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2. Acta Geologica Sinica (English Edition) Calls For Submission of Review Papers.
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EDUCATION periodicals , *GEOLOGY associations , *IMPACT factor (Citation analysis) , *AUTHORS - Abstract
The article presents brief information on a bimonthly academic journal Acta Geologica Sinica, produced by the Geological Society of China. It states that the impact factor of the journal range from 1.5 to 2.5. It further enlists several measures for author to follow guidelines such as a review paper for an article, information on scope of articles and style of presentation of paper.
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- 2014
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3. Open Access to Geological Research of China — “Geoscience Periodical Network of China”.
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GEOLOGY , *RESEARCH papers (Students) - Abstract
The article reviews the web site “Geoscience Periodical Network of China" located at www.geojournals.cn, provides geological research articles.
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- 2018
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4. The Identification and Geological Significance of Fault Buried in the Gasikule Salt Lake in China based on the Multi‐source Remote Sensing Data.
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WANG, Junhu, ZHAO, Yingjun, WU, Ding, and LU, Donghua
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SALT lakes ,REMOTE sensing ,WATER salinization ,MINES & mineral resources ,TEMPERATURE inversions ,BODIES of water ,SOIL salinity - Abstract
The salinity of the salt lake is an important factor to evaluate whether it contains some mineral resources or not, the fault buried in the salt lake could control the abundance of the salinity. Therefore, it is of great geological importance to identify the fault buried in the salt lake. Taking the Gasikule Salt Lake in China for example, the paper established a new method to identify the fault buried in the salt lake based on the multi‐source remote sensing data including Landsat TM, SPOT‐5 and ASTER data. It includes the acquisition and selection of the multi‐source remote sensing data, data preprocessing, lake waterfront extraction, spectrum extraction of brine with different salinity, salinity index construction, salinity separation, analysis of the abnormal salinity and identification of the fault buried in salt lake, temperature inversion of brine and the fault verification. As a result, the study identified an important fault buried in the east of the Gasikule Salt Lake that controls the highest salinity abnormal. Because the level of the salinity is positively correlated to the mineral abundance, the result provides the important reference to identify the water body rich in mineral resources in the salt lake. [ABSTRACT FROM AUTHOR]
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- 2021
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5. Early Cretaceous Adakitic Rocks in the Northern Great Xing'an Range, NE China: Implications for the Final Closure of Mongol‐Okhotsk Ocean and Regional Extensional Setting.
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ZHANG, Lingyu, LI, Shichao, CHU, Xiaolei, and SHANG, Yinmin
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IGNEOUS rocks ,ROCKS ,OCEANIC crust ,OCEAN ,ISOTOPIC analysis ,STRONTIUM ,RARE earth metals ,IGNEOUS provinces - Abstract
A large amount of igneous rocks in NE China formed in an extensional setting during Late Mesozoic. However, there is still controversy about how the Mongol‐Okhotsk Ocean and the Paleo‐Pacific Ocean effected the lithosphere in NE China. In this paper, we carried out a comprehensive study for andesites from the Keyihe area using LA‐ICP‐MS zircon U‐Pb dating and geochemical and Hf isotopic analysis to investigate the petrogenesis and tectonic setting of these andesites. The U‐Pb dating yields an Early Cretaceous crystallization age of 128.3±0.4 Ma. Geochemically, the andesites contain high Sr (686–930 ppm) and HREE contents, low Y (11.9–19.8 ppm) and Yb (1.08–1.52 ppm) contents, and they therefore have high Sr/Y (42–63) and La/Yb (24–36) ratios, showing the characteristics of adakitic rocks. Moreover, they exhibit high K2O/Na2O ratios (0.57–0.81), low MgO contents (0.77–3.06 wt%), low Mg# value (17–49) and negative εHf(t) values (–1.7 to –8.5) with no negative Eu anomalies, indicating that they are not related to the oceanic plate subduction. Based on the geochemical and isotopic data provided in this paper and regional geological data, it can be concluded that the Keyihe adakitic rocks were affected by the Mongol‐Okhotsk tectonic regime, forming in a transition setting from crustal thickening to regional extension thinning. They were derived from the partial melting of the thickened lower crust. The closure of the Mongol‐Okhotsk Ocean may finish in early Early Cretaceous, followed by the collisional orogenic process. The southern part region of its suture belt was in a post‐orogenic extensional setting in the late Early Cretaceous. [ABSTRACT FROM AUTHOR]
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- 2019
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6. Early Devonian Post‐collisional Granitic Magmatism in the North Qilian Orogenic Belt, Western China: Insights into Lithospheric Delamination and Orogenic Collapse.
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WANG, Qian, ZHAO, Xilin, MENG, Yuanku, YU, Shengyao, and LIU, Yanan
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OROGENIC belts , *OROGENY , *MAGMATISM , *CONTINENTAL crust , *GEOCHEMISTRY , *PETROLOGY , *URANIUM-lead dating , *ZIRCON - Abstract
Post‐collisional magmatism contains important clues for understanding the reworking and growth of continental crust, as well as lithospheric delamination and orogenic collapse. Early Devonian magmatism has been identified in the North Qilian Orogenic Belt (NQOB). This paper reports an integrated study of petrology, whole‐rock geochemistry, Sm‐Nd isotope and zircon U‐Pb dating, as well as Lu‐Hf isotopic data, for two Early Devonian intrusive plutons. The Yongchang and Chijin granites yield zircon U‐Pb ages of 394–407 Ma and 414 Ma, respectively. Both of them are characterized by weakly peraluminous to metaluminous without typical aluminium‐rich minerals, LREE‐enriched patterns with negative Eu anomalies and a negative correlation between P2O5 and SiO2 contents, consistent with geochemical features of I‐type granitoids. Zircons from the studied granites display negative to weak positive εHf(t) values (–5.7 to 2.1), which agree well with those of negative εNd(t) values (−6.4 to −2.9) for the whole‐rock samples, indicating that they were derived from the partial melting of Mesoproterozoic crust. Furthermore, low Sr/Y ratios (1.13–21.28) and high zircon saturation temperatures (745°C to 839°C, with the majority being >800°C) demonstrated a relatively shallow depth level below the garnet stability field and an additional heat source. Taken together, the Early Devonian granitic magmatism could have been produced by the partial melting of ancient crustal materials heated by mantle‐derived magmas at high‐temperature and low‐pressure conditions during post‐collisional extensional collapse. The data obtained in this study, when viewed in conjunction with previous studies, provides more information about the tectonic processes that followed the closure of the North Qilian Ocean. The tectonic transition from continental collision to post‐collisional delamination could be constrained to ∼430 Ma, which is provided by the sudden decrease of Sr/Y and La/Yb ratios and an increase in zircon εHf(t) values for granitoids. A two‐stage tectonic evolution model from continental collision to post‐collisional extensional collapse for the NQOB includes (a) continental collision and crustal thickening during ca. 455–430 Ma, characterized by granulite‐facies metamorphism and widespread low‐Mg adakitic magmatism; (b) post‐collisional delamination of thickened continental crust and extensional collapse of orogen during ca. 430–390 Ma, provided by coeval high‐Mg adakitic magmatism, A‐type granites and I‐type granitoids with low Sr‐Y ratios. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Numerical Simulation of Rainfall‐induced Xianchi Reservoir Landslide in Yunyang, Chongqing, China.
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YAN, Jinkai, MA, Yan, LIU, Lei, WANG, Zhihui, and REN, Tianxiang
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LANDSLIDES , *NATURAL disaster warning systems , *BUILDING evacuation , *PORE water pressure , *DEBRIS avalanches , *COMPUTER simulation , *RAINFALL - Abstract
A calamitous landslide happened at 22:00 on September 1, 2014 in the Yunyang area of Chongqing City, southwest China, enforcing the evacuation of 508 people and damaging 23 buildings. The landslide volume comprised 1.44 million m3 of material in the source area and 0.4 million m3 of shoveled material. The debris flow runout extended 400 m vertically and 1600 m horizontally. The Xianchi reservoir landslide event has been investigated as follows: (1) samples collected from the main body of landslide were carried out using GCTS ring shear apparatus; (2) the parameters of shear and pore water pressure have been measured; and (3) the post‐failure characteristics of landslide have been analyzed using the numerical simulation method. The excess pore‐water pressure and erosion in the motion path are considered to be the key reasons for the long‐runout motion and the scale‐up of landslides, such as that at Xianchi, were caused by the heavy rainfall. The aim of this paper is to acquired numerical parameters and the basic resistance model, which is beneficial to improve simulation accuracy for hazard assessment for similar to potentially dangerous hillslopes in China and elsewhere. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Apatite Fission Track Thermochronology of Granite from the Xiazhuang Uranium Ore Field, South China: Implications for Exhumation History and Ore Preservation.
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SUN, Yue, CHEN, Zhengle, PAN, Jiayong, HUO, Hailong, LI, Haidong, SUN, Junjie, and XU, Guangchun
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FISSION track dating , *URANIUM-lead dating , *URANIUM , *URANIUM ores , *APATITE , *ORE deposits , *GRANITE , *ORES - Abstract
Xiazhuang uranium ore field, located in the southern part of the Nanling Metallogenic Belt, is considered one of the largest granite‐related U regions in South China. In this paper, we contribute new apatite fission track data and thermal history modeling to constrain the exhumation history and evaluate preservation potential of the Xiazhuang Uranium ore field. Nine Triassic outcrop granite samples collected from different locations of Xiazhuang Uranium ore field yield AFT ages ranging from 43 to 24 Ma with similar mean confined fission track lengths ranging from 11.8 ± 2.0 to 12.9 ± 1.9 μm and Dpar values between 1.01 and 1.51 μm. The robustness time‐temperature reconstructions of samples from the hanging wall of Huangpi fault show that the Xiazhuang Uranium ore field experienced a time of monotonous and slow cooling starting from middle Paleocene to middle Miocene (∼60–10 Ma), followed by relatively rapid exhumation in the late Miocene (∼10–5 Ma) and nearly thermal stability in the Pliocene–Quaternary (∼5–0 Ma). The amount of exhumation after U mineralization since the Middle Paleogene was estimated as ∼4.3 ± 1.8 km according to the integrated thermal history model. Previous studies indicate that the ore‐forming ages of U deposits in the Xiazhuang ore field are mainly before Middle Paleocene and the mineralization depths are more than 4.4 ± 1.2 km. Therefore, the exhumation history since middle Paleocene plays important roles in the preservation of the Xiazhuang Uranium ore field. [ABSTRACT FROM AUTHOR]
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- 2024
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9. A New Type of Rare Metal Deposit: The Yushishan Leptynite‐Type Nb‐Ta Deposit in Eastern Altun, Gansu Province, NW China.
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JIANG, Shaoyong, LIU, Tao, ZHANG, Haoxiang, CAO, Shuyun, ZHENG, Ruohong, LI, Tongguo, YU, Junpeng, and WU, Yibu
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NONFERROUS metals ,VOLCANIC ash, tuff, etc. ,TANTALUM ,URANIUM-lead dating ,NIOBIUM ,PROVINCES - Abstract
The Yusishan deposit is a newly found leptynite‐type niobium and tantalum (Nb‐Ta) deposit, which is located in the Eastern Altun of Gansu Province. The leptynite of the Neoproterozoic Aoyougou Formation occurs more than 10 km long and 3 km wide. In this paper, we carried out a detailed study of the leptynite and related mineralization. The U‐Pb dating of zircon reveals ages of 831 ± 5 Ma and 790 ± 5 Ma for the unmineralized leptynite and 491 ± 4 Ma and 455 ± 4 Ma for the mineralized leptynite. The petrographic and geochemical evidence identified the protolith of the leptynite as alkaline volcanic rocks that erupted during Neoproterozoic at ca. 830 Ma. At ca. 490 Ma, the tectono‐magmatic and metamorphic event triggered remobilization and enrichment of Nb‐Ta as well as other critical metals (REE, Zr, Hf etc) with the formation of industry orebodies in the leptynite strata. The Yushishan deposit presents many similarities with the alkaline volcanic rocks related rare metal deposits in the south Qinling of China and the Brochman, Toogni and Southern Peak Range deposits in Australian. We therefore propose that the Yushishan deposit is a new type (sub‐type) of Nb‐Ta deposit and termed as leptynite type that represents the metamorphic counterpart of the alkaline volcanic rocks related rare metal deposits. [ABSTRACT FROM AUTHOR]
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- 2022
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10. Ambient Noise Tomography of Jinan: The Migration of Groundwater and the Formation of Geothermal Water.
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LEI, Ting, LIANG, Feng, HAN, Chen, WANG, Zhihui, LI, Junlun, MA, Yan, and YAO, Huajian
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GROUNDWATER ,FRICTION velocity ,SHEAR waves ,TOMOGRAPHY ,GEOTHERMAL resources ,NOISE - Abstract
Jinan is an important city in eastern China, with rich groundwater in the region. There are four famous springs in the urban area and an abundance of geothermal water in the northern part, which makes the migration of groundwater in this area a very important issue. To study the shallow shear wave velocity structure and groundwater migration in Jinan, we utilized almost a month of continuous waveform data from 175 short period seismometers deployed by the Chinese Academy of Geological Sciences, in order to calculate the cross‐correlation function. We picked 7749 group dispersion curves and 6117 phase dispersion curves with a period range of 0.2–2 s. Through inversion, we obtained the fine three‐dimensional shear wave velocity and azimuthal anisotropy structure (0–2.4 km). Combining the results with local geological and hydrological data, the following conclusions were reached. (1) There are widespread high velocity anomalies in the region between the Qianfoshan and Wenhuaqiao faults, as well as to the east of the Wenhuaqiao Fault, which may be related to the intrusive gabbro known as the Jinan Intrusive Rock. (2) The two distinct high velocity anomalies in our model (referred to as west and east Jinan Intrusive Rock in this paper) may indicate that the Jinan Intrusive Rock was broken through crustal movement. (3) There is an obvious low velocity layer under the intrusive rock, which could be the channel of groundwater migration. The precipitation in the southern mountain region seeps down into the ground, then is blocked by the Jinan Intrusive Rock and can only progress downwards to a deeper part, where the groundwater is heated by the geothermal gradient. The heated water finally arrives at the northern part and forms geothermal water. (4) The depth of the low velocity layer beneath the Jinan Intrusive Rock varies laterally, which may indicate that the depth of the groundwater migration is different beneath the west and east Jinan Intrusive Rock. (5) There is strong azimuthal anisotropy in southern Jinan, with nearly E‐W fast orientation, which may be related to the tilt limestone layering structure. [ABSTRACT FROM AUTHOR]
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- 2022
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11. Metallogenic Age and Ore‐forming Material Sources of the Dahongshan Fe‐Cu Deposit, Yunnan Province: Insights from Molybdenite Re‐Os Dating and H‐O‐S‐Pb Isotopes.
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YE, Zifeng, YANG, Guangshu, YU, Wenxiu, CHEN, Aibing, and JIA, Fuju
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GOLD ores , *METALLOGENY , *DETERIORATION of materials , *MOLYBDENITE , *SUBMARINE volcanoes , *HYDROTHERMAL deposits , *VEINS (Geology) - Abstract
The Dahongshan Fe‐Cu (‐Au) deposit is a superlarge deposit in the Kangdian metallogenic belt, southwestern China, comprising approximately 458 Mt of Fe ores (40% Fe) and 1.35 Mt Cu. Two main types of Fe‐Cu (‐Au) mineralization are present in the Dahongshan deposit: (1) early submarine volcanic exhalation and sedimentary mineralization characterized by strata‐bound fine‐grained magnetite and banded Fe‐Cu sulfide (pyrite and chalcopyrite) hosted in the Na‐rich metavolcanic rocks; (2) late hydrothermal (‐vein) type mineralization characterized by Fe‐Cu sulfide veins in the hosted strata or massive coarse‐grained magnetite orebodies controlled by faults. While previous studies have focused primarily on the early submarine volcanic and sedimentary mineralization of the deposit, data related to late hydrothermal mineralization is lacking. In order to establish the metallogenic age and ore‐forming material source of the late hydrothermal (‐vein) type mineralization, this paper reports the Re‐Os dating of molybdenite from the late hydrothermal vein Fe‐Cu orebody and H, O, S, and Pb isotopic compositions of the hydrothermal quartz‐sulfide veins. The primary aim of this study was to establish the metallogenic age and ore‐forming material source of the hydrothermal type orebody. Results show that the molybdenite separated from quartz‐sulfide veins has a Re‐Os isochron age of 831 ± 11 Ma, indicating that the Dahongshan Fe‐Cu deposit experienced hydrothermal superimposed mineralization in Neoproterozoic. The molybdenite has a Re concentration of 99.7–382.4 ppm, indicating that the Re of the hydrothermal vein ores were primarily derived from the mantle. The δ34S values of sulfides from the hydrothermal ores are 2‰–8‰ showing multi‐peak tower distribution, suggesting that S in the ore‐forming period was primarily derived from magma and partially from calcareous sedimentary rock. Furthermore, the abundance of radioactive Pb increased significantly from ore‐bearing strata to layered and hydrothermal vein ores, which may be related to the later hydrothermal transformation. The composition of H and O isotopes within the hydrothermal quartz indicates that the ore‐forming fluid is a mixture of magmatic water and a small quantity of water. These results further indicate that the late hydrothermal orebodies were formed by the Neoproterozoic magmatic hydrothermal event, which might be related to the breakup of the Rodinia supercontinent. Mantle derived magmatic hydrothermal fluid extracted ore‐forming materials from the metavolcanic rocks of Dahongshan Group and formed the hydrothermal (‐vein) type Fe‐Cu orebodies by filling and metasomatism. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Enlightenment of the Mariana Fore‐arc Sedimentary Basin Evolution to the Subduction Process.
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XING, Lei, LI, Qianqian, MENG, Qingwei, LIU, Huaishan, WEI, Jia, LÜ, Boran, and ZHOU, Heng
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SUBDUCTION ,SEDIMENTARY basins ,ISLAND arcs ,ARCHIPELAGOES ,ENLIGHTENMENT ,SEISMIC surveys ,SUBDUCTION zones - Abstract
The Mariana subduction structure is a hot topic in ocean‐ocean subduction zone research, and its subduction mechanism has attracted wide attention from experts and scholars in China and abroad. Based on the multi‐channel seismic data of survey line MGL1204 in the Mariana fore‐arc and DSDP ocean drilling data, this paper studies the development and evolution characteristics of the structure and strata in the Cenozoic Mariana fore‐arc sedimentary basin. The Cenozoic strata are divided into six seismic sequences, with the possible era of each seismic sequence discerned, and the relationship between fault development and earthquakes analyzed. The episodic activity of the volcanic chain of the Mariana island arc is thought to control the tectonic and stratigraphic development pattern of the Cenozoic sedimentary basin in the fore‐arc. Between 16°N–19°N and 146°E–151°E, the maximum thickness of the sedimentary center of the Cenozoic fore‐arc sedimentary basin in Mariana is about 2360 m. Normal faults are developed in the area and some broke to the seabed, indicating that the Mariana island arc is still in the post‐arc expansion stage. The application of multi‐channel seismic sections in structural and stratigraphic evolution study is an important means to elucidating the Mariana subduction mechanism. [ABSTRACT FROM AUTHOR]
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- 2022
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13. Hydrocarbon Generation Characteristics of Source Rocks from Different Saline Environments in the Dongpu Depression, Bohai Bay Basin, China.
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LI, Wendu, ZHANG, Pengyuan, JIANG, Fujie, ZHANG, Yunxian, HUANG, Renda, XU, Tianwu, ZHOU, Yongshui, LI, Longlong, and JIANG, Wenli
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ORGANIC geochemistry ,KEROGEN ,PETROLEUM prospecting ,LIQUID hydrocarbons ,PETROLEUM reserves ,BRACKISH waters ,HYDROCARBONS - Abstract
The Dongpu Depression is a secondary salt‐bearing tectonic unit in the Bohai Bay Basin, eastern China. The depositional environment of this depression regarding its Paleogene strata is clearly different in plane, including the saltwater environment (SE) in the north, the freshwater environment (FE) in the south and the brackish water environment (BE) in the middle. The result of oil and gas exploration in the Dongpu Depression shows that more than 90% of the proven oil reserves are distributed in the northern saltwater environment. Previous studies indicate that the organic geochemistry characteristics and the hydrocarbon generation capacity of the source rocks are very clearly diverse under different environments, which results in the significant differences in the proved reserves between the north and the south. In order to further explore the differences in the hydrocarbon generation capacity of the source rocks under distinct depositional environments and the mechanism of their occurrence, three samples from different depositional environments (W18‐5 for SE, H7‐18 for BE, CH9 for FE) were used for confined gold tube pyrolysis experiments. The results show that the CH4 yields of W18‐5, H7‐18 and CH9 increase with increasing temperature, the maximum yields being 405.62 mg/g TOC, 388.56 mg/g TOC and 367.89 mg/g TOC, respectively. The liquid hydrocarbon yields of W18‐5, H7‐18 and CH9 firstly increase with increasing temperature and then decrease after the critical temperatures. The maximum yields of C6–14 are 149.54 mg/g TOC, 140.18 mg/g TOC and 116.94 mg/g TOC, the maximum yields of C14+ being 852.4 mg/g TOC, 652.6 mg/g TOC and 596.41mg/g TOC, respectively for W18‐5, H7‐18 and CH9. To summarize, the order of hydrocarbon potential from high to low is W18‐5, H7‐18 and CH9. On this basis, through analyzing the influencing factors of hydrocarbon differences, this paper reveals that the saltwater environment is characterized by 4 factors: higher salinity, halophilic algae, high paleo‐productivity and a strongly reducing environment, which are beneficial to the enrichment of organic matter and lead to the formation of high levels of sapropelite and exinite. According to the variation of oil and gas components in the pyrolysis experiments, the hydrocarbon generation process is divided into three stages: kerogen cracking, oil cracking and C2–5 cracking. Combined with hydrocarbon generation characteristics and stages, the evolutionary model of hydrocarbon generation for source rocks under different environments is established. [ABSTRACT FROM AUTHOR]
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- 2021
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14. U‐Pb Zircon and Re‐Os Molybdenite Geochronology of the W‐Mo Mineralized Region of South Qinling, China, and their Tectonic Implications.
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HAN, Ke, YANG, Xingke, CHAO, Huixia, HE, Hujun, RUAN, Shiqi, GAO, Yunfeng, ZHANG, Weisheng, ZHU, Wei, and JIN, Gang
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GEOLOGICAL time scales ,METALLOGENY ,MOLYBDENITE ,ZIRCON ,CARBONATE rocks ,CLASTIC rocks - Abstract
A W‐Mo mineralized region is located along the northern margin of the South Qinling tectonic belt of China. W‐Mo mineralization occurs mainly in Cambrian–Ordovician clastic and carbonate rocks, and the ore bodies are structurally controlled by NW–SE‐ and NNE–SSW‐striking faults. Evidence for magmatism in the area is widespread and is dominated by intermediate–felsic intrusives or apophyses, such as the Dongjiangkou, Yanzhiba, Lanbandeng, and Sihaiping granitic bodies. Quartz‐vein‐type mineralization and fault‐controlled skarn‐type mineralization dominate the ore systems, with additional enrichment in residual deposits. At present, there are few or insufficient studies on (1) the age of mineralization, (2) the relationship between intermediate–felsic granite and W‐Mo mineralization, (3) the source of ore‐forming materials, and (4) the metallogenic and tectonic setting of the mineralized area. In this paper, we present geochronology results for numerous intrusive granitic bodies in the South Qinling tectonic belt. U‐Pb zircon geochronology of the Lanbandeng monzogranite and Wangjiaping biotite monzogranite yields ages of 222.7 ± 2.3 and 201.9 ± 1.8 Ma, respectively. In contrast to the Late Triassic age of the Lanbandeng monzogranite, the age of the newly discovered Wangjiaping biotite monzogranite places it at the Triassic–Jurassic boundary. Re‐Os molybdenite geochronology on the Qipangou W‐Mo deposit yielded a model age of 199.7 ± 3.9 Ma, indicating the deposit formed in the early Yanshanian period of the Early Jurassic. Granitoid intrusions in the mineralized area are characterized by composite granite bodies that crystallized at ca. 240–190 Ma. While there were multiple stages of intrusion, most occurred at 210–220 Ma, with waning magmatic activity at 200–190 Ma. The Re‐Os age of molybdenite in the region is ca. 200–190 Ma, which may represent a newly discovered period of W‐Mo metallogenesis that occurred during the final stages of magmatism. The heat associated with this magmatism drove ore formation and might have provided additional ore‐forming components for metallogenesis (represented by the Wangjiaping biotite monzogranite). Ore materials in the mineralized area were derived from mixed crustal and mantle sources. Enrichment of the region occurred during intracontinental orogenesis in the late Indosinian–Yanshanian, subsequent to the main Indosinian collision. At this time, the tectonic environment was dominated by extension and strike‐slip motion. [ABSTRACT FROM AUTHOR]
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- 2021
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15. Deployment and Exploration of a Gas Storage Well Pattern Based on the Threshold Radius.
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TANG, Ligen, ZHU, Weiyao, ZHU, Huayin, SUN, Chunhui, YANG, Fenglai, WANG, Yan, Li, Xiaorui, Li, Haiming, CHU, Guangzhen, WANG, Jieming, KONG, Debin, YUE, Ming, LIU, Yuwei, and HUANG, Kun
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GAS storage ,NATURAL gas prospecting ,GAS condensate reservoirs ,INJECTION wells ,GAS reservoirs ,GAS injection ,GAS wells ,HORIZONTAL wells - Abstract
To tackle the problem that wells that are deployed in a specific pattern based on the requirements of gas reservoir development are not suitable for gas storage, we have conducted concentrically circular injection and production simulation experiments for gas storage, discovered the existence of a threshold radius, denoted by Rt, and derived the expression for Rt. Based on the analysis and discussion results, we propose a strategy for deploying gas storage wells in specific patterns. The expression for Rt shows that it is affected by factors such as the gas storage gas production/injection time, the upper pressure limit, the lower pressure limit, the bottomhole flow pressure at the ends of injection and production, the and permeability. The analysis and discussion results show that the Rt of a gas storage facility is much smaller than the Rt for gas reservoir development. In the gas storage facilities in China, the Rt for gas production is less than the Rt for the gas injection, and Rt increases with the difference in the operating pressure and with permeability K. Based on the characteristics of Rt, we propose three suggestions for gas storage well pattern deployment: (1) calculate Rt according to the designed functions of the gas storage facility and deploy the well pattern according to Rt; (2) deploy sparser, large‐wellbore patterns in high‐permeability areas and denser, small‐wellbore patterns in high‐permeability areas; and (3) achieve the gas injection well pattern by new drilling, and the gas production well pattern through a combination of the gas injection well pattern and old wells. By assessing a gas storage facility with a perfect well pattern after a number of adjustments, we found that the Rt of the 12 wells calculated in this paper is basically close to the corresponding actual radius, which validates our method. The results of this study provide a methodological basis for well pattern deployment in new gas storage construction. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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16. Late Paleozoic Element Migration and Accumulation under Intracontinental Sinistral Strike‐slip Faulting in the West Junggar Orogenic Belt, NW China.
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WANG, Ye, CHEN, Xuanhua, NIE, Lanshi, DING, Weicui, WANG, Xueqiu, XU, Shenglin, MA, Feizhou, and HAN, Lele
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OROGENIC belts ,DIFFUSION - Abstract
The migration, accumulation and dispersion of elements caused by tectonic dynamics have always been a focus of attention, and become the basis of tectono‐geochemistry. However, the effects of faulting, especially strike‐slip faulting, on the adjustment of geochemical element distribution, are still not clear. In this paper, we select the West Junggar Orogenic Belt (WJOB), NW China, as a case study to test the migration behavior of elements under tectonic dynamics. The WJOB is dominated by NE‐trending large‐scale sinistral strike‐slip faults such as the Darabut Fault, the Mayile Fault, and the Baerluke Fault, which formed during the intracontinental adjustment under N–S compression during ocean‐continental conversion in the Late Paleozoic. Geochemical maps of 13 elements, Al, W, Sn, Mo, Cu, Pb, Zn, As, Sb, Hg, Fe, Ni, and Au, are analyzed for the effects of faulting and folding on element distribution at the regional scale. The results show that the element distribution in the WJOB is controlled mainly by two mechanisms during tectonic deformation: first is the material transporting mechanism, where the movement of geological units is consistent with the direction of tectonic movement; second is the diffusion mechanism, especially by tectonic pressure dissolution driven by tectonic dynamics, where the migration of elements is approximately perpendicular or opposite to the direction of tectonic movement. We conclude that the adjustment of element distributions has been determined by the combined actions of transporting and diffusion mechanisms, and that the diffusion mechanism plays an important role in the formation of geochemical Au blocks in the WJOB. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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17. Nature and Evolution of Pre‐Neoproterozoic Continental Crust in South China: A Review and Tectonic Implications.
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WANG, Kai, DONG, Shuwen, YAO, Weihua, and ZHAO, Tianyu
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RODINIA (Supercontinent) ,OROGENIC belts ,IGNEOUS rocks ,ARCHAEAN ,CONTINENTAL crust ,SEDIMENTARY rocks - Abstract
South China as an amalgamation of the Yangtze and Cathaysia blocks is composed of Archean to Mesoproterozoic basement overlain by Neoproterozoic and younger cover. Both the constituent Yangtze and Cathaysia blocks contain well‐preserved Neoproterozoic rocks that have been extensively studied in terms of the age and tectonic nature, but less is known about their earlier crustal history due to the incomplete rock record. Recent efforts in investigating the yet survived crustal nature based on isotopic and elemental signatures preserved in igneous and sedimentary rocks have steadily improved our knowledge about the pre‐Neoproterozoic continental crustal evolution in South China. In this paper, we summarize the up‐to‐date pre‐Neoproterozoic records, including petrological, geochronological, geochemical and geophysical data, across South China, and discuss its spatiotemporal patterns of the pre‐Neoproterozoic crust and the relevant tectonic events. While the xenocrystic/inherited and detrital zircon records suggest widespread Archean (mainly ca. 2.5 Ga) crustal components within both the Yangtze and Cathaysia blocks, exposed Archean rocks are only limited to isolated crustal provinces in the Yangtze Block. These Archean rocks are dominated by TTGs (tonalite‐trondhjemite‐granodiorite) with varied ages (3.3–2.5 Ga) and zircon Hf isotopes, indicating a compositionally heterogeneous nature of the Archean Yangtze Block and, by inference, the development of multiple ancient terranes. The early Paleoproterozoic (2.4–2.2 Ga) tectonomagmatic events characterize the western Yangtze Block and are supportive of an east‐west subdivision of the Yangtze basement, whereas the late Paleoproterozoic (2.1–1.7 Ga) orogeneses may have affected a larger area covering both the western and eastern parts of the Yangtze Block, and also the Cathaysia Block. The eastern Yangtze Block with generally northeastward‐younging late Paleoproterozoic magmatism and metamorphism likely experienced a prolonged 2.05–1.75 Ga orogenic process welding the various Archean proto‐continents, consistent with the documentation of a buried late Paleoproterozoic orogenic belt imaged by deep seismic profiling from its central part and of a slightly older ophiolitic mélange in the northern part. The Cathaysia Block was probably involved in a short‐lived 1.9–1.8 Ga orogenic event. The two orogeneses overlapped in time and may have contributed to the cratonization of a possible unified South China, and are referred to be linked with the assembly of the Nuna Supercontinent. The subsequent late Paleoproterozoic to early Mesoproterozoic rift successions and intrusions (1.7–1.5 Ga) in the southwestern Yangtze Block, and the ca. 1.43 Ga rifting in Hainan Island of the Cathaysia Block could be responses to the Nuna break‐up. Late Mesoproterozoic (1.2–1.0 Ga) magmatism of varied age and nature in different localities of the Yangtze Block is reflective of a complex tectonic process in the context of the assembly of the Rodinia Supercontinent. Similar‐aged metamorphism (1.3–1.0 Ga) is recorded in Hainan Island, reflecting the Grenvillian continental collision during the Rodinia assembly, but further studies are necessary to better constrain the late Mesoproterozoic tectonic framework of South China. [ABSTRACT FROM AUTHOR]
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- 2020
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18. Mineral Deposit Model of Cu–Fe–Au Skarn System in the Edongnan Region, Eastern China.
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XIE, Guiqing, MAO, Jingwen, ZHU, Qiaoqiao, HAN, Yingxiao, LI, Wei, DUAN, Chao, and YE, Hui
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MINES & mineral resources ,HYDROTHERMAL deposits ,SKARN ,EVAPORITES ,SEDIMENTARY rocks - Abstract
Cu and Fe skarns are the world's most abundant and largest skarn type deposits, especially in China, and Au‐rich skarn deposits have received much attention in the past two decades and yet there are few papers focused on schematic mineral deposit models of Cu–Fe–Au skarn systems. Three types of Au‐rich deposits are recognized in the Edongnan region, Middle–Lower Yangtze River metallogenic belt: ∼140 Ma Cu–Au and Au–Cu skarn deposits and distal Au–Tl deposits. 137–148 Ma Cu–Fe and 130–133 Ma Fe skarn deposits are recognized in the Edongnan region. The Cu–Fe skarn deposits have a greater contribution of mantle components than the Fe skarn deposits, and the hydrothermal fluids responsible for formation of the Fe skarn deposits involved a greater contribution from evaporitic sedimentary rocks compared to Cu–Fe skarn deposits. The carbonate‐hosted Au–Tl deposits in the Edongnan region are interpreted as distal products of Cu–Au skarn mineralization. A new schematic mineral deposit model of the Cu–Fe–Au skarn system is proposed to illustrate the relationship between the Cu–Fe–Au skarn mineralization, the evaporitic sedimentary rocks, and distal Au–Tl deposits. This model has important implications for the exploration for carbonate–hosted Au–Tl deposits in the more distal parts of Cu–Au skarn systems, and Fe skarn deposits with the occurrence of gypsum‐bearing host sedimentary rocks in the MLYRB, and possibly elsewhere. [ABSTRACT FROM AUTHOR]
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- 2020
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19. Ordovician Proto–basin in South China and its Tectonic Implications: Evidence from the Detrital Zircon U–Pb Ages of the Ordovician in Central Hunan, China.
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ZHANG, Jibiao, NI, Jingbo, LIU, Yanxue, ZHANG, Heng, and BU, Ling
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ZIRCON ,RODINIA (Supercontinent) ,SEDIMENTARY basins ,CONTINENTAL margins ,URANIUM-lead dating ,PROVENANCE (Geology) - Abstract
Caledonian orogeny is another important tectonic event in South China Block after the breakup of the Rodinia supercontinent. With a view to constrain the tectonic evolution and proto–basin in South China, this paper reports the geochemical and zircon U‐Pb dating data of the Ordovician strata in central Hunan, South China. Geochemical features and paleocurrent directions suggest that the lower Ordovician deposited in a passive continental margin basin with a provenance of quartzose components and showing an affinity with the Yangtze Block. U‐Pb age data for 260 detrital zircons from upper Ordovician identify three major age populations as: 900–1200 Ma, 1400–1800 Ma and 2400–2700 Ma. The detrital zircon age spectrum as well as the paleocurrent directions suggest that upper Ordovician deposited in a foreland basin and showing a close affinity with the Cathaysia Block. It is also suggest that the lower Ordovician continuously accepted the mineral from the Yangtze Block, whereas the provenance of the upper Ordovician sedimentary basin changed from the Yangtze Block to the Cathaysia Block. This change implies a tectonic movement, which caused the transformation of the proto–basin in the Hunan area in SCB from passive continental margin basin to foreland basin probably took place during late Ordovician. This fact also demonstrate that the Caledonian orogeny in South China Block began no later than 453 Ma, and a new crustal evolution model is proposed. [ABSTRACT FROM AUTHOR]
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- 2020
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20. Estimation of Fracture Geometry Parameters and Characterization of Rock Mass Structure for the Beishan Area, China.
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WEI, Xiang, GUO, Ying, CHENG, Hanlie, WEI, Jianfei, ZHANG, Linlin, HUO, Liang, and HOU, Zhenkun
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RADIOACTIVE waste disposal ,RADIOACTIVE wastes ,GEOMETRY ,GAUSSIAN distribution ,ROCKS - Abstract
The accurate estimation of fracture geometry parameters and the characterization of rock mass structure are two important topics in the geological disposal system of high‐level radioactive waste (HLW). The Beishan area, as the current preselected area for China's HLW disposal, has three subareas considered to be the key survey area at the stage of site selection. In this paper, a comprehensive survey method conducted on the outcrop is developed to estimate fracture geometry parameters. Results show that fracture occurrence obeys a Fisher distribution, fracture trace length obeys a normal distribution, and the distribution of spacing obeys a negative exponential distribution. An evaluation index, Rock Mass Structure Rating (RMSR), is proposed to characterize rock mass structure for the three subareas. The results show that the Xinchang area is more suitable to act as China's HLW disposal repository site. At the same time, the index can also be applied to characterize surface rock mass structure and rock mass integrity at the site selection phase of HLW disposal. [ABSTRACT FROM AUTHOR]
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- 2020
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21. Triassic Scleractinian Corals in China: A Review of Present Knowledge.
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BO, Jingfang, YAO, Jianxin, LIAO, Weihua, and DENG, Zhanqiu
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SCLERACTINIA ,TRIASSIC Period ,MASS extinctions ,PERMIAN Period - Abstract
Scleractinian corals appeared during the Anisian period of the Triassic after the end-Permian mass extinction, which in Triassic were distinct from the Jurassic-Cretaceous scleractinian corals. The study on Triassic scleractinian coral fauna as a separate field is significant for exploring the development and evolution of modern corals and investigating environmental changes since the Mesozoic. The first Triassic coral in China was reported in 1925, and since then, nearly 25 articles dealing with taxonomy and 17 papers about fossil reports on Triassic scleractinian corals in China have been published, which refer to 60 genera and 312 species, 49 localities and 25 strata. In this paper, the history, taxonomy, localities, stratigraphic distribution, current research, and existing knowledge gaps of the Triassic scleractinian corals in China are reviewed. More specifically, the research findings of the Triassic scleractinain coral in China since 1925 are discussed; the species of the Triassic scleractian coral fossil reported in China, has been examined and its synonyms have been sorted out; the geographical distributions of the Middle and Late Triassic scleractinian corals in China are systematically treated; the Triassic coral biostratigraphy in China has been improved; and the stratigraphic ranges of existing genera and species are provided. The above conclusions are presented in the form of complete figures. At the same time, we analyzed shortcomings in current research and identified productive future research directions of the Triassic scleractinian corals in China. [ABSTRACT FROM AUTHOR]
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- 2017
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22. Stratigraphic Framework of the Cryogenian in China.
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YU, Yang, YE, Qin, ZHANG, Kexin, HE, Weihong, SONG, Bowen, XU, Yadong, KOU, Xiaohu, WANG, Jiaxuan, and YANG, Fengli
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PALEOGEOGRAPHY ,PROSPECTING ,CLIMATE change ,ORES ,MINERALS ,SEDIMENTARY basins - Abstract
The Cryogenian is a critical period in the history of the Earth. It is marked by multiple extreme climate changes that caused alternating global glacial and interglacial intervals. These dramatically changed the sedimentary system, and metal ores and source rocks distributed widely during this period. Therefore, studying the Cryogenian stratigraphic framework and sedimentary basins is important to improve the stratigraphic resolution for metal mineral and hydrocarbon prospecting and exploration in China. This review paper firstly divides three tectonic‐stratigraphic regions in China in the Cryogenian, including the tectonic‐stratigraphic regions of Great South China, Xingmeng‐Tarim, and North China. Secondly, geochronologic data and geological records are combined to clearly depict the Cryogenian sedimentary sequence of continental blocks and micro‐continental blocks in different tectonic‐stratigraphic regions. The results were used to propose a new comparison scheme of stratigraphy for the Cryogenian in China. Finally, according to differences of sedimentary evolution and tectonic evolvement, sedimentary basins and their lithofacies paleogeography are identified and summarized, respectively. [ABSTRACT FROM AUTHOR]
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- 2020
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23. Metallurgy at the Crossroads: New Analyses of Copper‐based Objects at Tianshanbeilu, Eastern Xinjiang, China.
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LIU, Cheng, LIU, Ruiliang, ZHOU, Pengcheng, LU, Chun, YANG, Zengxin, POLLARD, A. Mark, HOMMEL, Peter, MA, Jian, CUI, Jianfeng, BRAY, Peter, TONG, Jianyi, and RAWSON, Jessica
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METALLURGY ,LEAD isotopes ,ANTIMONY ,ISOTOPIC analysis ,TRACE elements ,BRONZE Age - Abstract
Tianshanbeilu is the largest Bronze Age site in eastern Xinjiang, China. Stretching across the entire second millennium BC, it performed a prominent role in connecting the Hexi corridor, Central China and the steppe. A further insight into the metallurgical tradition and the metal supply network is of vital importance to improve our understanding of its multi‐connected nature. This paper offers a new set of chemical and isotopic data on the copper‐based objects at Tianshanbeilu, including alloying elements, trace elements (impurities) and lead isotopes. Combining the concentrations of arsenic and antimony reveals that arsenic was introduced to copper partially due to the use of specific minerals tethrahedrite‐tennantite. Lead isotopes demonstrate that multiple sources of copper were employed at Tianshanbeilu and a majority of them are characterized by common lead, which appears rather different from those of the Central Plains and the Hexi corridor, but highly consistent with local ores. Surprisingly, one object at Tianshanbeilu contains the well‐known highly radiogenic lead. This object undoubtedly marks the westernmost boundary of the distribution of the highly radiogenic lead. We also anticipate that more lead isotopic analyses in NW China will further contribute to the study of the highly radiogenic lead in Central China. [ABSTRACT FROM AUTHOR]
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- 2020
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24. Timing and Processes of Ore Formation in the Qingchengzi Polymetallic Orefield, Northeast China: Evidence from 40Ar/39Ar Geochronology.
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WANG, Yinzhi, WANG, Fei, SHI, Wenbei, YANG, Liekun, and WU, Lin
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GEOLOGICAL time scales ,ORES ,MESOZOIC Era ,TRIASSIC Period ,PROTEROZOIC Era ,JURASSIC Period - Abstract
The Qingchengzi orefield is a large polymetallic ore concentration area in the Liaodong peninsula, northeastern China, that includes twelve Pb‐Zn deposits and five Au‐Ag deposits along its periphery. The ore‐forming age remains much disputed, which prevents the identification of the relationship between the mineralization and the associated magmatism. In this paper, we quantitatively present the feasibility of making ore mineral 40Ar/39Ar dating and report reliable 40Ar/39Ar ages of lamprophyre groundmass, K‐feldspar and sphalerite from the Zhenzigou deposit. Direct and indirect methods are applied to constrain the timing of mineralization, which plays a vital role in discussing the contribution of multistage magmatism to ore formation. The low‐potassium sphalerite yielded an inverse isochron age of 232.8±41.5 Ma, which features a relatively large uncertainty. Two lamprophyre groundmasses got reliable inverse isochron ages of 193.2±1.3 Ma and 152.3±1.5 Ma, respectively. K‐feldspar yielded a precise inverse isochron age of 134.9±0.9 Ma. These four ages indicate that the mineralization is closely associated with Mesozoic magmatism. Consequently, regarding the cooling age of the earliest Mesozoic Shuangdinggou intrusion (224.2±1.2 Ma) as the initial time of mineralization, we can further constrain the age of the sphalerite to 224–191 Ma. These new and existing geochronological data, combined with the interaction cutting or symbiotic relationship between the lamprophyre veins and ore veins, suggest that the Pb‐Zn‐Au‐Ag mineralization in the Qingchengzi orefield mainly occurred during three periods: the late Triassic (ca. 224–193 Ma), the late Jurassic (ca. 167–152 Ma) and the early Cretaceous (ca. 138–134 Ma). This polymetallic deposits are shown to have been formed during multiple events coinciding with periods of the Mesozoic magmatic activity. In contrast, the Proterozoic magmatism and submarine exhalative and hydrothermal sedimentation in the Liaolaomo paleorift served mainly to transport and concentrate the ore‐forming substances at the Liaohe Group with no associated Pb‐Zn‐Au‐Ag mineralization. [ABSTRACT FROM AUTHOR]
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- 2020
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25. The Sensitive Properties of Hydrate Reservoirs Based on Seismic Stereoscopic Detection Technology.
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LIU, Xueqin, XING, Lei, QIN, Zhiliang, and LIU, Huaishan
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BULK modulus ,MODULUS of rigidity ,SURFACE waves (Seismic waves) ,NATURAL gas prospecting ,GAS hydrates ,RESERVOIRS ,GAS distribution ,HEAD-mounted displays - Abstract
Higher‐precision determinations of hydrate reservoirs, hydrate saturation levels and storage estimations are important for guaranteeing the ability to continuously research, develop and utilize natural gas hydrate resources in China. With seismic stereoscopic detection technology, which fully combines the advantages of different seismic detection models, hydrate formation layers can be observed with multiangle, wide‐azimuth, wide‐band data with a high precision. This technique provides more reliable data for analyzing the distribution characteristics of gas hydrate reservoirs, establishing velocity models, and studying the hydrate‐sensitive properties of petrophysical parameters; these data are of great significance for the exploration and development of natural gas hydrate resources. Based on a velocity model obtained from the analysis of horizontal streamer velocity data in the hydrate‐bearing area of the Shenhu Sea, this paper uses three VCs (longitudinal spacing of 25 m) and four OBSs (transverse spacing of 200 m) to jointly detect seismic datasets consisting of wave points based on an inversion of traveltime imaging sections. Accordingly, by comparing the differences between the seismic phases in the original data and the forward‐modeled seismic phases, multiangle coverage constraint corrections are applied to the initial velocity model, and the initial model is further optimized, thereby improving the imaging quality of the streamer data. Petrophysical elastic parameters are the physical parameters that are most directly and closely related to rock formations and reservoir physical properties. Based on the optimized velocity model, the rock elastic hydrate‐sensitive parameters of the hydrate reservoirs in the study area are inverted, and the sensitivities of the petrophysical parameters to natural gas hydrates are investigated. According to an analysis of the inversion results obtained from these sensitive parameters, λρ, Vp and λμ are simultaneously controlled by the bulk modulus and shear modulus, while Vs and μρ are controlled only by the shear modulus, and the latter two parameters are less sensitive to hydrate‐bearing layers. The bulk modulus is speculated to be more sensitive than the shear modulus to hydrates. In other words, estimating the specific gravity of the shear modulus among the combined parameters can affect the results from the combined elastic parameters regarding hydrate reservoirs. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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26. Pore Size Distribution of a Tight Sandstone Reservoir and its Effect on Micro Pore‐throat Structure: A Case Study of the Chang 7 Member of the Xin'anbian Block, Ordos Basin, China.
- Author
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LI, Peng, JIA, Chengzao, JIN, Zhijun, LIU, Quanyou, BI, He, ZHENG, Min, WU, Songtao, and HUANG, Zhenkai
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PORE size distribution ,MERCURY ,NANOPORES ,RESERVOIRS ,FIELD emission electron microscopy ,SANDSTONE ,GEOLOGICAL carbon sequestration ,NUCLEAR magnetic resonance - Abstract
Pore distribution and micro pore‐throat structure characteristics are significant for tight oil reservoir evaluation, but their relationship remains unclear. This paper selects the tight sandstone reservoir of the Chang 7 member of the Xin'anbian Block in the Ordos Basin as the research object and analyzes the pore size distribution and micro pore‐throat structure using field emission scanning electron microscopy (FE‐SEM), high‐pressure mercury injection (HPMI), high‐pressure mercury injection, and nuclear magnetic resonance (NMR) analyses. The study finds that: (1) Based on the pore size distribution, the tight sandstone reservoir is characterized by three main patterns with different peak amplitudes. The former peak corresponds to the nanopore scale, and the latter peak corresponds to the micropore scale. Then, the tight sandstone reservoir is categorized into three types: type 1 reservoir contains more nanopores with a nanopore‐to‐micropore volume ratio of 82:18; type 2 reservoir has a nanopore‐to‐micropore volume ratio of 47:53; and type 3 reservoir contains more micropores with a nanopore‐to‐micropore volume ratio of 35:65. (2) Affected by the pore size distribution, the throat radius distributions of different reservoir types are notably offset. The type 1 reservoir throat radius distribution curve is weakly unimodal, with a relatively dispersed distribution and peak ranging from 0.01 μm to 0.025 μm. The type 2 reservoir's throat radius distribution curve is single‐peaked with a wide distribution range and peak from 0.1 μm to 0.25 μm. The type 3 reservoir's throat radius distribution curve is single‐peaked with a relatively narrow distribution and peak from 0.1 μm to 0.25 μm. With increasing micropore volume, pore‐throat structure characteristics gradually improve. (3) The correlation between micropore permeability and porosity exceeds that of nanopores, indicating that the development of micropores notably influences the seepage capacity. In the type 1 reservoir, only the mean radius and effective porosity have suitable correlations with the nanopore and micropore porosities. The pore‐throat structure parameters of the type 2 and 3 reservoirs have reasonable correlations with the nanopore and micropore porosities, indicating that the development of these types of reservoirs is affected by the pore size distribution. This study is of great significance for evaluating lacustrine tight sandstone reservoirs in China. The research results can provide guidance for evaluating tight sandstone reservoirs in other regions based on pore size distribution. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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27. Paleoproterozoic Granitoids on Liaodong Peninsula, North China Craton.
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ZHU, Kai, LIU, Zhenghong, XU, Zhongyuan, LIU, Jiexun, and WANG, Xing'an
- Subjects
BACK-arc basins ,PETROLOGY ,DIORITE ,MONZONITE ,GEOLOGICAL time scales - Abstract
Paleoproterozoic granitoids are an important constituent of the Jiao–Liao–Ji Belt (JLJB). The spatial‐temporal distribution and types of Paleoproterozoic granitoids are closely related to the evolution of the JLJB. In this paper, we review the field occurrence, petrography, geochronology, and geochemistry of Paleoproterozoic granitoids on Liaodong Peninsula, northeast China. The Paleoproterozoic granitoids can be divided into pre‐tectonic (∼2.15 Ga; peak age=2.18 Ga) and post‐tectonic (∼1.85 Ga) granitoids. The pre‐tectonic granitoids are magnetite and hornblende–biotite monzogranites and granodiorites. Pre‐tectonic monzogranites are widespread in the JLJB and have A2‐type affinities. In contrast, pre‐tectonic granodiorites are only present in the Simenzi area and have adakitic affinities. The post‐tectonic granitoids consist of porphyritic monzogranite, syenite, diorite, granodiorite, quartz monzonite, monzogranite, and granitic pegmatite, which are adakitic rocks and I‐, S‐, and A2‐type granitoids. The assemblage of pre‐tectonic A2‐type granitoids and adakitic rocks indicates the initial tectonic setting of the JLJB was a continental back‐arc basin. The assemblage of post‐tectonic adakitic rocks and I‐, S‐, and A2‐type granitoids indicates a post‐collisional setting. The 2.20–2.15 Ga A2‐type granitoids and adakitic rocks were associated with the initial stage of back‐arc extension, and the peak of back‐arc extension is inferred from the subsequent (2.15–2.10 Ga) mafic intrusive activity. The ∼1.90 Ga adakitic rocks mark the beginning of the post‐collisional stage, which was followed by the intrusion of low‐temperature S‐ and I‐type granitoids. High‐ to low‐pressure granitoids (S‐type) were generated during the peak of post‐collisional lithospheric delamination and asthenospheric upwelling. The emplacement of later granitic pegmatites occurred during the waning of the orogeny. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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28. Characteristics and Formation Mechanism of Giant Long‐Runout Landslide: A Case Study of the Gamisi Ancient Landslide in the Upper Minjiang River, China.
- Author
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GUO, Changbao, WU, Ruian, ZHANG, Yongshuang, REN, Sanshao, YANG, Zhihua, and LI, Xue
- Subjects
LANDSLIDES ,EMERGENCY management ,GEOPHYSICAL prospecting ,RIVER channels ,HAZARD mitigation ,GEOLOGICAL formations - Abstract
The upper reaches of the Minjiang River are in the eastern margin of the Tibetan Plateau, where active faults are well developed and earthquakes frequently occur. Anomalous climate change and the extremely complex geomechanical properties of rock and soil have resulted in a number of geohazards. Based on the analysis of remote sensing interpretations, geological field surveys, geophysical prospecting and geological dating results, this paper discusses the developmental characteristics of the Gamisi ancient landslide in Songpan County, Sichuan Province, and investigates its geological age and formation mechanism. This study finds that the Gamisi ancient landslide is in the periglacial region of the Minshan Mountain and formed approximately 25 ka BP. The landslide initiation zone has a collapse and slide zone of approximately 22.65×106–31.7×106 m3 and shows a maximum sliding distance of approximately 1.42 km, with an elevation difference of approximately 310 m between the back wall of the landslide and the leading edge of the accumulation area. The landslide movement was characterized by a high speed and long runout. During the sliding process, the landslide body eroded and dammed the ancient Minjiang River valley. The ancient river channel was buried 30‐60 m below the surface of the landslide accumulation area. Geophysical prospecting and drilling observations revealed that the ancient riverbed was approximately 80‐100 m thick. After the dam broke, the Minjiang River was migrated to the current channel at the leading edge of the landslide. The Gamisi ancient landslide was greatly affected by the regional crustal uplift, topography, geomorphology and paleoclimatic change. The combined action of periglacial karstification and climate change caused the limestone at the rear edge of the landslide fractured, thus providing a lithological foundation for landslide occurrence. Intense tectonic activity along the Minjiang Fault, which runs through the middle and trailing parts of the Gamisi ancient landslide, may have been the main factor inducing landsliding. Studying the Gamisi ancient landslide is of great significance for investigating the regional response to paleoclimatic change and geomorphologic evolution of the Minjiang Fault since the late Pleistocene and for disaster prevention and mitigation. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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29. Geochemistry, Monazite U–Pb Dating, and Li–Nd Isotopes of the Madi Rare Metal Granite in the Northeastern Part of the North China Craton.
- Author
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HOU, Jianglong, JIANG, Biao, and DAI, Hongzhang
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NONFERROUS metals ,NEODYMIUM isotopes ,GRANITE ,GEOCHEMISTRY ,MONAZITE ,LITHIUM ,ISLAND arcs ,BERYLLIUM - Abstract
The Madi rare metal granite is a complex massif, which contains a variety of rare metals, such as Nb, Ta, Li, and Be. In this paper, the geochemical characteristics of the granite were obtained by multi‐collector inductively coupled mass spectrometry (MC‐ICP‐MS). The precise crystalline age of the granite was obtained from monazite U‐Pb dating, and the source of the granite was determined using Li‐Nd isotopes. The Madi rare metal granite is a high‐K (calc‐alkaline), peraluminous, S‐type granite. The U‐Pb monazite age indicates that the crystalline age of the granite is 175.6 Ma, which is Early Jurassic. The granite is characterized by a relatively wide range of δ7Li values (+2.99‰ to +5.83‰) and high lithium concentrations (181 ppm to 1022 ppm). The lithium isotopic composition of the granite does not significantly correlate with the degree of magmatic differentiation. An insignificant amount of lithium isotope fractionation occurred during the granitic differentiation. The lithium isotopic composition of the granite significantly differs from that of the wall rock, but it is very similar to that of a primitive mantle peridotite xenolith (mean δ7Li value +3.5‰). The plot of Li concentration versus δ7Li indicates that the Li isotopic composition of the granite is similar to that of island arc lavas. Based on the above‐described evidence, the granite was mainly derived from the crust, but it was contaminated by a deep granitic magma. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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30. Differential Characteristics of the Upper Ordovician‐Lower Silurian Wufeng‐Longmaxi Shale Reservoir and its Implications for Exploration and Development of Shale Gas in/around the Sichuan Basin.
- Author
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WANG, Ruyue, HU, Zongquan, LONG, Shengxiang, LIU, Guangxiang, ZHAO, Jianhua, DONG, Li, DU, Wei, WANG, Pengwei, and YIN, Shuai
- Subjects
SHALE gas ,OIL shales ,SHALE ,CAP rock ,NATURAL gas prospecting ,RESERVOIRS - Abstract
The Upper Ordovician Wufeng‐Lower Silurian Longmaxi shale is widely distributed in the Sichuan Basin and its periphery, which is the key stratum for marine shale gas exploration and development (E&D) in China. Based on sedimentary environment, material basis, storage space, fracability and reservoir evolution data, the reservoir characteristics of the Wufeng‐Longmaxi shale and their significance for shale gas EE&D are systematically compared and analyzed in this paper. The results show that (1) the depocenter of the Wufeng (WF)‐Longmaxi (LM) shale gradually migrates from east to west. The high‐quality shale reservoirs in the eastern Sichuan Basin are mainly siliceous shales, which are primarily distributed in the graptolite shale interval of WF2‐LM5. The high‐quality reservoirs in the southern Sichuan Basin are mainly calcareous‐siliceous and organic‐rich argillaceous shales, which are distributed in the graptolite shale interval of WF2‐LM7. (2) Deep shale gas (the burial depth >3500 m) in the Sichuan Basin has high‐ultrahigh pressure and superior physical properties. The organic‐rich siliceous, calcareous‐siliceous and organic‐rich argillaceous shales have suitable reservoir properties. The marginal area of the Sichuan Basin has a higher degree of pressure relief, which leads to the argillaceous and silty shales evolving into direct cap rocks with poor reservoir/good sealing capacity. (3) Combining shale gas exploration practices and impacts of lithofacies, depth, pressure coefficient and brittle‐ductile transition on the reservoir properties, it is concluded that the favorable depth interval of the Wufeng‐Longmaxi shale gas is 2200∼4000 m under current technical conditions. (4) Aiming at the differential reservoir properties of the Wufeng‐Longmaxi shale in the Sichuan Basin and its periphery, several suggestions for future research directions and EE&D of shale gas are formulated. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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31. Carbon Isotopic Evolution Characteristics and the Geological Significance of the Permian Carbonate Stratotype Section in the Northern Upper‐Yangtze Region, Southern China.
- Author
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QU, Hongjun, LI, Peng, LUO, Tengwen, GUAN, Liqun, WANG, Li, and FAN, Yuhai
- Subjects
CARBON isotopes ,ISOTOPIC analysis ,GEOLOGY ,PERMIAN Period ,MASS extinctions ,FLOOD basalts - Abstract
The Permian global mass extinction events and the eruption of the Emeishan flood basalts in the Upper Yangtze region should display certain responses during the evolution of carbon isotope. In this paper, the Permian carbon isotopic evolution in the Upper Yangtze region is examined through systematic stratotype section sampling and determination of 13C in the northern Upper‐Yangtze regions and Southern China. Additionally, the carbon isotopic evolution response characteristics of the geological events in the region are evaluated, comparing the sea‐level changes in the Upper Yangtze region and the global sea‐level change curves. Results of this study indicated that the carbon isotopic curves of the Permian in the Upper Yangtze region are characterized by higher background carbon‐isotope baseline values, with three distinct negative excursions, which are located at the Middle–Late Permian boundary and the late period and end of the Late Permian. The three distinct negative excursions provide an insightful record of the global Permian mass extinction events and the eruption of the Emeishan flood basalts in the Upper Yangtze region. The first negative excursion at the Middle–Late Permian boundary reflected the eruption of the Emeishan flood basalts, a decrease in sea level, and biological extinction events of different genera in varying degrees. The second negative excursion in the Late Permian included a decrease in sea level and large‐scale biological replacement events. The third negative excursion of the carbon isotope at the end of the Permian corresponded unusually to a rise rather than a decrease in sea level, and it revealed the largest biological mass extinction event in history. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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32. Magnetochronology of Late Miocene Mammal Fauna in Xining Basin, NE Tibetan Plateau, China.
- Author
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HAN, Jian'en, SHAO, Zhaogang, CHEN, Qiguang, ZHANG, Qianqian, YU, Jia, WANG, Jin, ZHU, Dagang, XU, Biao, MENG, Qingwei, and ZHANG, Xuefeng
- Subjects
FOSSIL mammals ,GEOLOGICAL time scales ,MIOCENE stratigraphic geology ,TIBETAN chronology ,GEOLOGICAL basins - Abstract
The Xining basin is located in the northeastern margin of the Qinghai‐Tibet Plateau. It is a rift basin formed in Mesozoic and Cenozoic and structurally belongs to the intersection of Kunlun and Qilian Mountains. Cenozoic fluvial and lacustrine sedimentary strata are continuous in the Xining basin, with a thickness of more than 800 m, completely recording the deformation uplifting, weathering and denudation history and climate change process of the northeastern plateau. Currently, early Miocene Xijia fauna, early Middle Miocene Danshuilu fauna and late Middle Miocene Diaogou fauna are discovered in the Xining basin, which provide an important basis for the stratigraphic correlation of the Cenozoic strata in the Xining basin. However, in the next few decades, there are no reports about the large mammal fossils in the Xining basin, especially about late Miocene fauna. The author discovered a large amount of mammal fossils in the Neogene sedimentary strata in Huzhu area, Xining basin. According to the identification results of the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, these fossils mainly included Hipparion dongxiangense, Chilotherium sp., Parelasmotherium sp., Stephanocemas sp. and Kubanochoerus sp. and their age was early Late Miocene. Since the discovery of this set of fossils directly filled the blank that there were no large mammal fossils in the Xining basin in Late Miocene, it was very important for studying the magnetic stratigraphic chronology of fossil‐forming strata and establishing the paleomagnetic chronology scale plate of mammal fossils. In this paper, the paleomagnetic data of the fossil‐forming stratigraphic profile, Banyan profile, were measured and the paleomagnetic records were collected through high density sampling, and finally the paleomagnetic polarity column of the profile was established. The results showed that five positive and five negative polarity segments were recorded in Banyan profile, which corresponded well to the polarity between C3Br.1n‐C4n.2n in the standard polarity column. The age of profile top was about 7.25 Ma and profile bottom was about 8.4 Ma, with an age range of 1.15 Ma. The mammal fossils discovered this time were exposed between positive and negative polarities N5 and R5 at the bottom of the profile, corresponding to C4r.1r at negative polarity and C4n.2n at positive polarity in the standard polarity column. The age of mammal fossils was about 8.3 Ma. The paleomagnetic chronology of the strata and paleontological fossils determined the absolute age of late Miocene mammal fossils and expanded the upper age of late Miocene Xianshuihe Formation (N1xn) in the Xining basin, which had provided new basic data for further studying the stratigraphic deposition and correlation of late Cenozoic strata and regional environmental evolution. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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33. New Insights into the Late Triassic Nadigangri Formation of Northern Qiangtang, Tibet, China: Constraints from U‐Pb Ages and Hf Isotopes of Detrital and Magmatic Zircons.
- Author
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LI, Xueren, WANG, Jian, CHENG, Leli, FU, Xiugen, and WANG, Yuke
- Subjects
TRIASSIC paleontology ,ZIRCON analysis ,VOLCANIC eruptions ,MOUNTAINS ,GEOLOGICAL time scales - Abstract
Abstract: We report here U‐Pb age and in situ Hf isotopic results for detrital and magmatic zircons from one conglomerate and four tuffite samples from the Late Triassic Nadigangri Formation across the North Qiangtang depression, Tibet. Coupled with previously published data in the region, this paper proposes new insights into the geochronological framework for the Nadigangri Formation. The deposition ages of tuffite from top to bottom in the Woruo Mountain, Quem Co and Dongqu River, are 203 Ma, 226 Ma, 221.5 Ma and 221.1 Ma, respectively. The detrital zircons yield a younger cluster of ages of 201.5–225 Ma from the conglomerate of the Quem Co Formation. The Late Triassic Nadigangri Formation defines a temporal range approximately between 201 and 225 Ma (Norian‐Rhaetian), including three predominant groups of 220–225 Ma, 210–217 Ma and 201–205 Ma, which correspond with the three main rifting episodes of initial rifting, further rifting and final rifting. Positive
εHf (t) value and low model ages in younger detrital zircons suggests a juvenile character. However, the Hf isotopes of magmatic zircons display the presence of reworked ancient crust with 1.1–1.8 Ga. These results provide strong constraints not only on the temporal range of the Late Triassic Nadigangri Formation, but also on the onset of the Qiangtang Mesozoic rift basin. [ABSTRACT FROM AUTHOR]- Published
- 2018
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34. Geochemistry of Mercury in the Permian Tectonically Deformed Coals from Peigou Mine, Xinmi Coalfield, China.
- Author
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SONG, Dangyu, LI, Chunhui, SONG, Boyi, YANG, Cunbei, and LI, Yunbo
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COAL mining ,COAL-fired power plants ,SMELTING furnaces ,MORPHOTECTONICS ,COAL mining & the environment - Abstract
As the mercury emitted from coal combustion can lead to serious environmental issues, researchers pay more attention to the content, distribution and occurrence of mercury in coal. In this paper, the content, distribution, and occurrence of mercury in the Permian tectonically deformed coals from Peigou Mine, Xinmi coalfield, Henan Province were investigated. A total of 18 bench samples were taken from No.2-1 coals seam in Peigou Mine, including 15 coal bench samples, two roofs and one floor. The mercury concentration, mineral composition, and main inorganic element content of 18 samples were determined by DMA-80 direct mercury analyzer, XRD, and XRF respectively. The results show that the mercury content ranges from 0.047 ppm to 0.643 ppm, with an average of 0.244 ppm. Though the coal seam has turned into typical tectonically deformed coal by the strong tectonic destruction and plastic deformation, the vertical distribution of mercury has remarkable heterogeneity in coal seam section. By the analysis of correlation between mercury and the main inorganic elements and the mineral composition in coal, we infer that majority of mercury mainly relates to pyrite or kaolinite. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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35. Study of Distal Pyroclastic-flow Stratum from Tianchi Volcano in 1215 (±15) Eruption: Pyroclastic-flow Over Water.
- Author
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Bo, ZHAO, Jiandong, XU, and Chuanyong, LIN
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VOLCANIC ash, tuff, etc. ,VOLCANOES ,SCANNING electron microscopy ,HYDRATION ,ELECTRON microscopy ,TIAN Lake (China & Korea) - Abstract
In this paper, we describe three strata at the distal part of the pyroclastic-flow from the Tianchi volcano in 1215 (±15) eruption. One of the strata with crosslayers that are different from typical pyroclastic-flow strata may come from a ground-surge. The grain-size and scanning electron microscopy (SEM) analysis was performed to study the origin of the pyroclastic-flow. Characteristics of grain-size distribution show that it is similar with the ash cloud. Through the SEM analyses, we found some quench structures with less damage on the surfaces of the vitric pumices. These phenomena indicate that there has been hydration in the transportation processes at the distal of pyroclastic-flow. It has partly changed the transportation mechanism of pyroclastic-flow, which transitions form dense flow to diluted flow. This paper develops a new distal pyroclastic-flow model in the Tianchi volcano that can be divided into three stages, i.e. the quench stage, expanding stage and depositing stage. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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36. Petrogenesis and Tectonics of the Naruo Porphyry Cu(Au) Deposit Related Intrusion in the Duolong Area, Central Tibet.
- Author
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DING, Shuai, CHEN, Yuchuan, TANG, Juxing, ZHENG, Wenbao, LIN, Bin, and YANG, Chao
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PETROGENESIS ,PLATE tectonics ,PORPHYRY ,MINERAL industries ,GEODYNAMICS - Abstract
The Duolong area is the most important part of the Western Bangong-Nujiang Suture Zone porphyry Cu(Au) metallogenic belt, in Tibet, China. Here new detailed data are presented from LA-ICP-MS zircon U-Pb, whole-rock geochemical, and in-situ zircon Hf isotope analyses for igneous rocks in the large Naruo deposit (2.51 Mt of Cu and 82 t of Au) which is located ∼2 km NE of the Duolong (Duobuza and Bolong) super-large gold-rich porphyry copper deposit. We integrated our results with previous research of other porphyry deposits in the Duolong area and have identified the timing, geodynamic setting, and petrogenesis of the mineralization-associated magmatic events. Based on the measurements, the Duolong area porphyry Cu(Au) deposit formations are associated with Early Cretaceous intermediate-felsic magmatism, which is consistent with U-Pb zircon ages of 120 Ma. All the main intrusive rocks in the ore-concentrated area have similar lithogeochemical characteristics; they show a relative enrichment in both light rare earth elements (LREEs) and large-ion lithophile elements (LILEs: Rb, Ba, K, etc.) and relative depletion in both heavy rare earth elements (HREEs) and high field strength elements (HFSEs: Nb, Ta, Zr, Hf, etc.). Moreover, the granite porphyry shows positive εHf( t) values between 1.38-7.37 suggesting that magmas were potentially derived from the partial melting of a depleted mantle wedge that had been metasomatized by subducted slab-derived fluids or melts. This paper points out that the formation of the porphyry-epithermal Cu(Au) deposit in the Duolong area was dominated by northward subduction of the Bangongco Tethys Plate beneath the Qiangtang block in the Early Cretaceous (124-114 Ma), when the subducted oceanic crust reached 50-70 km underground and generated different degrees of phase transformation, which lead to a melt produced by dehydration of amphibole minerals, a metasomatized mantle wedge, and induced mantle partial melting that produced the magma. Those deposits occurred in a continental arc tectonic setting, which is similar to the continental margin arc environment of the ocean-continent subduction setting of the Andes metallogenic belt in South America. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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37. Withdrawal: Yikun LI, Qiang LI, Shiqi WANG, Manuela AIGLSTORFER, Tao DENG (2021) The Oldest Known Bovid from China and Reappraisal of the Chinese "Eotragus". Acta Geologica Sinica (English Edition); doi: 10.1111/1755-6724.14691.
- Subjects
INTERNET publishing ,BOVIDAE - Abstract
The above article from Acta Geologica Sinica‐English Edition, published online on 30 March 2021 in Wiley Online Library (http://wileyonlinelibrary.com) has been withdrawn by agreement between the authors, the Journal Deputy Editor‐in‐Chief Hongcai Fei and Geological Society of China. The withdrawal has been agreed because the paper was published online in error. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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38. Progress and Prospects of Salt Lake Research in China.
- Author
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Mianping, ZHENG, Yongsheng, ZHANG, Xifang, LIU, Wen, QI, Fanjing, KONG, Zhen, NIE, Linzhong, PU, Xianhua, HOU, Hailei, WANG, Zhen, ZHANG, Weigang, KONG, and Yongjie, LIN
- Subjects
- *
SALT lake ecology , *PALEOCLIMATOLOGY , *LAKE sediments , *CHLORIDES , *MINES & mineral resources , *STRUCTURAL geology - Abstract
China has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride-sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate (salt forming) have been identified. Five pan-lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits: the atlas (1:2500000) of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of 'Continental Potash Deposition Theory'; several new types of Mg-borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, the kurnakovite bed in Lake Nyer, and the corresponding model of borate deposition from the cooling and dissolution of boron rich brines was proposed based on principles of geology, physics and chemistry. The anti-floatation-cold crystallization method developed independently has improved the capacity of KCl production to 3 million tons per year for the Qarham, serving the famous brand of potash fertilizer products. One 1.2 million ton K-sulfate production Une, the biggest in the world, has been built in Lop Nor, and K-sulfate of about 1.6 million tons was produced in 2015. Supported by the new technology, Le. brine preparation in winter-cooling-solarization-isolation-lithium deposition from salt gradient solar pond' the highest lithium production base at Zabuye Lake (4421 m), Tibet, has been established, which is the first lithium production base in China that reaches the year production of 5000 tons of lithium carbonate. The concept of Salt lake agriculture (Salt land agriculture) has been established based on the mass growth of Dunaliella and other bacillus-algae and the occurrence of various halophytes in saltmarsh and salt saline-alkali lands, finding a new way to increase arable lands and develop related green industry in salt rich environments. Finally this paper presents some new thoughts for the further research and development on salt science, and the further progress in salt science and technology will facilitate the maturing of the interdisciplinary science 'Salinology'. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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39. Outline of Metallogenic Regularity of Bauxite Deposits in China.
- Author
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Lan, GAO, Jihong, LI, Denghong, WANG, Xiaoyun, XIONG, Chengwei, YI, and Meizhi, HAN
- Subjects
- *
ALUMINUM mines , *ALUMINUM ores , *METALLOGENY , *MINERAL industries , *ORE deposits - Abstract
Among the abundant aluminum ore resources in China, bauxite is dominated, which is mainly distributed in 19 provinces and regions, including Shanxi, Henan, Guizhou and Guangxi. The major deposit type of bauxite is paleo-weathering crust sedimentary type, and the other one is the accumulation type. The main metallogenic period is the late Paleozoic Era followed by the Cenozoic Era. The metallogenic tectonic background is characterized by a cratonic environment. This paper summarizes the bauxite metallogenic regularity based on the characteristics of bauxite resources, bauxite deposit type, bauxite metallogenic belt and metallogenic series in China, and 15 bauxite metallogenic belts, 8 bauxite metallogenic series and 7 bauxite ore concentrated areas were identified in the study. This paper also provides a theoretical basis for the evaluation of the potential of bauxite resources. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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40. Piezomagnetic In-situ Stress Monitoring and its Application in the Longmenshan Fault Zone.
- Author
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ZHANG, Chongyuan, WU, Manlu, CHEN, Qunce, and LIAO, Chunting
- Subjects
- *
FAULT zones , *CRUST of the earth , *REMOTE sensing in earth sciences , *IN situ (Civil engineering) , *IN situ remediation , *DATA transmission systems , *PLATE tectonics - Abstract
The relative change of in-situ stress is an inevitable outcome of differential movement among the crust plates. Conversely, changes of in-situ stress can also lead to deformation and instability of crustal rock mass, trigger activity of faults, and induce earthquakes. Hence, monitoring real-time change of in-situ stress is of great significance. Piezomagnetic in-situ stress monitoring has good and longtime applications in large engineering constructions and geoscience study fields in China. In this paper, the new piezomagnetic in-situ stress monitoring system is introduced and it not only has overall improvements in measuring cell's structure and property, stressing and orienting way, but also enhances integration and intelligence of control and data transmission system, in general, which greatly promotes installing efficiency of measuring probe and quality of monitoring data. This paper also discusses the responses of new piezomagnetic system in large earthquake events of in-situ stress monitoring station at Qiaoqi of Baoxing and Wenxian of Gansu. The monitoring data reflect adjustments and changes of tectonic stress field at the southwestern segment of and the northern area near the Longmenshan fault zone, which shows that the new system has a good performance and application prospect in the geoscience field. Data of the Qiaoqi stress-monitoring station manifest that the Lushan Earthquake did not release stress of the southwestern segment of the Longmenshan fault zone adequately and there still probably exists seismic risk in this region in the future. Combined with absolute in-situ stress measurement, carrying out long-term in-situ stress monitoring in typical tectonic position of important regions is of great importance for researchers to assess and study regional crust stability. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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41. Sustainable Development and Utilization of Mineral Resources: Primary Copper and Secondary Copper.
- Author
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WANG, Junbo, LI, Xin, and LIU, Yang
- Subjects
REGRESSION analysis ,COPPER prices ,GROSS domestic product ,COPPER ,ENERGY consumption ,INTERNATIONAL trade - Abstract
The article focuses on a research paper which conducts a regression analysis of copper resource consumption trends in China on the basis of per capita gross domestic product, unit energy consumption and import-export volume between 1990-2013. Topics discussed include impact of declining copper stock on copper supply, advantages of secondary copper resources over primary resources in terms of energy consumption and need to develop secondary copper industry to satisfy future copper demands.
- Published
- 2014
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42. Glacier Relics of the Last Glacial and Holocene Periods Discovered in the Middle‐low Mountains of Eastern China: Sedimentary Sequences and Environmental Evolution of Mengshan Mountain in Shandong Province since 80 ka.
- Author
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WANG, Zhaobo, WANG, Jiangyue, HE, Lelong, and ZHANG, Jian
- Subjects
HOLOCENE Epoch ,GLACIATION ,QUATERNARY Period ,GLACIAL landforms ,GLACIAL Epoch ,MOUNTAINS ,LOESS - Abstract
The goal of this research study is to describe academic issues which have been debated in the field of Chinese geosciences for a century. In 1922, Jonquei S. Lee (Li Siguang) discovered Quaternary glacial relics at Taihang Mountainin eastern China. In 1947, he published his research findings in the magazine Mount Lushan in Glacial Age. The research results had established three Ice Ages: Poyang (Gonzi), Dagu (Minde), and Lushan (Lisi). However, at that time, no Wurm glacial relics of the last Ice Age had been found in Lushan Mountain. Since then, the research team represented by Shi Yafeng, who is considered to be "the father of glaciers in China", questioned Jonquei S. Lee's research results and concluded that "Professor Jonquei S. Lee's Quaternary glacier research in Lushan Mountain having misread the debris flow". In 2005, the "middle‐low mountains" in eastern China were finally defined as follows: "We clearly and unambiguously believe that there were no glacial activities in the middle‐low mountainous areas of eastern China (east of 102° to 104°E; below 3,000 and 2,500 m) during the Quaternary Period". Currently, the long‐standing academic debate appears to have come to a conclusion. As of 2015, the author and others began to investigate and study the Quaternary glacial relics in Mengshan Mountain (1,156m above sea level), Shandong Province, one of the "middle‐low mountains" of eastern China. The relics have been observed to posses the systematic features of glacial erosion, trough and valley striations, and moraine deposits. The applied dating method shave confirmed that there were not only glacial relics of the last Ice Age (Wurm), but also Holocene glacial relics in the Mengshan Mountain area. Therefore, in order to further establish the corresponding relationship between the glacier, loess, stream sediment series, and MIS in the Mengshan Mountain area, a large number of chronological studies have been carried out regarding the various types of sediments in the area, and 24 dating datahave been obtained using OSL, CRN, and 14Cmethods. On this basis, the corresponding relationship between the sedimentary sequences and the MIS was established for the first time in eastern China, which in dicates the environmental changes which had occurred in eastern China since 80ka. These discoveries s and chronological study results confirm the existence of the Last Ice Age, as well as Holocene glacial relics at Mengshan Mountain, there by confirming that Quaternary glaciation had occurred in the middle‐low mountain areas of eastern China. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
43. Mesozoic 'Red Beds' and its Evolution in the Hefei Basin.
- Author
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Jiaodong, ZHANG, Xuanhua, CHEN, Qiuli, LI, Chengzhai, LIU, Bing, LI, Jie, LI, Gang, LIU, and Fenglou, REN
- Subjects
- *
MESOZOIC Era , *GEOLOGICAL basins , *SEQUENCE stratigraphy , *SEDIMENTATION & deposition - Abstract
The Hefei Basin is the largest basin in the North China landmass with complete and well-preserved Mesozoic and Cenozoic strata. In the basin there developed a suite of extremely thick 'red beds' in the Mesozoic. Owing to complex evolution processes and a lack of paleontological traces, there have been controversies regarding the division and correlation of this suite of red beds. Based on results obtained in recent years in drilling, seismic and surface geological investigations and in consideration of relationships between seismic sequences and regional tectonic events, as well as evidence in paleontology, petrology and isotopic dating, this paper preliminarily puts forward the following ideas about the sequence stratigraphic framework of the continental 'red beds' in the Hefei Basin. (1) The Zhougongshan Formation and the Yuantongshan Formation have similar lithologic, geophysical and paleontological characteristics, so we incorporate them into a single formation, called the Yuantongshan Formation, and the original Zhougongshan and Yuantongshan Formations are regarded as the upper and the lower parts of the newly defined Yuantongshan Formation. Its age is the Middle Jurassic; (2) the Zhuxiang Formation belongs to the Upper Jurassic Series and (3) the age of the Xiangdaopu Formation is the Lower Cretaceous. Furthermore, signatures of depositional evolution are analyzed in the paper based on features of seismic reflection, outcrops and drilling data. The Early and Middle Jurassic is characterized by a foreland basin, which is influenced mainly by uplift and longitudinal compression of the Dabieshan Mountains; the Lower Jurassic System has a relatively small depositional area; the Middle Jurassic strata are distributed extensively over the whole basin, marking the summit of basin development; a flexure basin is characteristic of the Late Jurassic, manifesting a joint effect of the Dabieshan and Zhangbaling Mountains with the former being more significant. In the Early Cretaceous, the Xiangdaopu Formation was distributed in the Daqiao depression, evidently affected by extension of the Tanlu fault; in the Late Cretaceous, the Hefei Basin was subjected to dismembering and the Zhangqiao Formation was distributed in the east-west direction along the downthrown side of the fault. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
44. Paleozoic and Mesozoic Basement Magmatisms of Eastern Qaidam Basin, Northern Qinghai-Tibet Plateau: LA-ICP-MS Zircon U-Pb Geochronology and its Geological Significance.
- Author
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Xuanhua, CHEN, GEHRELS, George, An, YIN, Li, LI, and Rongbao, JIANG
- Subjects
- *
MAGMATISM , *ZIRCON , *PALEOZOIC stratigraphic geology , *MESOZOIC stratigraphic geology , *THRUST faults (Geology) , *GEOLOGICAL time scales - Abstract
The eastern margin of the Qaidam Basin lies in the key tectonic location connecting the Qinling, Qilian and East Kunlun orogens. The paper presents an investigation and analysis of the geologic structures of the area and LA-ICP MS zircon U-Pb dating of Paleozoic and Mesozoic magmatisms of granitoids in the basement of the eastern Qaidam Basin on the basis of 16 granitoid samples collected from the South Qilian Mountains, the Qaidam Basin basement and the East Kunlun Mountains. According to the results in this paper, the basement of the basin, from the northern margin of the Qaidam Basin to the East Kunlun Mountains, has experienced at least three periods of intrusive activities of granitoids since the Early Paleozoic, i.e. the magmatisms occurring in the Late Cambrian (493.1±4.9 Ma), the Silurian (422.9±8.0 Ma-420.4±4.6 Ma) and the Late Permian-Middle Triassic (257.8±4.0 Ma-228.8±1.5 Ma), respectively. Among them, the Late Permian - Middle Triassic granitoids form the main components of the basement of the basin. The statistics of dated zircons in this paper shows the intrusive magmatic activities in the basement of the basin have three peak ages of 244 Ma (main), 418 Ma, and 493 Ma respectively. The dating results reveal that the Early Paleozoic magmatism of granitoids mainly occurred on the northern margin of the Qaidam Basin and the southern margin of the Qilian Mountains, with only weak indications in the East Kunlun Mountains. However, the distribution of Permo-Triassic (P-T) granitoids occupied across the whole basement of the eastern Qaidam Basin from the southern margin of the Qilian Mountains to the East Kunlun Mountains. An integrated analysis of the age distribution of P-T granitoids in the Qaidam Basin and its surrounding mountains shows that the earliest P-T magmatism (293.6-270 Ma) occurred in the northwestern part of the basin and expanded eastwards and southwards, resulting in the P-T intrusive magmatism that ran through the whole basin basement As the Cenozoic basement thrust system developed in the eastern Qaidam Basin, the nearly N-S-trending shortening and deformation in the basement of the basin tended to intensify from west to east, which went contrary to the distribution trend of N-S-trending shortening and deformation in the Cenozoic cover of the basin, reflecting that there was a transformation of shortening and thickening of Cenozoic crust between the eastern and western parts of the Qaidam Basin, i.e., the crustal shortening of eastern Qaidam was dominated by the basement deformation (triggered at the middle and lower crust), whereas that of western Qaidam was mainly by folding and thrusting of the sedimentary cover (the upper crust). [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
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45. Provenance System Analysis of the Nantun Formation of the Huhehu Sag in Hailar Basin.
- Author
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Junhui, LI, Qi'an, MENG, Shuangfang, LU, Defeng, ZHU, Haibo, WU, He, LIU, and Dazhi, ZHANG
- Subjects
PETROLEUM prospecting ,SEDIMENTARY basins ,GEOLOGICAL basins ,SANDSTONE analysis ,WATERSHEDS ,GEOLOGICAL formations ,SYSTEM analysis - Abstract
Huhehu Sag is a new battlefield for the future oil and gas exploration in the Hailar Basin. At present, exploration of this area stays at a low level and the understanding of the provenance system of the Nantun Formation is comparatively weak. So, to carry out the detailed depiction of the provenance system in the study area is significant for the sedimentary system reconstruction, for the prediction of reservoir distribution and favorable areas. Based on comprehensive analysis of paleogeomorphy, light-heavy mineral and seismic reflection features, sandstone thickness and sandstone percentage, this paper analyzes in detail the provenance system of the Nantun Formation in Huhehu Sag from various angles and levels. It shows that provenances of the Huhehu Sag mainly originated from the eastern Xilinbeier Salient and western Bayan Mountain Uplift. The provenances surrounding the lake basin converged to the center of the basin, among which, the steep slope belt and the gentle slope belt are the main provenances, and the southern uplift is a secondary one. The distribution framework of the provenance fundamentally determines the distribution rules of the depositional system and its sand body developing during the Nantun period. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
46. Dealing with the Spatial Synthetic Heterogeneity of Aquifers in the North China Plain: A Case Study of Luancheng County in Hebei Province.
- Author
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Rong, MA, Jiansheng, SHI, and Jichao, LIU
- Subjects
CASE studies ,HETEROGENEITY ,AQUIFERS ,MARKOV processes - Abstract
The complexity of alluvial-pluvial fan depositional systems makes the detailed characterization of their heterogeneity difficult, yet such a detailed characterization is commonly needed for construction of reliable groundwater models. Traditional models mainly focus on using a single aquifer property to qualitatively or semi-quantitatively characterize the heterogeneity of aquifer, so that they are unable to quantitatively reflect the synthetic heterogeneity of all aquifer properties. In this paper, we propose the heterogeneity synthetic index (HSI) for quantitative characterization of synthetic heterogeneity of an aquifer. The proposed calculation process involves four steps: (1) estimation of the hydraulic conductivity of a sediment sample using the cloud-Markov model, (2) establishment of the sedimentary microfacies distribution model through the Markov chain, (3) characterization of the distribution model of hydrogeological parameters using the improved sequential simulation method according to the 'facies-controlled modeling' technique, and (4) application of the entropy weight method to calculate the weight coefficient of the above aquifer properties. The HSI of an aquifer is calculated by superposition of these models according to the corresponding weight coefficient. This approach was applied to the Luancheng aquifer deposit in the southeast Hutuo River alluvial-pluvial fan in the North China Plain (NCP). The results have demonstrated that aquifer 3 which was formed in the middle Pleistocene has the strongest heterogeneity, with an HSI of 0.25-0.75. Aquifer 4 formed in the early Pleistocene shows an intermediate heterogeneity, with the HSI ranging 0.35-0.75. The weakest heterogeneity was found in aquifers 1 and 2 formed in the Holocene and late Pleistocene, with HSI values of 0.40-0.75 and 0.40-0.80, respectively. The heterogeneity of all the four aquifers is relatively strong in the radial direction of the Huai River alluvial-pluvial fan due to the abrupt change of microfacies. In contrast, in the radial direction of the Hutuo River alluvial-pluvial fan, the microfacies change mildly, and the continuity of hydrogeological parameters is better, which has resulted in weaker heterogeneity of the four aquifers in this direction. Findings suggest that the sedimentary environment has significant effects on the aquifer heterogeneity. Considering that there arc many aquifer properties, HSI can quantitatively characterize the synthetic heterogeneity of the aquifer and describe the influence of each aquifer property on the synthetic heterogeneity of the aquifer according to its weight coefficient. Thus the HSI approach can be successfully used to deal with the spatial heterogeneity of aquifer and provide a foundation for studies on contaminant transport. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
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47. Formation Mechanism of the Changxing Formation Gas Reservoir in the Yuanba Gas Field, Sichuan Basin, China.
- Author
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LONG Shengxiang, HUANG Renchun, LI Hongtao, YOU Yuchun, LIU Guoping, and Zhenrui, BA
- Subjects
- *
GAS reservoirs , *DOLOMITE , *GAS fields , *DIFFUSION - Abstract
In a very gentle platform-margin paleogeographic environment, platform-margin reef flat fades carbonate reservoir rocks were developed in the Changxing Formation of Yuanba field. Later weak structural evolution and diagenetic evolution caused the Changxing Formation to form lithologic traps, with good reservoirs such as dissolved bioclastic dolostone and dissolved pore dolostone. The Changxing Formation gas reservoir is a pseudo-layered porous lithologic gas reservoir under pressure depletion drive, with high H2S and moderate CO2 contents. This paper predictes that the conducting system for the Changxing Formation gas reservoir is possibly composed of the pores and microfractures in the Changxing Formation reservoir, the top erosional surface of the Changxing Formation, as well as the micropores and microfractures in the underlying formations. The Changxing Formation reservoir has experienced 3 hydrocarbon charging stages. This paper suggests that diffusion is the major formation mechanism for this gas reservoir. In the Middle and Late Yanshanian, the Yuanba area entered the major gas charging stage. The gas migrated mainly through diffusion and with the assistance of seepage flow in small faults and microfractures from the source rocks and the other oil-bearing strata to the Changxing Formation carbonate reservoir rocks, forming lithologic gas pools. In the Himalayan Epoch, the lithologic traps were uplifted as a whole without strong modification or overlapping, and were favorable for gas preservation. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
48. Sediment-hosted Pb-Zn Deposits in Southwest Sanjiang Tethys and Kangdian Area on the Western Margin of Yangtze Craton.
- Author
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Changming, WANG, Jun, DENG, Shouting, ZHANG, Chunji, XUE, Liqiang, YANG, Qingfei, WANG, and Xiang, SUN
- Subjects
- *
SEDIMENT analysis , *LEAD mining , *ZINC mining , *TETHYS (Paleogeography) , *CRATONS , *GEOLOGICAL basins , *PETROGENESIS - Abstract
The western margin of Yangtze Craton is known as a significant sediment-hosted base-metal aggregate cluster, especially for Pb-Zn deposits in China, e.g. Jinding, Daliangzi, Tianbaoshan, Kuangshanchang and Qinlinchang deposits. In comparison with the classic MVT deposits in the world, based on the basic geology of the sediment-hosted Pb-Zn deposits, this paper focuses on temporalspatial distribution of this deposit to further discuss its large scale mineralization and tectonic evolution history. In the SW Sanjiang Thethys, Jinding deposit is typically thrust fault-controlled and hosted mainly in the sandstones and breccia-bearing sandstones, whereas MVT-type deposits are controlled by lithology and faulting/fracturing with a strong preference for carbonate-hosted rocks. Most importantly, Jinding Pb-Zn deposit differs from the other types of sediment-hosted Pb-Zn deposits in which it was formed in a strongly deformed foreland basin within a continental collision zone. In the Kangdian area, the sediment-hosted Pb-Zn deposits were formed in the extensional basin on the side of the continental orogenic belt along the Yangtze Craton. Compared with classic MVT deposits, the Pb-Zn deposits in the Kangdian area belong to MVT deposits. This paper is significant not only for interpretation of the genesis of sediment-hosted Pb-Zn deposits but also for exploiting large base metal deposits in large sedimentary target areas. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
49. Genetic Features of Magnetite from the Kuangshanliangzi - Daopingzi Iron Ore Deposit, Pingchuan, Sichuan Province.
- Author
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JIANG, Manrong, ZHANG, Jun, and SUN, Teng
- Subjects
GEOLOGICAL research ,IRON ores ,ISOTOPIC analysis ,METASOMATISM ,ORE genesis (Mineralogy) - Abstract
The article focuses on a research paper analyzing the genetic features of magnetite from the Kuangshanliangzi-Daopingzi Iron Ore Deposit in Pingchuan in Sichuan Province, China. It analyzes the oxygen and hydrogen isotope of magnetite from the deposit. It also suggest that the source of iron was closely related to magmatic rocks and the genesis of iron ore deposits was mainly for cavity filling with metasomatism.
- Published
- 2014
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50. Computed X‐ray Tomography Investigation of Porosity and Permeability of the Liujiagou Formation Sandstone Exposed to CO2‐Saturated Brine.
- Author
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XUE, Quan, ZHANG, Liwei, XU, Liang, MYERS, Matthew, WHITE, Cameron, MEI, Kaiyuan, WANG, Hanwen, LI, Qi, and LI, Xiaochun
- Subjects
COMPUTED tomography ,SANDSTONE ,PERMEABILITY ,CARBON sequestration ,POROSITY ,PETROPHYSICS - Abstract
In order to improve CO2 capture, utilization and storage (CCUS) to solve carbon emission, sandstone from the Triassic Liujiagou Formation (LF) from the Ordos Basin in China was investigated using permeability tests and computed X‐ray tomography (CT) scanning. The presence of reactive minerals within the geological CO2 sequestration target storage formation can allow reaction with injected CO2, which changes the porosity and permeability of the LF beds, affecting storage effectiveness. To investigate the effect of chemical reactions on the pore structure and permeability of sandstone cores representing the LF CO2 storage, tests were conducted to analyze the changes in porosity and permeability of sandstone cores induced by CO2‐saturated brine at different reaction times (28‐day maximum reaction period). Porosity and permeability of the sandstone increased after reaction with CO2‐saturated brine due to mineral dissolution. The sandstone exhibited an increase in porosity and permeability after 15 days of reaction with CO2‐saturated brine. Moreover, there was an increase in the volume of large pores in the sandstone after the 28‐day period. The pore network of the sandstone was established through CT results, and the porosity calculated based on the obtained pore network was close to that measured in the test, demonstrating the feasibility to use CT to study the evolution of the microstructure of sandstone after long‐time exposure to CO2‐saturated brine. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
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