• Volume 91,Issue 4,2017 Table of Contents
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    • CONTENTS

      2017, 91(4):0-0.

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    • 前言

      2017, 91(4):0-1.

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    • ORIGINAL ARTICLES

      2017, 91(4):1-1.

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    • New Evidence of Sauropod Dinosaurs from the Early Jurassic Period of Thailand

      2017, 91(4):1169-1178.

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      Abstract:The oldest dinosaur assemblages of Thailand deposit in continental sedimentary rocks of the Nam Phong Formation. Not only Isanosaurus attavipatchi was discovered but at least two more species of basal sauropods were found. A partial skeleton from Phu Hin Tan locality refers to sauropod taxon A. It is different from Isanosaurus and shares some characteristics with basal sauropods in the Early Jurassic. The sauropod taxon B was found in Non Sra Ard locality. Base on postcranial skeleton, sauropod taxon B shares some characteristics of the family Vulcanodontidae. Moreover, several fragments of the sauropods specimen are also found in Pha Khok Wang Yang and Phu Noi localities. All of the evidences above indicate that there are a highly diversity of sauropods in the Nam Phong Formation. At least three sauropod species (including Isanosaurus) were found in the Nam Phong formation. The issue about the age of the Nam Phong has been debated for a long time between the Triassic and Jurassic age. All of sauropodomorphs, in this study, are more likely the Early Jurassic period dinosaurs than the Triassic period dinosaurs. And they have deposited in the upper part of Nam Phong Formation.

    • Asplenium sanshuiense sp. nov.: the Lowest Latitude Fossil Record of the Genus

      2017, 91(4):1179-1189.

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      Abstract:Extant Asplenium is one of the most widespread fern groups and occurs in the temperate and tropical regions. However, the fossil records of this genus are poorly documented, especially in the low latitudes. Here, a new species, Asplenium sanshuiense sp. nov. is described from the early Eocene of Sanshui Basin, Guangdong Province, South China. This is the lowest modern latitude fossil record of Asplenium and the first fossil assignment of A. section Darea (Jussieu) Bak., as well as the first fossil record of Asplenium reported from South China. This new species shows that Asplenium had already spread into South China by the early Eocene and the section Darea (Jussieu) Bak. was identifiable within the genus Asplenium during that time. This new species, combined with previous fossil spore-pollen records indicates a warm and humid climate in the Sanshui Basin of the early Eocene.

    • Late Miocene Pods and Leaves of Albizzia (Leguminosae: Mimosoideae)from Yunnan, SW China and Their Phytogeographic Implications

      2017, 91(4):1190-1199.

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      Abstract:Extant Asplenium is one of the most widespread fern groups and occurs in the temperate and tropical regions. However, the fossil records of this genus are poorly documented, especially in the low latitudes. Here, a new species, Asplenium sanshuiense sp. nov. is described from the early Eocene of Sanshui Basin, Guangdong Province, South China. This is the lowest modern latitude fossil record of Asplenium and the first fossil assignment of A. section Darea (Jussieu) Bak., as well as the first fossil record of Asplenium reported from South China. This new species shows that Asplenium had already spread into South China by the early Eocene and the section Darea (Jussieu) Bak. was identifiable within the genus Asplenium during that time. This new species, combined with previous fossil spore-pollen records indicates a warm and humid climate in the Sanshui Basin of the early Eocene.

    • A New Species of Cupressinocladus from the Lower Cretaceous of Guyang Basin, Inner Mongolia, China and Cluster Analysis

      2017, 91(4):1200-1214.

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      Abstract:Cupressinocladus Seward is a fossil genus of conifers and conifer fossils with reproductive organs are very rare. In general, it is difficult to understand the natural affinities with other conifers. In this paper, a new species, Cupressinocladus guyangensis P.H. Jin et B.N. Sun sp. nov., is reported based on branches with immature female cones from the Lower Cretaceous Guyang Formation of the Guyang Basin in Inner Mongolia, northern China. The foliage shoots are decussate. Leaves are decussate, imbricate, scale-like, weakly dimorphic, and bear longitudinal glands on the abaxial view. Stomata complexes are haplocheilic, monocyclic, irregularly arranged, and spread along the leaf margin. Immature female cones are subglobose with 6–8 cone scales, and three subglobose ovules arranged in a row at the base of the cone scales. Moreover, we performed cluster analysis using a statistics and machine learning toolbox for 23 fossils and extant species based on 16 morphological characters. The result implies that the new species bears a close resemblance to the extant Cupressus funebris Endl. and might have nearest systematic affinities to it.

    • Macrobioerosion and Microbioerosion in Marine Molluscan Shells from Holocene and Modern Beaches (39°−40°S, South of Buenos Aires Province, Argentina)

      2017, 91(4):1215-1230.

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      Abstract:The marine sediments of the area of Verde Peninsula – Jabali Island (39°28′S/62°19′W–40°28′S/62°11′W) Holocene in age (3?2 ky), and modern beaches contain a significant amount of bioeroded mollusc shells. Fifteen sites were analyzed, in which 20.11% of the mollusc shells (2168 valves) presented bioerosion traces, in 54 species (30 bivalves and 24 gastropods). Fourteen ichnogenera were reported: Entobia, Maeandropolydora, Iramena, Caulostrepsis, Pennatichnus, Pinaceocladichnus, Trypanites, and Gastrochaenolites (Domichnia), Gnathichnus and Radulichnus (Pascichnia), Finichnus and Centrichnus (Fixichnia), Oichnus (Praedicnia) (macrobioerosion), y Semidendrina (microbioerosion), the latter is first reported in mollusc shells in Argentina. Eleven ichnospecies were identified Finichnus peristroma, Maeandropolydora sulcans, Gnathichnus pentax, Pinaceocladichnus onubensis, Caulostrepsis taeniola, Centrichnus eccentricus, Radulichnus inopinatus, Oichnus simplex, Oichnus paraboloides, Oichnus gradatus, and Gastrochaenolites torpedo (lithic remains). The dominant ichnogenera in the Holocene deposits are Iramena, Entobia and Oichnus. The same ichnogenera are constant with different abundance in the modern beaches, and increasing representation of Pinaceocladichnus and Pennatichnus. The dominant ichnofacies in the Holocene deposits is Trypanites, revealing a benthonic marine community composed of cheilostome bryzoans, clionaid sponges, predator gastropods, regular echinoids, polychaete annelids, bivalves, thallophytas and fungi. Generally, the area was described as a sublittoral, low-energy, stable environment with high rate of oxygenation, and sandy bottoms, with rocky bottoms at Villalonga locality.

    • Neoproterozoic-Paleozoic Tectonic Evolution of the Northeastern Tarim Block: Constraints from 40Ar/39Ar Geochronology in the Kuluketage Area, NW China

      2017, 91(4):1231-1247.

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      Abstract:Seventeen new 40Ar/39Ar analyses reported for ten Tarim Precambrian basement samples from the Kuluketage area, are applied to reconstruct the regional thermo-tectonic history together with previously published data. Eight samples were taken adjacent to the Xingdi and Xinger faults, major structures in the study area, whereas a further two were sampled at some distance from the faults. 40Ar/39Ar data from the latter record rapid cooling following a Neoproterozoic magmatic/metamorphic event and mild Paleozoic thermal disturbance. Paleozoic 40Ar/39Ar ages from the study area, as well as from the Central Tianshan and eastern Southern Tianshan suggest two strong deformational periods at ~390 Ma and ~300 Ma. During the older period, argon isotopic systems were reset/disturbed by high temperature related to arc magmatism resulting from subduction of the South Tianshan paleo-oceanic crust, possibly in combination with reactivation of Precambrian faults. The younger period is characterized by widespread late Carboniferous-early Permian intracontinental deformation, which is related to the final amalgamation of the Central Asian Orogenic Belt. Previously published apatite fission track data attest to a long history of post-collisional cooling, which is attributed to continued propagation of deformation within the Central Asian Orogenic Belt.

    • Petrogenesis of the Late Cretaceous Tholeiitic Volcanism and Oceanic Island Arc Affinity of the Chagai Arc, Western Pakistan

      2017, 91(4):1248-1263.

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      Abstract:The Late Cretaceous Chagai arc outcrops in western Pakistan, southern Afghanistan and eastern Iran. It is in the Tethyan convergence zone, formed by northward subduction of the Arabian oceanic plate beneath the Afghan block. The oldest unit of the Chagai arc is the Late Cretaceous Sinjrani Volcanic Group. This is composed of porphyritic lava flows and volcaniclastic rocks, and subordinate shale, sandstone, limestone and chert. The flows are fractionated low-K tholeiitic basalts, basaltic-andesites, and andesites. Relative enrichment in their LILE and depletion in HFSE, and negative Nb and Ta and positive K, Ba and Sr anomalies point to a subduction-related origin. Compared to MORB, the least fractionated Chagai basalts have low Na2O, Fe2O3T, CaO, Ti, Zr, Y and 87Sr/86Sr. Rather than an Andean setting, these results suggest derivation from a highly depleted mantle in an intraoceanic arc formed by Late Cretaceous convergence in the Ceno-Tethys. The segmented subduction zone formed between Gondwana and a collage of small continental blocks (Iran, Afghan, Karakoram, Lhasa and Burma) was accompanied by a chain of oceanic island arcs and suprasubduction ophiolites including Semail, Zagros, Chagai-Raskoh, Kandahar, Muslim Bagh, Waziristan and Kohistan-Ladakh, Nidar, Nagaland and Manipur. These complexes accreted to the southern margin of Eurasia in the Late Cretaceous.

    • Wedge-Shaped Pop-Up Structure in the Eslami Peninsula, Lake Urmia, Northwestern Iran

      2017, 91(4):1264-1269.

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      Abstract:Ancient subduction zones are characterized by metamorphic and orogenic belts. The Zagros Orogenic Belt comprises almost all sections of an ancient subduction zone along which Neo-Tethyan oceanic crust was subducted beneath central Iran. The Eslami Peninsula, as a part of the Zagros Orogenic Belt in Azerbaijan province, northwestern Iran, is situated between the Lake Urmia fore-arc basin and the Sahand Magmatic Arc. This region contains Eocene leucite dikes, trachyte, tephrite, phenolite, basanite and syenite. Volcanic features related to the Sahand are located in the eastern part of the Eslami Peninsula. In view of its relative age and composition, the Eslami Peninsula proposed as an outer arc of the Sahand Magmatic Arc that formed within the post-collisional setting of the central Iranian and Arabian plates. After subduction and contact of the two plates, a symmetric pop-up structure has been created by thrusting in the Zagros belt as a result of the collision processes. The injesction of dikes in the Eslami Peninsula is also a result of the continent_continent collision.

    • The Crystal Structure of Lisiguangite

      2017, 91(4):1270-1275.

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      Abstract:The crystal structure of lisiguangite, CuPtBiS3, from Yanshan mountains, Chengde Prefecture, Hebei Province, China has been determined by single crystal X-ray diffraction. It belongs to orthorhombic space group P212121 with a = 7.7372(15) ?, b = 12.844(3) ?, c = 4.9062(10) ?, V = 487.57(17) ?3, Z = 4. The final full-matric least-square refinement on F2 converged with R1 = 0.0495 and wR2 = 0.0992 for 704 observed reflections [I≥2σ(I)]. Lisiguangite is the isomorph of known CuNiSbS3 and CuNiBiS3. Pt2+ and Bi3+ have the distorted octahedral coordination enviroments composed of two metal and four S and Cu+2 has a distorted tetrahedral coordination environment with four S atoms. Each S atom is surrounded by four metals to give a tetrahedral environment. The crystal structure is a complex 3 dimensional network.

    • Oxidation and Mineralization of Mn2+ Ions Mediated by Pseudomonas putida: Insights from an Experimental Study

      2017, 91(4):1276-1285.

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      Abstract:The formation of manganese oxides in nature is commonly mediated by microorganisms. In this study, the mineralization of biogenic manganese oxidation mediated by Pseudomanas putida has been experimentally investigated by employing various characterization techniques, including SEM, FESEM, TEM, XRD, and STXM-NEXAFS. The results indicate that Mn2+ ions can be oxidized into Mn(IV) minerals (birnessite and pyrolusite) and Mn(III) minerals (hausmannite and feitknechtite), successively. The primary products (birnessite and pyrolusite) further transformed into hausmannite and feitknechtite under Mn2+ ion-enriched conditions. However, birnessite and pyrolusite are the end-products of the continuous microbial oxidation processes. These biogenic Mn oxides are poorly crystallized, which provides them with a high potential for usage in environmental restoration of contaminated soils and waters contaminated with heavy metals. The approaches employed in this study will also enrich genesis research of biological oxidation of Mn(II) species in nature.

    • Zircon U–Pb Geochronology and Geochemistry of the Early Cretaceous Volcanic Rocks from the Manitu Formation in the Hongol Area,Northeastern Inner Mongolia

      2017, 91(4):1286-1304.

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      Abstract:We undertook zircon U–Pb dating and geochemical analyses of volcanic rocks from the Manitu Formation in the Hongol area, northeastern Inner Mongolia, to determine their age, petrogenesis and sources, which are important for understanding the Late Mesozoic tectonic evolution of the Great Xing’an Range. The volcanic rocks of the Manitu Formation from the Hongol area consist primarily of trachyandesite, based on their chemical compositions. The zircons from two of these trachyandesites are euhedral–subhedral in shape, display clear oscillatory growth zoning and have high Th/U ratios (0.31–1.15), indicating a magmatic origin. The results of LA-ICP-MS zircon U–Pb dating indicate that the volcanic rocks from the Manitu Formation in the Hongol area formed during the early Early Cretaceous with ages of 138.9–140.5 Ma. The volcanic rocks are high in alkali (Na2O + K2O = 6.22–8.26 wt%), potassium (K2O = 2.49–4.58 wt%) and aluminium (Al2O3 = 14.27–15.88 wt%), whereas they are low in iron (total Fe2O3 = 3.76–6.53 wt%) and titanium (TiO2 = 1.02–1.61 wt%). These volcanic rocks are obviously enriched in large ion lithophile elements, such as Rb, Ba, Th and U, and light rare earth elements, and are depleted in high field strength elements, such as Nb, Ta and Ti with pronounced negative anomalies. Their Sr–Nd–Pb isotopic compositions show positive εNd(t) (+0.16‰ to+1.64‰) and low TDM(t) (694–767 Ma). The geochemical characteristics of these volcanic rocks suggest that they belong to a shoshonitic series and were likely generated from the partial melting of an enriched lithospheric mantle that was metasomatised by fluids released from a subducted slab during the closure of the Mongol–Okhotsk Ocean. Elemental and isotopic features reveal that fractional crystallization with the removal of ferromagnesian minerals, plagioclase, ilmenite, magnetite and apatite played an important role during the evolution of the magma. These shoshonitic rocks were produced by the partial melting of the enriched lithospheric mantle in an extensional regime, which resulted from the gravitational collapse following the final closure of the Mongol–Okhotsk Ocean in the Middle–Late Jurassic.

    • Metallogenic Epoch of Nonferrous Metallic and Silver Deposits in the Jiaodong Peninsula, China and its Geological Significance

      2017, 91(4):1305-1325.

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      Abstract:As China’s most important gold–producing district, the Jiaodong Peninsula also contains copper, lead–zinc, molybdenum (tungsten), and other nonferrous metal ore deposits, but the space–time and genetic relationships with gold deposits remain uncertain. To investigate the temporal relationship between these nonferrous metal and gold ore deposits, We collected the samples from a number of nonferrous metallic and silver deposits and metallogenetic rock bodies in the eastern Jiaodong Peninsula for isotopic dating. The results show that the Re-Os isotopic model ages of the Lengjia molybdenum deposit in Rongcheng range from 114.5 ± 1.8 Ma to 112.6 ± 1.5 Ma, with an average age of 113.6 ± 1.6 Ma; the LA-ICP-MS 206Pb/238U ages of 33 zircons in the sericitization porphyritic monzogranite that hosts the Tongjiazhuang silver deposit in Rongcheng range between 122 Ma and 109 Ma, with a weighted mean age of 116.04 ± 0.95 Ma; the LA-ICP-MS 206Pb/238U ages of 31 zircons in the copper metallogenic pyroxene monzodiorite that hosts the Kuangbei copper deposit in Rongcheng range from 126 Ma to 106 Ma, with a weighted mean age of 116.6 ± 1.7 Ma; and the LA-ICP-MS 206Pb/238U ages of 19 zircons in the pyroxene monzodiorite surrounding the Dadengge gold and multimetal deposit in Weihai range from 113 Ma to 110 Ma, with a weighted mean age of 111.7 ± 0.6 Ma. All these results indicate that the metallogenic ages of the silver and nonferrous metallic deposits in the Jiaodong Peninsula are in a limited range from 118 Ma to 111 Ma. Previous studies have demonstrated that the isotopic ages of gold deposits in the Jiaodong Peninsula range from 123 Ma to 110 Ma, while Weideshanian magmatism occurred between 126 Ma to 108 Ma. Both these ranges are grossly consistent with the metallogenic ages of silver and nonferrous metallic deposits in this study, suggesting that the large–scale mineralization occurred in the Early Cretaceous when magmatic activities were strong. This epoch may be linked to the lithosphere thinning and the thermo-upwelling extension in eastern China at that time. In addition, field investigation also shows that gold and nonferrous metallic deposits are distributed nearby the Weideshanian granite, with the nonferrous metallic deposits lying within or surrounding the granite pluton and the gold deposits outside the granite pluton. We propose the following mineralization scenario: In the Early Cretaceous, an intensive lithospheric extension induced partial melting and degassing of the metasomatized lithospheric mantle, which resulted in the formation of mantle–derived fluids enriched in metal elements. During the rapid process of magma ascent and intrusion, crust-derived fluids were activated by the magmatic thermal dome and served to further extract ore-forming materials from the crust. These fluids may have mixed with the mantle-derived fluid to form a crust–mantle mixing–type ore-forming fluid. The high-temperature conditions in the center or in contact with the granitic magmatic thermal dome would have been favorable for the formation of porphyry–type, skarn–type, and hydrothermal–vein–type ores, thus forming a series of Mo(W), Cu, and Pb-Zn deposits in the mid-eastern Jiaodong Peninsula. In contrast, the medium- to low-temperature conditions in the periphery of the magmatic thermal dome would have favored the deposition of gold (silver) ores under the appropriate physiochemical and structural conditions. The metallogenic epoch of the molybdenum, copper, and silver deposits, and their spatio-temporal and genetic relations to the gold deposits, as demonstrated in this study, not only provide important insights to the study of regional metallogeny, our understanding of the metallogenesis of the Jiaodong type gold deposit, and the geodynamic background of the large-scale mineralization in the Jiaodong Peninsula, but also have practical value in guiding the mineral exploration.

    • Mineralogy, Chemical Characteristics and Upgrading of Beach Ilmenite of the Top Meter of Black Sand Deposits of the Kafr Al-Sheikh Governorate, Northern Egypt

      2017, 91(4):1326-1338.

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      Abstract:Egyptian beach ilmenite occurs in a relatively high content in the naturally highly concentrated superficial black sand deposits at specific beach zones in the northern parts of the Nile Delta at Rosetta.?Microscopic study shows that the ilmenite occurs as fresh homogeneous black or heterogeneous multicoloured altered grains and exhibits three types (homogeneous, exsolved and altered) of ilmenite varieties. XRD data of ilmenite indicates their association with minor hematite and quartz, whereas leucoxene shows its association with Nb-rutile, pseudorutile and hematite.?Grain size distribution suggests a very fine sand size of >89% and 80% and a fine sand size of 10.5% and 18.3% for?fresh and altered ilmenites, respectively. The density of fresh, altered ilmenite and leucoxene concentrates varies from 2.70, 2.50 to 2.40 ton/m3, suggesting a gradual decrease from high grade fresh to leucoxene and consistent with variation in magnetic susceptibility as a consequence of the leaching of iron. Mass magnetic susceptibility reveals 97.6% of ilmenite and 92% of the altered form are obtained at 0.20 and 0.48 ampere. Fresh ilmenite exhibits variable TiO2?(47.18%) and Fe2O3T?(46.10%) with minor MnO, MgO and Cr2O3?(1.22, 1.10 and 0.51%). The altered ilmenite is higher in TiO2?(76.16%) and SiO2?(4.68%) and lower in Fe2O3T?(14.45%), MnO, MgO and Cr2O3?(0.39, 0.52 and 0.11%) compared with the fresh form.??Three concentrates of ilmenites (G1, G2 and G3) were prepared from crude ore using a Reading cross belt magnetic separator under different conditions, revealing a gradual increase of TiO2, SiO2, Al2O3?and CaO accompanied by a decrease of Fe2O3T, MgO and Cr2O3?with repetition of the separation?processes. Several ore dressing techniques were carried out to upgrade the ilmenite concentrate.

    • The Identification and Modeling of the Volcanic Weathering Crust in the Yingcheng Formation of the Xujiaweizi Fault Depression, Songliao Basin

      2017, 91(4):1339-1351.

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      Abstract:Through the analysis of core descriptions, well-logs, seismic data, geochemical data and structural settings of the volcanic rock of the Yingcheng Formation in the Xujiaweizi fault depression, Songliao Basin, and the geological section of the Yingcheng Formation in the southeast uplift area, this work determined the existence of volcanic weathering crust exists in the study area. The identification marks on the volcanic weathering crust can be recognized on the scale of core, logging, seismic, geochemistry, etc. In the study area, the structure of this crust is divided into clay layer, leached zone, fracture zone and host rocks, which are 5–118 m thick (averaging 27.5 m). The lithology of the weathering crust includes basalt, andesite, rhyolite and volcanic breccia, and the lithofacies are igneous effusive and extrusive facies. The volcanic weathering crusts are clustered together in the Dashen zone and the middle of the Xuzhong zone, whereas in the Shengshen zone and other parts of the Xuzhong zone, they have a relatively scattered distribution. It is a major volcanic reservoir bed, which covers an area of 2104.16 km2. According to the geotectonic setting of the Songliao Basin, the formation process of the weathering crust is complete. Combining the macroscopic and microscopic features of the weathering crust of the Yingcheng Formation in Xujiaweizi with the logging and three-dimensional seismic sections, we established a developmental model of the paleo uplift and a developmental model of the slope belt that coexists with the sag on the Xujiaweizi volcanic weathering crust. In addition, the relationship between the volcanic weathering crust and the formation and distribution of the oil/gas reservoir is discussed.

    • Restoration of Eroded Thickness of the Neogene Strata in the Western Qaidam Basin and Its Significance for Oil and Gas Occurrence

      2017, 91(4):1352-1362.

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      Abstract:During the Pleistocene, the western Qaidam Basin has largely experienced strong structural reconstruction and strong erosion. First, the eroded thickness of Neogene strata was restored approximately by the stratigraphic profile comparison method and plane trend surface restoring method; then, accurate calculation of erosion was recovered using vitrinite reflectance, and the erosion that was restored by the trend surface restoring method was corrected; finally, a distribution map of cumulative erosion was produced. This study marks an important achievement in that one of the most important parameters of basin tectonic evolution, sedimentary evolution, and oil and gas accumulation history has been obtained, and that a basic geological problem has been solved in the Qaidam Basin. The areas with high erosion and low erosion are shown in the map and a close relation between the distribution of oil and gas fields and erosion was recognized. Large and medium oil and gas fields are mainly distributed in areas with medium and low erosion. It is difficult to form large-scale oil and gas accumulation in areas in which erosion is more than 2000 m. The mechanism of the relation between oil and gas distribution and erosion is explained. This study will be of use in predicting the distribution of oil and gas.

    • Genesis of Dolomite from Ma55–Ma510 Sub-members of the Ordovician Majiagou Formation in the Jingxi Area in the Ordos Basin

      2017, 91(4):1363-1379.

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      Abstract:We clarified three stages of dolomitization and secondary changes by studying the petrology and geochemistry characteristics of dolomite from the Ma55–Ma510 sub-members of the Ordovician Majiagou Formation in the Jingxi area in the Ordos Basin: (1) Syngenetic microbial dolomitization is characterized by formation of dolomite with a mainly micrite structure and horse tooth-shape dolomite cements. (2) Seepage reflux dolomitization during the penecontemporaneous period superposed adjustment functions such as recrystallization and stabilization in the middle-deep burial stage, forming dolomites mainly consisting of micro crystal and powder crystal structure. (3) Powder dolomite, fine dolomite, and medium-coarse crystalline dolomite formed in pores and fractures in the middle-deep burial stage. The secondary concussive transgression-regression under a regressive background is an important condition for the occurrence of many stages of dolomitization in the study area. The basin was an occlusive epicontinental sea environment in the Ma5 member of the Ordovician Majiagou Formation sedimentary period. In the sediments, sulfate content was high, which is conducive to the preservation of microbial activity and microbial dolomitization. Micritic dolomite formed by microbial dolomitization provides good migration pathways for seepage reflux dolomitization. Affected by evaporation seawater with increased Mg/Ca ratio, seepage reflux dolomitization was widely developed and formed large-scale dolomite, and underwater uplifts and slopes are favorable areas for dolomite. In the middle-deep burial stage, dolomitizing fluid in the stratum recrystallized or stabilized the previous dolomite and formed a small amount of euhedral dolomite in the pores and fractures.

    • A Combination of N2 and CO2 Adsorption to Characterize Nanopore Structure of Organic-Rich Lower Silurian Shale in the Upper Yangtze Platform, South China: Implications for Shale Gas Sorption Capacity

      2017, 91(4):1380-1394.

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      Abstract:The pores in shales are mainly of nanometer-scale, and their pore size distribution is very important for the preservation and exploitation of shale gas. This study focused on the organic-rich Lower Silurian black shale from four wells in the Upper Yangtze Platform, and their TOC, mineralogical composition and pore characterization were investigated. Low pressure N2 and CO2 adsorption were conducted at 77.35 K and 273.15 K, respectively, and the pore structures were characterized by modified Brunauer-Emmett-Teller (BET), Dubinin-Radushkevich (DR), t-plot, Barrett-Joyner-Halenda (BJH) and density functional theory (DFT) methods and then the relationship between pore structure and shale gas sorption capacity was discussed. The results indicate that (1) The Lower Silurian shale has high TOC content of 0.92%–4.96%, high quartz content of 30.6%–69.5%, and high clays content of 24.1%–51.2%. The total specific surface area varies from 7.56 m2/g to 25.86 m2/g. Both the total specific surface area and quartz content are positively associated with the TOC content. (2) Shale samples with higher TOC content have more micropores, which results in more complex nanopore structure. Micropore volumes/surface areas and non-micropore surface areas all increase with the increasing TOC content. (3) A combination of N2 and CO2 adsorption provides the most suitable detection range (~0.3–60 nm) and has high reliability and accuracy for nanopore structure characterization. (4) The TOC content is the key factor to control the gas sorption capacity of the Lower Silurian shale in the Upper Yangtze Platform.

    • Digitized Outcrop Geomodeling of Ramp Shoals and its Reservoirs: as an Example of Lower Triassic Feixianguan Formation of Eastern Sichuan Basin

      2017, 91(4):1395-1412.

      Abstract (520) HTML (0) PDF 27.28 M (922) Comment (0) Favorites

      Abstract:Numerous hydrocarbon accumulations are found in ramp crest shoals worldwide and therefore this depositional setting has a high potential of being the hydrocarbon reservoir. In this paper, we combined digital outcrop geology and traditional geological mapping to build an outcrop-based geocellular model of the ramp-crest shoal complex of the Lower Triassic Feixianguan Formation in the Eastern Sichuan Basin. The outcrop model serves as an analogue for the subsurface reservoir of the Feixianguan Formation and illustrates the complexity of the lithofacies types, stratigraphic architecture, and reservoir heterogeneities at a scale below conventional subsurface data resolution. The studied ramp-crest shoal complex consists of thirteen types of lithofacies that can be grouped into three facies-groups corresponding to subtidal intraclastic shoal, sub- to inter-tidal oolitic shoal, and tidal flat depositional environments respectively. The stratigraphic architecture of the shoal complex shows mostly a strong progradation of the high energy facies associated with an overall decrease of accommodation space associated with relative sea level still stand. Two reservoir facies associations have been recognized. The first one consists of supratidal dolomudstone and upper intertidal partially dolomitized oolitic packstone with anhydrite or nodules. These facies were deposited above the high energy oolitic grainstones and occurs as thin-bedded and laterally continuous layers, characterized by high porosity and low permeability. The second reservoir facies association is composed of intertidal crystalline dolomite and subtidal intraclastic bindstone that occurs stratigraphically below the oolitic grainstones. These deposits consist of massive laterally discontinuously beds, and are characterized by high porosity and high permeability. Both types of reservoir facies tend to be stacked vertically and migrated laterally with the progradation of the shoal complex. The construction of the outcrop-based 3D geological model provide a description and quantification of the facies distribution within a robust stratigraphic framework and the style and amount of reservoir heterogeneities associated with a ramp-crest shoal complex reservoir such as the one found in Lower Triassic Feixianguan Formation and Cambrian Longwangmiao Formation in Sichuan Basin or other ramp-crest reservoir worldwide.

    • Temporal and Spatial Distribution of the Late Devonian (Famennian) Strata in the Northwestern Border of the Junggar Basin, Xinjiang, Northwestern China

      2017, 91(4):1413-1437.

      Abstract (787) HTML (0) PDF 47.59 M (779) Comment (0) Favorites

      Abstract:The base of the Saerba Member (Mbr) of the Hongguleleng Formation (Fm.) probably lies in the Famennian Palmatolepis crepida Zone; the Longkou Mbr is probably a sedimentary wedge that thins out northwards; the Duguer Mbr has an approximate age from the upper part of the Pa. marginifera Zone or the Lower Pa. rugosa trachytera Zone through the top of the Pa. perlobata postera Zone; the Wulan Mbr has an age approximately corresponding to the whole Pa. gracilis expansa Zone. In the Bulongguoer section, the Lower Mbr of the Hongguleleng Fm. corresponds to Famennian Pa. crepida Zone through Pa. marginifera Zone; the Middle Mbr probably ranges from the Pa. r. trachytera Zone through the Pa. g. expansa Zone. The basal Namu Mbr of the Heishantou Fm. is probably the product during and after the Hangenberg Event in the upper part of the Siphonodella praesulcata Zone, which is still within the Devonian. In this context, the underlying Chasi Mbr may approximately correspond to the lower part of the S. praesulcata Zone (before the Hangenberg Event). Lateral distribution of strata indicates that the Upper Devonian in the Gennaren and Saerba areas each constitutes a structure of syncline, which differs from the previous recognition of a monocline structure.

    • New Data on the Age of the Yukiang (Yujiang) Formation at Liujing, Guangxi, South China

      2017, 91(4):1438-1447.

      Abstract (580) HTML (0) PDF 18.50 M (668) Comment (0) Favorites

      Abstract:The age of the Yukiang (Yujiang) Formation has been shrouded in controversy for more than 75 years. New investigation at the Liujing section, Hengxian County, Guangxi, has revealed a conodont sequence assignable to two Early Devonian conodont zonations: the Eognathodus kindlei?–Polygnathus pireneae Zone and the Polygnathus nothoperbonus Zone from oldest to youngest. The Gaoling and Mahuangling members of the Nahkaoling (Nagaoling) Formation and the overlying Xiayiling Member and lower part of the Shizhou Member of the Yukiang Formation are proven to belong to the Pragian Eognathodus kindlei?–Polygnathus pireneae Zone. The co-occurrence of Polygnathus pireneae and Pol. sokolovi in the lower part of the Shizhou Member demonstrates that this interval can be approximately correlated with the uppermost part of the Polygnathus pireneae Zone. However, precise level identification of the Pragian–Emsian Boundary (PEB) in the Liujing section remains dfficult due to the scarcity of suitable limestone samples for conodont analysis from the middle and upper parts of the Shizhou Member. The Daliancun and Liujing members of the Yukiang Formation and the lower part of the overlying Moding Formation are assigned to the Polygnathus nothoperbonus Zone with the nominal species of this biozone ranging from the bottom of the Daliancun Member to the lower part of the Moding Formation.

    • Turbidite Events Recorded in Deep-sea Core IR-GC1 off Western Sumatra: Evidence from Grain-size Distribution

      2017, 91(4):1448-1456.

      Abstract (420) HTML (0) PDF 13.61 M (652) Comment (0) Favorites

      Abstract:Sediment core IR-GC1, from the abyssal basin of the Indian Ocean off Sumatra, may provide important information on depositional events related to earthquakes and tsunamis. In this study, based on a combination of grain-size analysis with lithological studies and oxygen isotope stratigraphy, seven deep-sea turbidite layers were identified, corresponding to seven turbidity events that occurred at 128–130, 105–107, 98–100, 86–87, 50–53, 37–41 and 20–29 ka. The sediments of the turbidite deposits are characterized by coarse grain sizes, poor sorting, wide kurtosis, bimodal frequency distributions and clear depositional variations. Particle size grading is also an important signature of deep-sea turbidite deposits and can be used as an indicator to identify turbidite layers. Possible triggering mechanisms for the turbidite events include tsunamis, earthquakes, volcanic eruptions and sea-level changes.

    • REVIEWS

      2017, 91(4):1456-1456.

      Abstract (333) HTML (0) PDF 0.00 Byte (0) Comment (0) Favorites

      Abstract:

    • The Distribution of Petroleum Resources and Characteristics of Main Petroliferous Basins along the Silk Road Economic Belt and the 21st-Century Maritime Silk Road

      2017, 91(4):1457-1486.

      Abstract (668) HTML (0) PDF 54.85 M (584) Comment (0) Favorites

      Abstract:The Silk Road Economic Belt and the 21st-Century Maritime Silk Road Initiative, abbreviated as the Belt and Road Initiative, is a primary development strategy of China’s future international cooperation. Especially, the energy resource cooperation, including oil and gas resources cooperation, is an important part of this initiative. The Belt and Road has undergone complicated geological evolution, and contains abundant mineral resources such as oil, gas, coal, uranium, iron, copper, gold and manganese ore resources. Among these, Africa holds 7.8% of the world’s total proven oil reserves. The oil and gas resources in Africa are relatively concentrated, with an overall low exploration degree and small consumption demand. Nigeria and Libya contain the most abundant oil resources in Africa, accounting for 2.2% and 2.9% of the world’s total reserves, respectively. Nigeria and Algeria hold the richest natural gas resources in Africa, occupying 2.8% and 2.4% of the world’s total reserves, respectively. Africa’s oil and gas resources are mainly concentrated in Egypt, Sultan and Western Sahara regions in the northern Africa, and the Gulf of Guinea, Niger River and Congo River area in the western Africa. The Russia–Central Asia area holds rich petroleum resources in Russia, Kazakhstan, Turkmenistan and Uzbekistan. The potential oil and gas areas include the West Siberia Basin, East Siberia Basin and sea continental shelf in Russia, the northern and central Caspian Basin in Kazakhstan, the right bank of the Amu-Darya Basin, the East Karakum uplift and the South Caspian Basin in Turkmenistan, and the Amu–Daria Basin, Fergana Basin, Afghan–Tajik Basin and North Ustyurt Basin in Uzbekistan. The Middle East oil and gas resources are mainly distributed in the Zagros foreland basin and Arabian continental margin basin, and the main oil-producing countries include Saudi Arabia, Iran and Iraq. The Asia Pacific region is a new oil and gas consumption center, with rapid growth of oil and gas demand. In 2012, this region consumed about 33.6% of the world’s total oil consumption and 18.9% of the world’s total natural gas consumption, which has been ranked the world’s largest oil and gas consumption center. The oil and gas resources are concentrated in China, Indosinian, Malaysia, Australia and India. The abundant European proven crude oil reserves are in Norway, Britain and Denmark and also rich natural gas resources in Norway, Holland and Britain. Norway and Britain contain about 77.5% of European proven oil reserves, which accounts for only 0.9% of the world’s proven reserves. The Europe includes main petroliferous basins of the Voring Basin, Anglo–Dutch Basin, Northwest German Basin, Northeast German–Polish Basin and Carpathian Basin. According to the analysis of source rocks, reservoir rocks, cap rocks and traps for the main petroliferous basins, the potential oil and gas prospecting targets in the Belt and Road are mainly the Zagros Basin and Arabic Platform in the Middle East, the East Barents Sea Basin and the East Siberia Basin in Russia–Central Asia, the Niger Delta Basin, East African rift system and the Australia Northwest Shelf. With the development of oil and gas theory and exploration technology, unconventional petroleum resources will play an increasingly important role in oil and gas industry.

    • NEWS AND HIGHLIGHTS

      2017, 91(4):1486-1486.

      Abstract (299) HTML (0) PDF 0.00 Byte (0) Comment (0) Favorites

      Abstract:

    • A Large Dinosaur Assemblage has been Discovered in Pu’an, Yunyang County, Chongqing, China

      2017, 91(4):1487-1488.

      Abstract (996) HTML (0) PDF 2.78 M (1232) Comment (0) Favorites

      Abstract:

    • RESEARCH ADVANCES

      2017, 91(4):1488-1488.

      Abstract (337) HTML (0) PDF 0.00 Byte (0) Comment (0) Favorites

      Abstract:

    • First Eggs of Fossil Bristletails (Meinertellidae: Microcoryphia)from Burmese Amber

      2017, 91(4):1489-1490.

      Abstract (1363) HTML (0) PDF 2.66 M (772) Comment (0) Favorites

      Abstract:

    • Redefining the Age of the Cenozoic Shanwang Formation in Shanwang Basin

      2017, 91(4):1491-1492.

      Abstract (601) HTML (0) PDF 2.45 M (676) Comment (0) Favorites

      Abstract:

    • Discovery of Lorandite TlAsS2 at the Distal Au–Tl Deposit in a Skarn system, Fengshan Area, Middle–Lower Yangtze River, Eastern China

      2017, 91(4):1493-1494.

      Abstract (477) HTML (0) PDF 2.94 M (650) Comment (0) Favorites

      Abstract:

    • A Discovery of ~3.1 Ga Basement in the Bohai Bay Basin

      2017, 91(4):1495-1496.

      Abstract (513) HTML (0) PDF 2.59 M (522) Comment (0) Favorites

      Abstract:

    • Discovery of the 1.8 Ga Granite on the Western Margin of the Songnen Masiff, China

      2017, 91(4):1497-1498.

      Abstract (720) HTML (0) PDF 2.51 M (712) Comment (0) Favorites

      Abstract:

    • Geochronology of the Guyang Granite-Greenstone Terrene and the Implications for Continental Crust Growth

      2017, 91(4):1499-1500.

      Abstract (558) HTML (0) PDF 2.46 M (467) Comment (0) Favorites

      Abstract:

    • New Petrological and Sedimentary Evidences on the Late Cretaceous Uplift of the Tibetan Plateau

      2017, 91(4):1501-1502.

      Abstract (559) HTML (0) PDF 2.41 M (560) Comment (0) Favorites

      Abstract:

    • The Early Breakup of Rodinia Supercontinent in the Northeastern Margin of the Yangtze Plate: New Evidence from SIMS Zircon Ages of the Granitic Gneiss from the Chaolian Island, Shandong Peninsula

      2017, 91(4):1503-1504.

      Abstract (538) HTML (0) PDF 3.17 M (633) Comment (0) Favorites

      Abstract:

    • Widespread Methane Seep Activities along the Western Slope of the Okinawa Trough, East China Sea

      2017, 91(4):1505-1506.

      Abstract (368) HTML (0) PDF 2.37 M (395) Comment (0) Favorites

      Abstract:

    • New Progress of Oil and Gas Research in the Tonghua Area, East of the Songliao Basin

      2017, 91(4):1507-1508.

      Abstract (693) HTML (0) PDF 3.32 M (656) Comment (0) Favorites

      Abstract:

    • New Discovery on Supercritical CO2-H2O Treated Coal: Pore Structure and Methane Adsorption

      2017, 91(4):1509-1010.

      Abstract (366) HTML (0) PDF 1.94 M (539) Comment (0) Favorites

      Abstract:

    • Influence of Drilling Fluid Components on Shear Strength at Cement-aquifuge Interface in Coalbed Methane Wells

      2017, 91(4):1511-1512.

      Abstract (381) HTML (0) PDF 2.48 M (468) Comment (0) Favorites

      Abstract:

    • Amplitude Non-Sensitive Stratal Dispersion Shadow for Dim Spot Reservoir Delineation

      2017, 91(4):1513-1514.

      Abstract (356) HTML (0) PDF 2.54 M (486) Comment (0) Favorites

      Abstract:

    • The Age of the Old Transgression Sequence in the Pearl River Delta, China

      2017, 91(4):1515-1516.

      Abstract (557) HTML (0) PDF 2.42 M (495) Comment (0) Favorites

      Abstract:

    • Revealing the Landform Types and Morphologic Features of Lunar Surface

      2017, 91(4):1517-1518.

      Abstract (378) HTML (0) PDF 3.01 M (615) Comment (0) Favorites

      Abstract:

Chief Editor:HOU Zengqian

Governing Body:China Association for Science and Technology

Organizer:Geological Society of China

start publication :1922

ISSN:ISSN 1000-9515

CN:CN 11-2001/P

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