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Oxygen Isotope Characteristics of the Footwall Alteration Zones in the Hongtoushan Volcanogenic Massive Sulfide Deposit,Liaoning Province,China and Restoration of Their formation temperatures

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Acta Geologica Sinica(English Edition) 2011年第3期85卷 683-693页

作者： ZHENG Yuanchuan GU Lianxing TANG Xiaoqian LIU Sihai WU Changzhi LI Chunhai Institute of Geology Chinese Academy of Geological Sciences 26 Baiwanzhuang Road Beijing 10003 7 China State Key Laboratory for Endogenic Metal Deposits Research （Nanjing University）＂ Department of Earth Sciences Nanjing University Nanjing 210093 China

The Hongtoushan Volcanogenic Massive Sulphide Deposit（VMSD）occurs in the Hunbei granite-greenstone terrane,Liaoning Province,NE *** in the mining area have been metamorphosed around 3.0-2.8 Ga to upper amphibolite facies at temperatures between 600℃and 650℃.Cordierite-anthophyllite gneiss（CAG）in the Hongtoushan mining area,which occurs hundreds of meters below the ore horizon,corresponds to the metamorphosed semi-conformable alteration zone of the VMSD hydrothermal system,whereas the one immediately below the main ore layer represents the metamorphosed pipe-like alteration ***-rock oxygen isotope signatures were well preserved in both types of CAGs,although the mineral components have been entirely changed during regional ***,whole-rock oxygen isotopes can be used to estimate the formation temperature of both types of alteration *** show that the semi-conformable and pipelike alteration zones for the Hongtoushan submarine hydrothermal system were formed at 290-360℃and 285-320°C,respectively,whereas estimates for the former were slightly higher than that of the latter,indicating that the semi-conformable alteration zone represents the deep part of the Hongtoushan seafloor hydrothermal system,while the pipe-like alteration zone represents the discharge conduits for metal-rich fluids,which is closer to the seafloor.

关键词： oxygen isotope formation temperature VMSD footwall alteration zones Hongtoushan Liaoning Province

Geothermal Model of the Fore-Yenisey Sedimentary Basin——Transitional Structure between the Ancient Siberian Platform and the Young West Siberian Plate

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Acta Geologica Sinica(English Edition) 2022年第2期96卷 582-590页

作者： Dmitriy NOVIKOV Fedor DULTSEV Yuriy FILIPPOV Trofimuk Institute of Petroleum Geology and Geophysics SB RASNovosibirsk 630090Russia Novosibirsk State University Novosibirsk 630090Russia

Results of the investigation into the geothermal regime of the Fore-Yenisey sedimentary basin, formed during the collision and subsidence of the Kas-Turukhan microcontinent and the western margin of the Siberian craton in the late Neoproterozoic and early Paleozoic are reported. It was established that the structural and geothermal conditions of the upper Precambrian–Paleozoic sections are similar to those in the western regions of the Siberian platform and are characterized by rather low geothermal gradients(12.5–25.5 ℃/km). In the western parts of the basin, formation temperatures in the uppermost pre-Jurassic sediments are 50℃–85℃, decreasing eastward to 30℃–55℃. For the first time, the detailed geothermal model of the basin sedimentary fill was developed. This model allows predictions of the geothermal conditions of Earth’s interior.

关键词： geothermal model formation temperature Fore-Yenisey sedimentary basin West Siberia

Crystal Structure and Chemical Composition of Ludwigite from Vranovac Ore Deposit (Boranja Mountain,Serbia)

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Acta Geologica Sinica(English Edition) 2012年第6期86卷 1524-1538页

作者： Pavle TANCIC Radovan DIMITRIJEVIC Maja POZNANOVIC Aleksandar PACEVSKI Slobodanka SUDAR Geological Institute of Serbia Faculty of Mining and Geology Department of Mineralogy and Crystallography

The crystal structure of ludwigite from Vranovac ore deposit （Boranja Mt., Serbia） was refined using the X-ray powder diffraction （XRPD） Rietveld method in the space group Pbam to a final RB=7.45% and RF=5.26%. It has the unit cell dimensions of： a=9.2515（2） A; b=12.3109（2） A; c=3.03712 （7） A; and V=345.91（1） A3. The calculated distances and angles are mostly in good agreement with the Mg2＋-Fe2＋ substitutions across the M（1） and M（3） sites, as well as with the Fe3＋-AI3＋ replacement in the M（4） site. However, the mean observed M（2）-O distance is considerably shorter than prescribed, due to a slight increase of the Fe3＋ content in the M（2） site. Such replacement was compensated by slight increase of the Fe2＋ content in the M（4） site, resulting in the （Mg1.4sFe2＋o.46Fe3＋***.o2）2.o1 （Fe3＋o.94Fe2＋0.04Al0.02）1.00B1.00Os composition. The formation temperature was estimated to be about 500- 600C. The influences of the various chemical compositions to the crystallographic parameters, M-O distances, M（3） and M（4） sites shift, distortion parameters and estimated valences, were also studied and compared with other reference samples.

关键词： ludwigite crystal structure chemical composition M-O distances distortion parameters,ions valences comparison formation temperature

Differential Thermal Regimes of the Tarim and Sichuan Basins in China:Implications for Hydrocarbon Generation and Conservation

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Acta Geologica Sinica(English Edition) 2022年第4期96卷 1308-1322页

作者： CHANG Jian LI Dan QIU Nansheng ZHU Chuanqing ZHONG Ningning FENG Qianqian ZHANG Haizu WANG Xiang State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing 102249China College of Geosciences China University of PetroleumBeijing 102249China Research Institute of Exploration and Development Petro China Tarim Oilfield CompanyKorla 841000China

The uncertainty surrounding the thermal regimes of the ultra-deep strata in the Tarim and Sichuan basins,China,is unfavorable for further hydrocarbon *** study summarizes and contrasts the present-day and paleo heat flow,geothermal gradient and deep formation temperatures of the Tarim and Sichuan *** average heat flow of the Tarim and Sichuan basins are 42.5±7.6 mW/m^(2)and 53.8±7.6 mW/m^(2),respectively,reflecting the characteristics of’cold’and’warm’*** geothermal gradient with unified depths of 0-5,000 m,0-6,000 m and 0-7,000 m in the Tarim Basin are 21.6±2.9℃/km,20.5±2.8℃/km and 19.6±2.8℃/km,respectively,while the geothermal gradient with unified depths of 0-5,000 m,0-6,000 m and 0-7,000 m in the Sichuan Basin are 21.9±2.3℃/km,22.1±2.5℃/km and23.3±2.4℃/km *** differential change of the geothermal gradient between the Tarim and Sichuan basins with depth probably results from the rock thermal conductivity and heat production *** formation temperatures at depths of 6,000 m,7,000 m,8,000 m,9,000 m and 10,000 m in the Tarim Basin are 80℃-190℃,90℃-220℃,100℃-230℃,110℃-240℃and 120℃-250℃,respectively,while the formation temperatures at depths of 6,000 m,7,000 m,8,000 m and 9,000 m in the Sichuan Basin are 120℃-200℃,140℃-210℃,160℃-260℃and 180℃-280℃,*** horizontal distribution pattern of the ultra-deep formation temperatures in the Tarim and Sichuan basins is mainly affected by the basement relief,fault activity and hydrothermal *** thermal modeling revealed that the paleo-heat flow in the interior of the Tarim Basin decreased since the early Cambrian with an early Permian abrupt peak,while that in the Sichuan Basin experienced three stages of steady state from Cambrian to early Permian,rapidly rising at the end of the early Permian and declining since the late *** thermal regime of the Sichuan Basin was always higher than that of the Tarim Basin,which results in differential oil and gas generation

关键词： ultra-deep strata heat flow geothermal gradient formation temperature hydrocarbon generation and conservation Sichuan Basin Tarim Basin

Oxygen isotope compositions of eclogites in Rongcheng,Eastern China

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Oxygen isotope compositions of eclogites in Rongcheng,Easter...