Abstract:Abstract：The Liushuigou intermediate-basic meta-igneous complex at Guanzizhen, Tianshui, is composed mainly of metagabbro-metagabbro diorite-metadiorite, and the Baihua basic meta-igneous complex consists mainly of pyroxenite-gabbro (-diorite)-diorite-quartz diorite. They form a relatively complete comagmatic evolutionary series. The geochemical characteristics of basic to intermediate-basic igneous rocks indicate that they belong to a tholeiite suite. Their chondrite-normalized REE patterns are of nearly flat and slightly LREE-enriched type, and their primitive mantle-normalized and MORB-normalized trace element spidergrams are generally similar; the LILEs Cs, Ba, Sr, Th and U are enriched, while Rb and K and the HFSEs Nb, P, Zr, Sm, Ti and Y are depleted. All these show comagmatic evolutionary and genetic characteristics. The tectonic environment discrimination by trace elements reveals that these igneous complexes formed in an island-arc setting. The TIMS single-zircon U-Pb age for the Liushuigou intermediate-basic meta-igneous rocks in the Guanzizhen area is 507.5±3.0 Ma, representing the age of these igneous complexes, which indicates that island-arc-type magmatic rocks in the north zone of the West Qinling are Late Cambrian in age and also reveals that the timing of subduction of the paleo-ocean basin represented by the Guanzizhen ophiolite and resulting island-arc-type magmatic activity is probably Late Cambrian to Early Ordovician.

Abstract:Abstract：The Paleoproterozoic Beidahe Group-complex remains as continental shivers in the interior of the North Qilian orogen. In its early stage of development, there occurred abundant amphibolite. The protolith of the amphibolite is basalts. The Alk-∑FeO-MgO plot, REE features and Rittmann index show that the protolith belongs to the calc-alkaline suite and exceptionally shows the subalkaline character. The rock is characterized by higher Al2O3 and ΣFeO and lower Mg#, indicating that it has a higher degree of compositional evolution and that the formation of volcanic rocks is related to activation of older crust. Highly fractionated REE patterns and amphibolite on the Ti-Zr-Y plot, Ni-FeO/MgO plot and Ta/Yb-Th/Yb plot all indicate the characteristics of volcanic arcs and active continental margins. On the geochemical diagram of basalt, the overall REE features are in the main analogous to those of calc-alkaline island-arc basalt, with Sr87/Sr86＝0.71617–0.72033，Nd143/Nd144＝0.512414–0.512495 and εNd＝–2.79 to –4.37，εSr＝245.78–305.3, showing that the magma was derived from the crust or subjected to contamination with the lower crust below the continent. So it may be inferred that the protolith of the amphibolite is the product of different degrees of partial melting of the mantle in a magma arc. This suggests that subduction of a paleo-ocean basin occurred between the Paleoproterozoic North China craton and Qaidam craton.

Abstract:Abstract：The Xiangshan area as the largest volcanic-hosted uranium ore occurrence in China has received great attention. From eruption→viscous lava extrusion→intrusion, the SiO2 content, Rb/Sr and Rb/Ba of the Xiangshan volcanic-intrusive complex decreased, while the TFe (Fe2O3+FeO), CaO, MgO, P2O5 and TiO2 contents and the solidification index SI and δEu increased progressively, showing that the magmatic evolution has an antithetic relationship with the magmatic differentiation trend reflected by increasing acidity in the normal magma chamber, which is called the reverse magmatic evolution series. The incompatible element radios such as Th/U, Rb/Ba, Th/Nb, Th/Ta, Nb/Ta and La/Nb vary widely, showing no distinct synthetic or antithetic relationship with the major components such as SiO2. The REE distribution patterns also vary. These suggest that the volcanic eruption facies, viscous lava extrusion facies and intrusive facies were derived from different sources.

Abstract:Abstract：Southeastern Hunan and the Hunan-Guangdong-Jiangx border area belong to the northern part of the central segment of the Nanling Range. This region is a favorable window for studying Mesozoic tectonic setting and evolution in South China. According to isotopic chronological, geological and geochemical studies, the time ranges and tectonic settings of granites of three Mesozoic ages are determined, and on that basis, combined with the characteristics and genetic mechanism of continental basins of different Mesozoic ages and volcanic rocks, stages and characteristics of tectonic deformations and ore-forming processes, a preliminary sequence framework of the Mesozoic geological events is defined. Four major stages of Mesozoic tectonic evolution in the region may be distinguished; from early to late times they are the Early Triassic－early Middle Triassic pre-orogenic stage (I), the late Middle Triassic–early Middle Jurassic intracontinental orogenic stage (Ⅱ), the early Middle Jurassic–Late Jurassic post-orogenic stage (Ⅲ), and the Cretaceous intraplate rift stage (Ⅳ). ｏf these，stage II may be further divided into four substages (Ⅱ1–Ⅱ4). The pre-orogenic stage (Ⅰ) was a stable marine sedimentary stage. The late Middle Triassic (Ⅱ1) was an intracomtinental subduction-converge peak stage, when a great deal of mainly NNE-directed thrusts and folds formed, resulting in crustal thickening. In the terminal Middle Triassic–latest Triassic (Ⅱ2）, compression was relatively relax and a great deal of crustal-derived granitic magma formed and was emplaced (233–210 Ma). There was a syn-orogenic uplift-extensional tectonic setting in the terminal Late Triassic–Early Jurassic (Ⅱ3), when the NNE-directed rift coal-bearing basins formed and high-Na and low-K tholeiitic magma was erupted. The initial Middle Jurassic (Ⅱ4) witnessed NNE-directed sinistral convergence-strike-slip orogeny, when thrusts formed and early-formed rift basins underwent inversion to transform to piedmont thrust-contractive basins. In the early Middle Jurassic－Late Jurassic post-orogenic stage (III), voluminous post-orogenic granite was emplaced (at 174－135 Ma), accompanied by extensive mineralization. At the end of the Jurassic there occurred a transient compression event. In the Cretaceous intraplate-rift stage (Ⅳ), there occurred such tectonic associations as basin-range tectonics and metamorphic core complexes, bimodal volcanic rocks and subvolcanic rocks, acid dikes and Shangbao small intrusions with the characteristics of AA-type granite. Finally, the paper discusses the early Yanshanian tectonic environment and the formation mechanism of tectono-magmatic characteristics of different stages in the Mesozoic in South China.

Abstract:Abstract：Eastern Jiaodong, regionally located at the eastern end of the Qinling-Dabie-Sulu orogenic belt, is a Mesozoic strike-slip thrust belt. The study of ultramicroscopic structure is favorable to solving the problem of deformation mechanisms of rocks. Microstructure and ultramicrostructure of the strike-slip thrust belt in eastern Jiaodong have been studied using both microscopy and TEM. Study indicates that the dislocation substructure of quartz in the main strike-slip thrust shear zone is dominated by linear dislocation, and in addition, dislocation loops, bow-out, walls, arrays and net and subgrains are also common. A middle- to low-temperature, plastic deformation environment. can be deduced from the ultramicroscopic dislocation structures of quartz. Furthermore, the average differential paleo-stress values of the Shidao, Rongcheng and Mouping shear zones show a trend of gradual decrease, which seems to be inversely correlated with the trend of temperatures.

Abstract:Abstract：The Qinling orogenic belt is the junction between the North China plate of the Sino-Korean craton and the Yangtze cratonic plate and its basement arouses attention of many geologists. This paper reports the zircon SHRIMP U-Pb age data for the Loufanggou metamorphic crystalline rock sheet amphibolite-leptite and biotite-bearing monzonitic quartz schist in the Xianghe area, Shangnan, Shaanxi, in the central part of the Qinling orogenic belt and discusses their geological significance. Amphibolite-leptite is meta-volcanic rocks resulting from continuous differentiation of the same magma. Zircon Pb loss is serious and the 207Pb/206Pb age is ≥2488±8 Ma. This age is consistent with the available Sm-Nd isochron age with the error limits. Biotite-bearing monzonitic quartz schist is parametamorphite with a zircon U-Pb age of 978±13 Ma. The discovery of an Archean sheet (block) in the central part of the Qinling orogenic belt suggests that the Archean crystalline basement may have existed in the lower part of the Qinling orogenic belt.

Abstract:Abstract：Granites and related dikes in the Bengbu area have been dated precisely by using the 40Ar-39Ar dating technique. The results indicate that there occurred Precambrian magmatism but also Mesozoic magmatism on the southeastern margin of the North China Ｂlock in the Bengbu area. According to the age data available, the Mesozoic magmatism in the area is divided into the early Yanshanian and late Yanshanian phases and five stages. A chronological framework of Late Mesozoic magmatism has been preliminarily established.

Abstract:Abstract:The top of the Yixian Formation in the area western Liaoning, BeipiaoYixian, the Huanghuashan breccia or rhyolite above the Jingangshan bed of the Yixian Formation. Zircon of the rhyolite sample LAICPMS U-Pb dating gives weighted mean ages of 118.9 ± 1.4119.8 ± 1.9Ma. In addition, dacite porphyry injected into the lower part of the Huanghuashan breccia is dated by us Ing the 40Ar / 39Ar method, which has a plateau age of 122.1 ± 0.3Ma and an isochrone age of 121.8 ± 1.4Ma. These age data suggest that the top of the Yixian Formation in the area formed at BeipiaoYixian 122119 Ma. The determination of the age of the top of the Yixian Formation defines not only the upper age limit (~ 122 Ma) for the Rehe top part of the Yixian Formation Faunabearing (i. E. the Jingangshan bed) but also the upper age limit (- 118.9 ± 1.4Ma119.8 ± 1.9 Ma) of volcanic rocks of the Yixian Formation. The age of the top of the Yixian Formation in the area is also a very important ending age of Cretaceous magmatism in Western Liaoning Largescale and even Northeast China.

Abstract:Abstract：The Tongguanshan copper field in Tongling, Anhui, is one of the typical skarn orefields in the middle-lower Yangtze Valley iron, copper, sulfur and gold metallogenic belt of China. The Xiaotongguanshan copper deposit located in the Tongguanshan copper field is related to the Tongguanshan quartz monzodiorite. The formation of the copper deposit progresses through the skarn stage, quartz-sulfide stage and quartz-carbonate stage. Based on the geological setting, mineralogy and tectonics of the deposit, combined with the hydrogen, oxygen, carbon, sulfur and silicon isotopic compositions and REE geochemistry of the ore-forming fluids, this paper deals mainly with the sources of water, silicon and sulfur in the ore-forming fluids and their evolution. The results show that the ore-forming fluids were dominated by magmatic water at the early stage, whereas with an increase in meteoric water entering the mineralizing system, the meteoric water might predominate at the late stage. Sulfur has two sources, i. e. strata and magmatic hydrothermal fluids, with the latter predominating. Silicon shows the features of deep-seated magma or magmatic hydrothermal fluids. Chondrite-normalized REE patterns are right-inclined, and the REE distribution patterns for skarn and ores are similar to those of the Tongguanshan quartz monzodiorite, which indicates that the hydrothermal fluids of the skarn deposit in the study area were mainly derived from dioritic melt.

Abstract:Abstract:Oreforming fluids related to the magma system can be divided Intermediateacid according to fluid mineralization into silicate melt formed in the acid magmatic slage, the mixture of silicate melt and its exsolved hydrothermal fluids during the transitional stage from silicate melt to hydrothermal fluids hydrothermal exsolved from the Intermediateacid Orefluids Melts, and migmatized fluids formed during the formation Oreforming of granites migmatitization of metamorphic rocks. The acid magma system mainly provides heat and a part of ore sulstances and the heat provided ly it drives sulsurface water to leach the country rocks and extract ore sulstarces from the country rocks, thus forming sulsurface hydrothermal ore flids.On the basi S of these studies, detailed trace element geochemical characteristics of the different fluids and their Alovementioned Oreforming controls on mineralication are discussed.

Abstract:Abstract：Owing to lack of formation temperature data of mylonites, such problems as the formation depth, metamorphic evolution, deformation mechanism, exhumation history of mylonites, relation with host rocks and explanation of isotopic age data are difficult to interpret correctly and reasonably. The muscovite-chlorite geothermometer, muscovite-biotite geothermometer and chlorite compositional geothermometer that are suited to the low-temperature conditions have only been used in the interpretation of regional metamorphism of sedimentary rocks and have never been used for mylonites of ductile shear zones. In this paper an attempt is first made to apply the above-mentioned three geothermometers in mylonite by using syn-tectonic neogenic muscovite, biotite and chlorite of mylonites in a ductile shear zone in the southern segment (Anhui segment) of the Tanlu fault zone. According to the neogenic mineral assemblages and deformation behaviors of feldspars, the deformation temperatures of the Tanlu fault zone range between 350℃and 450℃. The temperatures obtained using the muscovite-biotite geothermometer and chlorite compositional geothermometer range between 672℃ and 1116 ℃ and between 470℃and 520 ℃ respectively, being higher than the deformation temperatures of mylonites in the ductile shear zone, which suggests that the two geothermometers are not applicable to calculation of the formation temperatures of low-temperature mylonite. The temperatures obtained using the muscovite-chlorite geothermometer coincide with the deformation temperatures of mylonites in the Tanlu ductile shear zone, which suggests that among the above-mentioned three geothermometeres, only the muscovite-chlorite geothermometer is applicable to the measurements of the formation temperatures of low-temperature mylonites.

Abstract:Abstract：The Mujiazhuang copper deposit is located in the Devonian strata in the Zhashui-Shanyang area of the South Qinling orogenic belt. Orebodies occur in a fault near the axial region in the southern limb of the Jinjinghe-Ｈujiamiao inverted secondary anticline in the southern limb of the Hongyansi-Heishan composite syncline. Host rocks are dolomitic rocks in the middle and upper parts of the Devonian Qingshiya Formation. Their spatial distribution is obviously controlled by an interlayer fracture-fissure zone near the axial region in the steeply dipping southern limb (inverted limb) of an anticline. Ores are dominantly of nodular and stockwork types and the feature of epigenetic mineralization is very pronounced. This paper discusses the sources of ore-forming materials and ore genesis of copper deposits in the Devonian in the Qinling Mountains through a study of lead isotope geochemistry. The lead isotope study shows that ores of the Mujiazhuang copper deposit and the host rocks contain very high radiogenic lead. On the basis of an integrated comparison of ore lead, host rock lead and whole-rock lead in Cambrian carbonaceous-siliceous rocks, it is found that their compositional features are similar, suggesting that lead in the Mujiazhuang copper deposit was derived from the Cambrian.

Abstract:Abstract：Major advances have been made in mineral exploration in the Liqingdi lead-zinc-silver deposit, central Inner Mongolia in recent years. This deposit is an epithermal deposit related to Jurassic continental volcanism. The mineralization is controlled by a volcanic edifice formed by circular and radial fractures centering on the Danaobaoshan volcano. Previously it was considered that the ore-controllｉｎｇ fractures strike NE. Although large amount of exploration work had been done, only reserves of small silver deposits were obtained. Study shows that the NE-trending (basement) fractures control the ore zoneｓ, while the NW-trending fractures control orebodies. The major lead-zinc-silver orebodies occur in the NW-trending fractures and oreshoots occur near the intersection site of the NW- and NE-trending fractures. This new idea of the ore-controlling fractures leads to a new breakthrough in mineral exploration in the Liqingdi deposit and discovery of lead-zinc-silver oreshoots. At present several NW-trending ore-bearing fractures have been found successively in the ore district, indicating that the entire Liqingdi ore district has the potential of becoming a superlarge lead-zinc-silver deposit.

Abstract:Abstract：The Donghe sandstone is a marine petroleum-bearing reservoir that was first found in China. An integrated study of the geological and geophysical data of the Tarim basin show that the Donghe sandstone in Tabei and Taｚｈong has high compositional and textural maturities, typical grain-size parameters of the marine environment and trace element association and distinct littoral-neritic sedimentary structures. However, there are differences in details of sedimentary characteristics and sedimentary environment in the Donghe sandstone. The Donghe sandstone in the Tabei area was deposited in the littoral and barrier island－lagoonal environment, while the sandstone in the Tazhong area in the estuary－littoral environment. Finally, this paper elucidates the vertical sequence ｏｆ the sedimentary characteristics and distribution of sedimentary facies of the Donghe sandstone ｓｅｃｔｉｏｎ in the Tabei and Tazhong areas.

Abstract:Abstract：The Paleogene sedimentary characteristics from the 1st Member of the Kongdian Formation to the 4th Member of the Shahejie Formation in the southern Jiyang depression have been studied by core observation, thin section identification，grain size analysis, fossil identification and log interpretation. Results indicate the following：the Jiyang depression was in the initial stage of lake downfaulting from the 1st Member of the Kongdian Formation to the early stage of the 4th Member of the Shahejie Formation and the sedimentation was significantly controlled by inflow of ephemeral flood; a flooded lacustrine sedimentary system formed in the Dongying and Huimin subbasins. The main lithologic characteristic is that the rock types are dominated by light-colored clastic rocks reflecting the oxidation environment with a low maturity. The grain size distribution and sedimentary structure show that the rocks have the sedimentary characters of both gravity currents and tractional currents. Plant fragments are lacking and bioturbation structures are abundant and cyclic. Sandbodies are distributed in a ring shape. The sedimentary system may be divided into the side-edge distal and near-shore distal facies sequences and five microfacies, namely, flood channel terminus, mud flat, sand flat, mixed mud/sand flat and flooded lake tempestite.

Abstract:Abstract：According to a wealth of geological and geochemical data，this paper focuses on the genesis and characteristics of migration and accumulation of CO2 and thｅｉｒ key controlling factors in eastern China and its sea areas and on that basis a preliminary evaluation of the favorable CO2 distribution areas ｉｓ ｍａｄｅ.The study shows that in various continental downfaulted basins in eastern China，the China East Sea basin of the southeast sea region and the continental shelf—Qiongdongnan basin and Zhujiangkou basin—of the northern South China Sea，CO2 in CO2 reservoirs and CO2-rich oil/gas reservoirs is of typical volcanic mantle-derived type and that its migration and concentration is mainly controlled by mantle-derived volcanism and gas-conducting distribution of deep basement faults connected with the gas source at depth. CO2 is mainly sourced from substantial amount of CO2 associated with mantle-derived volcanism at the deep level of the crust. CO2 in the CO2 reservoirs and CO2-rich oil/gas reservoirs in the Yinggehai basin on the continental shelf of the northern South China Sea is of crust origin and crust-mantle mixing origin and mainly controlled by local，layer-by-layer and zone-by-zone，multiple intrusion of late hydrothermal fluids in mud diapir areas and physico-chemical processes of very thick Pliocene-Miocene marine calcareous sandstone and mudstone. Therefore according to the characteristics of migration and accumulation of different genetic types of CO2，we can trace the CO2 source，analyze and predict the migration，accumulation and distribution of gas and especially CO2 so as to provide a basis for make the plan and decision of gas exploration and reduce the risk of exploration.

Abstract:Abstract：Under the guidance of the theory and techniques of high-resolution sequence stratigraphy, through a comprehensive analysis of the outcrops, rock cores, well logs and seismic data, 3 sequence boundaries of different genetic types and growth scaleｓ and 3 orders of lacustrine flooding surfaces are recognized in the Upper Jurassic Penglaizhen Formation in ｔｈｅ Baimamiao gas field, and in addition, 2 long-term base-level cycles, 6 middle-term base-level cycles and 38-40 short-term base-level cycles are distinguished and their characteristics are discussed in detail. The thin-bedded limestone and calcareous shale close to the top of the middle-term base-level cycle can be regarded as one of the important indicator for recognizing the middle-term base-level cycle. On the basis of the above, using the method of cycle isochronostratigraphic correlation, different orders of base-level cycles are correlated and 3 isochronostratigraphic stratigraphic frameworks with different time-scales are established. The high-resolution sequence stratigraphic analysis has great significance for further exploration and development of the gas accumulations in the Penglaizhen Formation of the Baimamiao gas field.

Abstract:Abstract：The physical properties of Paleogene sandstones reservoirs in the Huimin subbasin are mainly controlled by compaction, carbonate cementation, dissolution and depositional environment. The controlling factors of physical properties of reservoirs are analyzed based on the data from analyses of mold thin sections, cathode luminescence thin sections, scanning electron microscopy, physical properties and carbonate contents of rocks. Preliminary quantitative evaluation of the degrees of influences of these factors has been carried out. It is suggested that：① the porosity decreases by 8％–9% per 1000 m of descent due to compaction at the early burial stage or the stage of low degrees of carbonate cementation; ② the influence of carbonate cementation on the physical properties of reservoirs is related to the diagenetic evolution stages：the higher the degree of diagenetic evolution, the greater the influence of the cements on physical properties will be; and ③ dissolution plays an important role in improving the properties of the reservoirs and the secondary porosity produced by dissolution is up to 20%. However, the dissolution is mainly controlled by the regional tectonic setting and the position of the hydrocarbon-producing subbasin and the dissolution is relatively stronger in the central uplift zone ａｎｄ the south slope zone near the hydrocarbon-producing center (Linnan subbasin)where faults are better developed. The sandstones that are coarser in grain size and well-sorted, with low matrix contents have been subjected to stronger dissolution. The influence of the depositional environment on physical properties of reservoirs is manifested by the development degree of primary porosity and its controls on such diagenesis as dissolution and cementation.

Abstract:Abstract：The Shulu subbasin lying in the southwestern part of the Jizhong depression is a typical single-downfaulted subbasin in an extensional system. Its structure is simple with a NE extensional fault system and a NW-trending transverse accommodation zone. Based on the evolutionary history and drilling well data of the subbasin, this paper discusses the mechanism and time of formation of this transverse accommodation zone and proposes that the first-order accommodation zone formed in a stage of strong extension of the subbasin, while the second-order accommodation zone formed in a stage of weak extension of the subbasin. The formation of the first-order transverse accommodation zone is controlled by inhomogeneous extension of the boundary fault and basement uplift, the deference in lithologic association is the trigger mechanism of the second-order transverse accommodation zone, and the alternating development of en-echelon faults that control the subbasin is the dynamic mechanism of formation of the second-order transverse accommodation zone.

Abstract:Abstract：The geomorphologic features in the prairie of the Erenhot－Dong Ujimqin Qi area，east-central Inner Mongolia，are mostly represented by gentle hills and mounds . Because of the mixing occurrence of stream sediments，eolian sediments and weathering residues，the results of geochemical surveys are directly affected by different sample media . Comparison samples of different grain sizes from the Ataiwula property in东Ujimqin Qi and Moruogeqin in Abag Qi shows of micro grains of metallic minerals are mixed inhomogeneously in debris carriers . Compared with fine - grained samples（－80 mesh），the rock debris明确- 4 to + 20 mesh has higher geochemical contrast values，and thus their extracted anomalies are also more accurate . A thematic is mapconstructed using the IDW（Interpolation Distend Weight）method with the MapInfo program购买shows very clear spatial relationships among various elements and directly indicates favorable sites在mineral finding，which may well guide the screening of ore targets . The authorsfound several Cu - Au and Ag-Pb-Zn-Cu anomaly zones in the study area and preliminarily conformed there are zonal mineralized orebodies and good ore prospects in the area . Through practice，it is demonstrated that geochemical debris sampling and survey play an important role in the rapid localization of the areal extent在mineral reconnaissance in shallow - covered areas .

Abstract:Abstract：Construction of a biostratigraphic database is a long-term basic disciplinary project of far-reaching significance. The construction work includes standardizing the database construction flow process strictly, establishing the biostratigraphic database data-relationship and framework, developing operating system softwares, setting several inquiry functions, giving prominence to practical applicability and sharing achievements. The stratobiomarks database of China (Web edition) has been constructed recently based on collection, collation and study of biostratigraphic data. The computer technique is used to systematize, standardize and digitize the data, improve the Chronostratigraphic Table of China, unify the standards of stratigraphic division and correlation and solve some scientific problems. The construction of the biostratigraphic database involves all geologic ages and countrywide biostratigraphic databases, and it can strengthen the techno-support function of the basic discipline and promote the development of biostratigraphy.

Abstract:Abstract：Based on the application of GIS (Geographic Information System) and in small-scale regional geological map production, combined with the production of the Geological Map Series of Central Asia and Adjacent Areas, the paper expounds the methods of digital geological map production based on the GIS softwares such as Arcinfo and Mapgis and introduces the compilation of geographical and geological spatial data, including map-making generalization, attribute database production and code design of various elements, as well as supplements of new materials. According to different data sources, different technical lines and map production methods are lain down. The data from the data sources of different countries are converted into the unifying data format and projection coordinates system by data conversion, projection conversion and error correction. A concrete analysis has been made of the methods of regional geological map production based on the GIS and data sources.