocks. The geological age of the Daoxiang Formation remains unclear. The Daoxiang Formation is now divided into three suites of lithologic association which belongs to different geological ages. The upper and middle segment of Daoxiang Formation belongs to late Proterozoic and Early Jurassic respectively. The lower segment of the rock association which is regarded as the combination of silicolite-mudstone-siltstone-volcanic rocks was formed at the late period of Early Cretaceous according to the zircon LA-ICP-MS U-Pb dating of vesicular basalt and silicified mudstone, and its diagenetic environment is similar to that of the Shimaoshan Group.

Abstract:Abstract: Suhongtu Depression in Inggen-Ejin Banner basin is located on the northwestern margin of the North China Craton. The periphery of the North China Craton is a weak tectonic belt, with Hing - Mongolian orogenic zone on the northern margin, Dabie - Qinling orogenic belt on the southern margin, Tan-Lu fracture zone and Pacific subduction zone on the eastern margin. Hetao rift and Fenwei rift are roughly coincident with positions of Paleoproterozoic high-temperature metamorphic rocks and the central orogenic belts, which were formed during the breakup period of the North China Craton and western blocks approximately 1.85 billion years ago. However, Suhongtu Depression is located on the southern edge of the Central Asia Orogenic Belt, and also lies at the junction of two plates. These structural weakness belts experienced subduction in different periods, and might have served as the starting locations of lithospheric thinning, and the time of their subduction and collision was the beginning of the destruction of the North China Craton. Craton destruction regions occurred mainly to the east of the Taihang Mountains, whereas thinning happened in Fenwei rift, Hetao rift and Suhongtu Depression west of the Taihang Mountains. Therefore, damages to the Suhongtu Depression lithosphere occurred on the northwest margin of the North China Craton in the late Early Cretaceous (~ 110Ma), and hence the damaged regions in the Craton were distributed discontinuously in geography, which resulted from different destruction periods and dynamic mechanisms of the lithosphere in different regions.

Abstract:Abstract: Located in the suture zone of the Cathaysia and Yangtze tectonic belt and lies on the southern side of Jiangshao fault, the Xiangshan uranium orefield is the largest volcanic uranium orefield and is also the earliest discovered volcanic uranium orefield in China. Its basement is a set of ancient metamorphic rock series. Micro palaeophyte fossils and previous studies indicate that the basement metamorphic rocks formed in the Qingbaikou period of Neoproterozoic. This paper mainly discusses the composition of metamorphic rock and analyzes its formation environment. Most metamorphic samples are characterized by intermediate SiO2 content, high K2O/Na2O and Fe2O3T+MgO, and obviously low CaO content. Analytical results of all samples show larger total ΣREE values and abundant LREE, as well as depletion of Eu, implying that the rock samples originated from the continental crust. The overall compositions of various sample patterns are very close to each other in the REE distribution diagram, and REE patterns of all samples are of right-oblique type, similar to patterns of the post-Archean shale and the upper crust. From the Simonen and Nielv diagram, the authors infer that the original rocks of Shenshan Formation were mainly composed of complex mineral sandstones and feldspathic sandstone, the original rocks of Kuli Formation consisted mainly of quartzite sandstone and feldspathic sandstone, and the original rocks of Shangshi Formation comprised mainly feldspathic sandstone, with a little siliceous marl and shale sandstone. Combined with residual structural features analysis, it is inferred that these metamorphic clastic sedimentary rocks formed in a shallow shore - shelf sedimentary environment. Th/Sc ratios of all samples vary in a small range (0.5-1.1) , while Zr/Sc ratios vary quite considerably (8-24), revealing the complex composition of the source region of the metamorphic rocks and the probable existence of several sedimentary cycles. In Th-Sc-Zr/10 and La-Th-Sc diagram, most of the data fall into the continental island arc area, indicating that this set of rocks might have been deposited in the basins near the continental island arc. Hf-La/Th diagrams indicate that the provenance of the original rock mostly came from ancient strata of uplift and erosion, and acidic arc source region only possessed a small proportion. It is thus obvious that the magmatic activity during its deposition was not obvious, but the source region was accompanied by tectonic uplift. Combined with geochemical characteristics, it is held that the protoliths of basement metamorphic rocks in the Xiangshan uranium orefield were formed in the residual basin of an extension environment, resulting from the post-collision between Cathaysia and Yangzi Blocks.

Abstract:Abstract: Based on fission track analysis of seven samples from Garze area on the eastern margin of the Tibetan Plateau, the authors obtained the apparent ages of the analyzed samples. Using the simulated annealing method, the authors made thermal history simulation for all samples, and obtained the thermal evolution history of these samples. According to the results obtained, the Garze area has experienced similar tectonic evolutions since Palaeogene, and the tectonic uplift occurred in 46-30 Ma and since 9 Ma of Neogene, with the uplift rate and average uplift amount being 1261 m/Ma, 2634 m and 388 m/Ma, 1043 m respectively. The tectonic uplifts in the Garze area are characterized by imbalance as well as stage and regional differences; in addition, there also exist deviations in cooling rate, uplift rate and uplift amplitude.

Abstract:Abstract: A considerable part of energy released during an earthquake is used to create fractures within the surrounding rocks. The real-time drilling mud gas from WFSD-1 shows that the fractures generated during the Wenchuan Earthquake coincide with large fluid peaks, and hence they are favorable passages for underground fluid migrations. The drilling mud gas distributes asymmetrically around the principal slip zone (PSZ), with the major anomaly zone emerging 120 m below the PSZ. Gas concentrations are much higher and vary more intensively than the upper 120 m. Additionally, the geophysical logs also prove that this zone is highly fractured and associated with serious water inrush, suggesting that the 2008 Wenchuan earthquake caused more damage to the footwall than to the hanging wall. The difference in rock strength between the volcanic hanging wall of Pengguan complex and the sedimentary footwall of Xujiahe Formation and the asymmetric stress during the rupture propagation might have contributed to the damage process.

Abstract:Abstract: Field structural analysis and microstructural analysis show that Wulonggou area has experienced a long-term structural evolution, characterized tectonically by multi-level and multi-storeyed products. Its can be broadly divided into the ductile deformation that occurred in early Triassic (240 Ma ±) and its previous period, late Indosinian - early Yanshanian (235-197 Ma) brittle-ductile deformation; brittle deformation that occurred after late Yanshanian period, especially in the early - middle Himalayan period (51-21 Ma). Late Triassic-Early Yanshanian brittle-ductile deformation was accompanied by orogenic uplift, and its performance was exhibited by the folding and faulting of the pre-existing metamorphic core on the northeast wing of the tectonites, which laid the foundation of the NWW-trending main tectonic line in the Wulonggou area, i.e., a number of formal NWW-trending ductile shear zones exhibit parallel distribution, with the tectonic activities developed in order of left-handed positive sliding- left-handed thrusting →right-handed positive sliding.

Abstract:Abstract：Massive Paleozoic-Mesozoic oil-seepages occur in the east Guizhou uplift. In this paper, crude oil samples were analyzed by GC, GC-MS and IRMS, with a discussion on their organic geochemistry and the oil-source correlation. The results show that all of the crude oils are maturate and influenced by multi-uplift tectonic activities. The crude oils from Lower Triassic Daye Formation originated from oil shale in this formation and are different from Paleozoic oil-seepages in biomarkers, family composition and free carbon isotopic composition. The crude oils from Middle Permian Maokou Formation is genetically related to Lower Permian Qixia Formation, the crude oils from Lower Ordovician Honghuayuan Formation originated from shale section of Middle Silurian Wengxiangqun Formation and Lower Cambrian Niutitang Formation, and the shale member of Middle Silurian Wengxiangqun Formation is the product of late hydrocarbon generation, suggesting the probable existence of a set of special oil-bearing compositions. These data are of positive significance for petroleum prospecting in this area.

Abstract:Abstract: Gas reservoirs in the Penglaizhen Formation within Shifang area of Western Sichuan Depression are shallow sub-tight sandstone secondary ones, whose formation mechanism differs from that of tight sandstone gas reservoirs in the underlying Xujiahe Formation. Lithologic gas reservoirs occur mainly in the study area. Gas is concentrated in the middle and upper Penglaizhen Formation with high dry coefficients. Gas is mainly from coal-measure source rock in the underlying Xujiahe Formation, with a bit originating from the original reservoirs suffering from adjustment and transformation. Anyhow, it is dominated by coal-type gas. Fluid inclusion analysis shows that there are three stages of thermal fluid flow in the Penglaizhen Formation, with the first two stages being respectively liquid hydrocarbons and gas liquid mixture of hydrocarbons charge without large-sized reservoirs and the third being large-scale natural gas filling whose corresponding accumulation time was from late Cretaceous to early Paleogene (78-34 Ma). On such a basis and in combination with the tectonic evolution, the stages of hydrocarbon generation and expulsion, reservoirs densification and source-reservoir-cap assemblages, the authors determined the formation and accumulation characteristics of gas reservoirs in Penglaizhen Formation. The lower part reservoir of Penglaizhen achieved densification during the Late Cretaceous. During the Himalayan Movement, Xujiahe gas reservoir was adjusted and renovated, and the earlier-formed deep faults were extended. A lot of deep gas source migrated upward to the upper part of Penglaizhen along faults, thus forming the shallow secondary gas reservoirs.

Abstract:Abstract: Located in the northern subbelt of the western Yarlung Zangbo ophiolite zone, Dajiweng ophiolite is mainly composed of peridotite, basalt and silicious rocks. The peridotite is dominated by harzburgite with minor dunite. Dunite occurs as patches in the peridotites. Podiform chromitite can be found in the harzburgite with dunitic envelope. According to the texture and mineralogy of the chromitite, Dajiweng podiform chromitite can be divided into three types, namely massive chromitite, disseminated chromitite and nodular chromitite. This paper mainly reports the research on the harzburgite and podiform chromitite and makes a discussion on the petrogenesis of the peridotite, the origin of the chromitite and chromitite prospect in the Yarlung Zangbo suture zone combined with the major and platinum group elements. Dajiweng harzburgite has a depleted whole rock composition with higher MgO content and lower Al2O3, CaO content than the primitive mantle, indicating that Dajiweng peridotite has experienced a high degree of partial melting. Dajiweng harzburgite has higher PGEs content (23.68×10?9-31.02×10?9) than primitive mantle. The Cu and Pd content of Dajiweng harzburgite strongly deviates from the modeled partial melting curves, which is a symbol of melt-rock reaction. During the process of melt-rock reaction, sulfides were enriched with PPGEs and these materials were added to the Dajiweng harzburgite. In the primitive mantle-normalized PGE patterns of podiform chromitite, Dajiweng chromitite shows obvious enrichment of IPGE and Rh, and depletion of Pt and Pd. Podiform chromitites of different types have consistent primitive mantle-normalized PGE patterns. Ultramafic rock in the Yarlung Zangbo ophiolite belt shows remarkable similarities in such aspects as rock assemblage, rock geochemistry, formation age and petrogenesis, suggesting that the Yarlung-Zangbo ophiolite is a promising prospecting area for chromitite.

Abstract:Abstract: The Changxing potash feldspar migmatitic granite is related to the mineralization in the Hebaoshan gold deposit. The mineralization in the Hebaoshan gold deposit shows multi-period and multi-stage characteristics, and the intrusion activities of Changxing potash feldspar migmatitic granite in the late Caledonian promoted the?early?period migration and enrichment of the ore-forming elements in the gold deposit and the tectonic-magmatic activity of the late Indosinian to early Yanshanian superimposed mineralization. The authors made a detailed chronological study of the main intrusive rocks formed in the Caledonian period. In-situ zircon U-Pb dating was performed with LA?ICP?MS, and reliable n(206Pb)/n(238U) age data of zircons were obtained. The results yielded concordant age of (437.1±1.3) Ma for potash feldspar migmatitic granite, (436.6±1.1) Ma for biotite quartz diorite and (427.1±1.4) Ma for biotite granite diorite vein. The age data constrain the upper limitation of the metallogenic period, thus having great geological implications for further mineralization research.

Abstract:Abstract: This paper presents the magma zircon LA-ICP-MS U-Pb isotopic dating results of the Xingfushan granites. The weighted mean age (157±2 Ma) was obtained from 15 test points on the oscillatory zones. Inferred from the same test positions and the coincident dating result with Re-Os isotopic age of molybdenite from the Xingjiashan molybdenum-tungsten deposit, the granites here crystallized in this period. The other two captured zircons from the same assay at the separate age of (2798±13) Ma and (2250±18) Ma imply possible existence of Neoarchean-Paleoproterozoic intrusive basement, whereas No. 7 point at the age of (230±6) Ma implies possible Triassic magmatic activity. The consistent features of the tectono-magmatic activities in eastern China since Mesozoic (190?110 Ma) produced the corresponding varied metallogenesis here. The common granites of Linglong and Xingfushan units in Jiaodong Peninsular share almost the same geochemical features and ages, suggesting that this area might have hosted large-scale molybdenum polymetallic metallogenesis. Under heavy regional denudation by late tectonic uplifting, the left Xingjiashan molybdenum-tungsten deposit typically shows less denudation in Qixia-Fushan area since Mesozoic and better metallogenic condition, so more importance should be attached to the prospecting for hypabyssal deposits (porphyry-skarn, Carlin and organic hypabyssal deposits) here.

Abstract:Abstract: The Lakange porphyry Cu-Mo deposit in the Gangdise metallogenic belt of central and southern East Lhasa block within the Tethys tectonic domain is one of the key deposits in the Tibet Plateau geological survey project evaluation in recent years. Re-Os isotopic dating technique was applied for determination of mineralization events, and eight molybdenite samples were analyzed for Re-Os isotopic compositions, with the model ages obtained ranging from (13.20±0.20) Ma to (13.64±0.21) Ma, and the isochron age being（13.12±0.44）Ma which represents the metallogenic age of the Lakange porphyry Cu-Mo deposit, indicating Miocene. The Re content of the molybdenite is 343.6×10-6-835.7×10-6, with an average of 557.8×10-6, suggesting that the metallogenic material originated from a source with mantle components. The Lakange porphyry Cu-Mo deposit was formed in a stretching background of India-Asia continental collision orogenic collision, the age (17-12 Ma) is identical with ages of numerous porphyry-skarn mineralization systems in the eastern of Gangdise metallogenic belt, and is 2-3 Ma younger than ages of the porphyry-skarn copper polymetallic deposits in the same ore concentration area, such as Jiama, Qulong and Bangpu, with the formation controlled by the same metallogenic geodynamics setting.

Abstract:Abstract: Porphyry-skarn deposits in Jiurui area constitute an important part of the middle-lower Yangtze River Cu-Au-Mo (Fe) polymetallic ore belt. Since the implementation of the prospecting breakthrough strategy, the Baoshan deposit has been the first medium-size porphyry-skarn copper polymetallic deposit discovered at the core of Jieshou-Daqiao anticline in Jiurui area. In this paper, molybdenite Re-Os dating was used to study the mineralization time of the Baoshan deposit and, as a result, six molybdenite Re-Os model ages of 147.2±3.6 Ma to 150.5±2.7 Ma and weighted average age of 148±1 Ma (MSWD=1.03) were obtained. These six molybdenite Re-Os model ages yielded an isochron age of 148.6±2.6 Ma (MSWD=1.9), which represents the ore-forming age of the Banshan deposit. The ore-forming age of the Baoshan deposit is similar to ages of other porphyry-skarn type copper polymetallic deposits in Jiurui area (e.g., Wushan, Chengmenshan, Fengshandong of Hubei, Jilongshan, Songjiachong, Dengjiashan and Tongjiangling), as well as in Tongling and southeastern Hubei areas within the middle-lower Yangtze River region. All of them are products of granitic magma activities related to the crust-mantle syntexis resulting from the upwelling asthenosphere and the underplating basaltic magma in the Yanshanian period.

Abstract:Abstract: The Jiangjiaya Pb-Zn deposit, located on the southeastern margin of the Yangtze craton and along the axis of the Hongyanxi anticline, is an important Pb-Zn deposit in the western Hunan-western Hubei metallogenic belt. The orebody exhibits stratabound and veined forms and is controlled by strata and faults, and the deposit occurs in the Ordovician (Early Paleozoic) Nanjingguan Formation. The ultra-low procedural blanks and Rb-Sr dating of quartz separates yielded an isochron age of (372±9.8) Ma, with n(87Sr)/ n(86Sr) equal to (0.709409±0.000058) for the deposit, which represents the main stage ore-forming age of the deposit. Geological setting indicates that the formation of the deposit was probably related to the late Devonian mass movement of basin fluids resulting from extensional and fault depression in South China. Initial Sr isotope ratios show that the ore materials of the deposit were derived from the host rocks, and the influence of continental crust was obvious in the ore-forming process.

Abstract:Abstract: Located at the southern center of the Sichuan-Yunnan-Guizhou lead-zinc polymentallic mineralization domain on the southwestern margin of the Yangtze block, the Zhaotong lead-zinc deposit in Yunnan Province is a typical representative in northeastern Yunnan or even in Sichuan-Yunnan-Guizhou area. The deposit is characterized by vertical zoning from coarsegrained pyrite, dark-color sphalerite + ferro-dolomite + quartz, rosy sphalerite + galena + pyrite to fine-grained pyrite from bottom to top of the orebody. These typical features are different from known lead-zinc deposit types discovered both in China and abroad, such as Mississipp Valley Type (MVT), Volcanic Hosted Massive Sulfide Type (VHMS), and Hydrothermal Sedimentation Type (SEDEX). The controlling of pH, logfo2, loga over the main metal sulfides and their assembly as well as mineral zoning will contribute to solving the formation mechanism of lead-zinc association and differentiation and the extreme enrichment of elements. Metallic minerals in the mineral zoning are the main study object, and pH-logfo2, pH-loga phase diagrams of the Zhaotong lead-zinc deposit at ore-forming temperatures (373 K, 423 K, 473 K, 523 K) were drawn. On the basis of these phase diagrams, the characteristics of the mineral zoning in the Zhaotong lead-zinc deposit that are different from features of known lead-zinc deposit types discovered in the world could be explained successfully. It is believed that the association of temperature, oxygen fugacity, component concentration and pH caused the lead-zinc association and differentiation and controlled the precipitation of main metal mineral assemblages and the zonation of mineral assemblages. When the temperature drops, the logfo2 value rises, pH goes up, and the sulfide will precipitate more easily.

Abstract:Abstract: The steeply-dipping wolframite-quartz veins occur on both sides of the top contact zone of early Yanshanian granite, extending about >1000 m in the granite and about >500 m in sediments within the Yaogangxian tungsten deposit of Hunan Province. The sedimentary rocks overlying the granite consist of Precambrian metamorphic sandstone, Devonian sandstones and Triassic carbonaceous siltstone. Arsenopyrite topaz rocks （layers）occur along the sandstone overlying the Triassic-Devonian unconformity, and the tungsten-bearing quartz vein under the rocks （layers） is about 0.3 m in width. The studies of geology and geochemistry show that arsenopyrite-topaz rock mainly originally consists of quartz sandstone, with strong silicification, accompanied by arsenopyrite, topaz, muscovite and some other minerals, suggesting an altered rock. The rocks rich in Si, F, B and ore-forming elements such as W, Bi and Mo are similar to features of quartz veins. The fluid of alteration is the same as ore-forming fluid of quartz vein. The vertical zoning of the Yaogangxian tungsten deposit is different from the "five floor model" of wolframite-quartz veins. There are not veinlet and linear vein zones at the top of the model, but the arsenopyrite-topaz rock layer directly and gently dips over the steeply dipping quartz wide vein（0.3 m）. A new metallogenic model for the tungsten bearing quartz vein deposit is suggested in this paper, i.e., “layer in the upper part and vein in the lower part”. This model is of significance for the exploration of vein-type tungsten deposits, i.e., under the strongly silicified bedding alteration rocks with arsenopyrite, topaz and muscovite, there might occur steeply dipping wolframite-quartz veins.

Abstract:Abstract: Carbonate rocks of Meso-Proterozoic and Neo-Proterozoic period are widely distributed along Yanshan fold belt in southern Zhangjiakou and are composed mainly of dolomite. Some polymetallic mineral deposits (ore spots) , such as LaingJiagou, Yingdonggou and Changzhuangzi, are distributed in strata. With the Liangjiagou deposit as a study object, the authors used statistical method and local singularity means to analyze the data of stream sediments (1∶200000) so as to delineate geochemical anomalies. The results show that the areas of geochemical anomalies include three major faults, where there is great potential in search for polymetallic orebodies according to the epigenetic genesis of the ore deposits. The authors adopted densed sampling in important potential areas and delineated three geochemical anomalies. A comprehensive analysis shows that No. 3 anomaly is relatively weak and is consistent with the orebody. No. 1 and No. 2 anomalies not only have high intensity but also possess fairly large areas. The primary halos of bedrock profile survey show that the content of Pb, Zn and Ag in dolomite is significantly higher that in the center of the anomaly area, and this provides further evidence for the prospecting potential of the anomaly area.

Abstract:Abstract: The central Guizhou-southern Chongqing area had experienced peneplanation at the beginning of Ziyun Movement before the end of the Devonian. In the deposition process of the Carboniferous bauxite-bearing rock series, the lower bauxite-bearing rock series (iron-clay rock) was mostly offshore lake facies, and the upper bauxite-bearing rock series (aluminous rock) was mostly offshore plain facies. In this environment, the influence and reformation of ingression and strong storm surge were frequent. Thus, there exsited a few marine plant fossils (brachiopoda) and marine microfossils (acritarch and conodont) in the bauxite-bearing rock series, which mostly deposited in a continental environment. And there were less marine carbonate lens in the lower (iron-clay rock segment) and the upper (aluminiferous rock segment) bauxite-bearing rock series, suggesting?obvious characteristics of?marine?deposition. All these phenomena indicate that the formation environment of the bauxite-bearing rock series in central Guizhou-southern Chongqing area was very?diverse and complex. It was affected not only by continental sedimentary environment but also by other factors.

Abstract:Abstract：Based on the study of topsoil of the central and southern plain in Hebei，the authors analyzed the morphology of seven heavy metals in topsoil，evaluated the biological availability of the heavy metal elements，and studied the factors which might affect the biological availability of heavy metal elements by means of correlation analysis. The results show that the content of element-available Cd is 36.83% in topsoil, the highest among all metal elements that have greater potential ecological harmfulness. The content of element-available and carbonate Pb is respectively 13.37% and 12.38%, suggesting smaller harmfulness because of neutral and alkaline soil in the study area. The total values of Cu, Hg, Cr, As, Zn that maintain stable state account for more than 90%, implying smaller harmfulness. The activity coefficients and migration coefficients of heavy metal elements in topsoil in the study area are respectively arranged in order of Cd > Pb > Hg > Cu > Zn> As > Cr and Cd > Hg > As > Cu > Pb > Zn > Cr, with the average of the Cd achieving respectively 0.330 and 0.160, implying a strong biological activity, instability and migration capability. Other soil heavy metals show smaller activity coefficients (except Pb) and migration coefficients，indicating that their biological activities are weak and it is difficult for them to transfer from soil to plants. The relationships between biological effectiveness and influential factors of various heavy metals are not the same; nevertheless, the dominant factor is the total amount of soil heavy metal elements, followed by pH, TOC, CEC, clay content and other factors. There exist complicated relations between them.

Abstract:Abstract: The OSL dating results show that the deposition of the Xiashu Loess (Xiashu Formation) in the Hefei Basin began in the late period of the Middle Pleistocene. In this study, the major geochemical elements and grain sizes of the Xiashu Loess in Hefei were compared with those of Northwest (NW) loess, Xiashu Loess of Zhenjiang, Wushan Loess and Xuancheng Loess. The provenance of the Xiashu Loess in Hefei was discussed. Studies of geochemical characteristics, grain size content and deposition rate show that the provenance of the Hefei Xiashu Loess differs from that of the nearby Zhenjiang loess and the Northwest China Loess which were derived from the northern deserts. The lithofacies palaeogeography and the paleoclimate indicate that the abundant fine-grained sediments of the alluvial-lacustrine deposits in the Huaihe floodplain seem to be the major source materials of the Hefei Xiashu Loess.

Abstract:Abstract: Nanzhang/Yuanan Fauna, which is yielded in the laminated limestone and micrite at the top of 3rd member of Jianglingjiang Formation, is characterized by marine reptiles, together with some Homoneneae and mollusk. The age of Nanzhang/Yuanan Fauna is late Olenekian Spathian of Early Triassic. The assemblage of marine reptiles in this fauna comprises Hupehsuchia, Ichthyosauria (Chaohusaurus), and Eosauropterygia (Hanosaurus, Keichousaurus, and Nothosauridae). Compared with other marine reptiles, Hupehsuchia has most abundance and diversity in this fauna. The high specialized skeleton of Hupehsuchia indicates that this animal should exist at the bottom of marine reptiles’ food chain. A lot of marine reptiles lived in Nanzhang/Yuanan Fauna, which indicates that marine ecosystem should begin recovery in late Spathian after late Permian mass extinction.

Abstract:Abstract: Basing on paleomagnetic methods, the authors reconstructed the location of Permian paleoplate, And combination with regional geological information, compiled the Permian global paleoplate map, global lithofacies paleogeography map and distribution map of hydrocarbon source rocks in Permian. Pangea and Panthalassa around were the main continental pattern. Rift systems were well developed, such as the North Sea-North Atlantic rift system in Laurasia and the rift system in African. The continuous development of the rift systems eventually led to the breakup of Pangaea. Meanwhile, Due to the continuous development of glaciation in Permian and the widespread drought environment, global sea levels in the late Permian reached the lowest in Phanerozoic. Shallow seas were wildly spread around Neo-Tethys and Paleo-Tethys. These paleogeographic environments caused the deposition of shallow marine carbonate and clastic sediments in the whole Neo-Tethys periphery and Laurasia. Lacustrine clastic sediments were deposited internally in Gondwana. Source rocks in Permian were not widely developed, the main layer system was Lower Permian shale, which was mainly concentrated in the northern margin of Laurasia, Tethys periphery and interior of Gondwana as well as eastern margin of Australia, dominated by transitional facies depositional environment.

Abstract:Abstract: The Xar Burd Mountain and adjacent areas of Junggar Basin in Xinjiang constitute one of the major representative districts for the study of the Devonian and Lower Carboniferous strata in the Junggar-Hinggan stratigraphic region, and hence have aroused much interest among geologists. In this paper, major strata concerned are those below and above the Upper Devonian Hongguleleng Formation. The Haer Member (new name) is named to represent the basal part of the original Hongguleleng or “Hebukehe” Formation established by the Regional Geological Survey in the 1970’s, which is characterized by a large suite of conglomerate-sandstone-siltstone. A thick interval of conglomerates features the lower part of the Haer Member, which is distinctly different from the underlying original Zhulumute Formation; the contact between the two units is undulatory, probably representing a minor hiatus. The member is variously colored, including grayish green, purple-red, dark gray, etc. It yields plant fossils only, with its age assignable to the Late Devonian based on the plant Leptophloeum rhombicum, which is consistent with the original Zhulumute Formation in age, and probably also in the common nature of terrestrial facies due to the absence of marine fossils. The lower part of the Heishantou Formation is named the Namu Member (new name), which is characterized by dark gray dense sandy limestone or calcareous/siliceous siltstone with some ferruginous shelly coquinas and dark or gray, grayish green siliceous mudstone, siltstone, and (fine) sandstones. The overlying Carboniferous middle part of the Heishantou Formation is distinguished from the Namu Member by its large suite of gray-black siltstone-mudstone. The underlying Chasi Member (Hongguleleng Formation) is distinct from the Namu Member in its weathering (brown) yellow color of the rock. The Namu Member yields the ammonoids Cymaclymenia spp. and Mimimitoceras sp. and the trilobite Omegops, which suggests that the member still belongs to the Devonian. In addition, the new brachiopod Syringothyris-Spirifer fauna is present in the Namu Member, which is different from the cyrtospiriferid fauna of the underlying Chasi Member.

Abstract:Abstract: Based on core observation, casting thin sections, petrological features, sedimentary structures, paleontology marks, and mineralogical and geochemical analysis, combined with well log interpretation results of Chang 9 oil set of high resolution sequence stratigraphy and the plane distribution of sand body in Hongjingzi area, the authors have found that, in the period of Chang 9 oil set, this area developed a typical shallow water delta depositional system in which the sand body showed blanket distribution characteristics. High resolution sequence stratigraphy studies show that Chang 9 oil set can be divided into two lake transgressive-retrogressive cycles, i.e., the upper Chang 91 and the lower Chang 92. The base level cycle structure analysis revealed that Chang 9 oil set in this area can be identified as being composed of a large regional lake transgressive sequence and two secondary lake transgressive-retrogressive cycles, and can be divided into a long-term cycle sequence, two middle-term cycle sequences corresponding to the Chang 91 and Chang 92 oil set respectively, and four base-level rising and falling phases corresponding to small layers, including lake transgressive-retrogressive depositional systems tracts. In addition, the authors set up the isochronous stratigraphic framework of Chang 9 oil set, and carried out the tracking correlation and prediction of small layers sand bodies.

Abstract:Abstract: The sedimentary rocks from Kongdian Formation to the early period of the fourth member of Shahejie Formation in the western part of the south slope of Dongying Depression consist of a set of red beds mainly comprising red terrestrial clastic sediments. Based on an analysis of applicability of erosion thickness with different restoration methods and a comparative evaluation of different methods for restoring erosion thickness, the authors have found that the tectonic cross section method can be mainly used to define the erosion thickness interval and eroding range of calibration, the mudstone acoustic time and deposition rate method is suitable for the identification of the numerical interval of erosion thickness, the acoustic interval transit time method is better than other methods in the area near the uplifted block of Linnan fault and Gaoqingpingnan fault, the optimization deposition rate method is better than other methods in Pingfangwang area, and the optimized porosity method is more accurate in the red layers, especially in the lower member of Es4 formation. The results from inclusion thermometry testing method and vitrinite reflectance method can only be regarded as the single well data points for reference.

Abstract:Abstract: Global geological?mineral database involves different sources,?multiple storage formats,?lots of languages and?different scales,?and hence the quality of?data is the key to the capability of information service for the society.?During the database construction,?project?group compiles?a standard document,?establishes a quality control?mechanism,?programs a?quality check software?and?forms a?new?data quality control pattern.?This paper?focuses on the?quality?control mechanism of database?construction,?the data quality content and?the?method of quality inspection?technology.