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Discovery of granulite from the Fuping area in southern Qinling Mountains and its geological significance

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Chinese science Bulletin 1998年第16期43卷 1358-1362页

作者： Chunjing Wei Chonghui Yang Shouguang Zhang Rongshe Li Peking Univ Dept Geol Beijing 100871 Peoples R China Chinese Acad geol sci Inst Geol Beijing 100037 Peoples R China Bur geol & Explorat Shaanxi Prov Xianyang 712000 Peoples R China

Two-pyroxene-bearing granulites were discovered for the first time in the Hercynian-Indosinian metamorphic belt of the southern Qinling Mountains. The granulites occur in the lower part of the Fuping complex and are dominated by intermediate-acidic rocks intercalated with a small amount of bands and lenses of basic granulites. The main metamorphic minerals include orthopyroxene, clinopyroxene, biotite, plagioclase and quartz, and orthopyroxenes are often retrogressively transformed into amphiboles. The metamorphic conditions have been estimated to be %T%=720-780℃ and %P%=0.6 GPa. The granulite-bearing Fuping complex probably belongs to early Proterozoic in age. Whether it occurs as the crystalline basement of the southern Qinling Hercynian-Indosinian orogenic belt or as a thrusted slice in the collisional process needs further study.

关键词： granulite Fuping complex Qinling orogenic belt.

Thermal-induced polycondensation of soluble organic matter in coal of lower maturation stage

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Chinese science Bulletin 1998年第6期43卷 501-504页

作者： Chunjiang Wang Yanqing Xia Binjie Luo Chinese Acad sci Guangzhou Inst Geochem Canton 510640 Peoples R China Chinese Acad sci Lanzhou Inst Geol Lanzhou 730000 Peoples R China

A brief discussion is given to the thermal-induced polycondensation of soluble organic matter (SOM) in coal during lower maturation stage, based on laboratory simulation on hydrocarbon generation from coal and on correlation with natural maturation of coal. An essential relationship between the retrogressive variation of SOM and thermal-induced polycondensation during the lower maturation stage has been established.

关键词： coal coal-derived oil lower maturation polycondensation soluble organic matter.

Oligocarpia kepingensis *** the Lower Permian of the northern Tarim Basin,Xinjiang and its in situ spores

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Chinese science Bulletin 1999年第2期44卷 108-112,193页

作者： Yongdong Wang Xiuyuan Wu Chinese Acad sci Nanjing Inst Geol & Palaeontol Nanjing 210008 Peoples R China

A Palaeozoic gleicheniaceous fern Oligocarpia kepingensis sp. nov. is described from the Lower Permian of the northern Tarim Basin, Xinjiang, China. The material comprises fertile organs including sori, sporangia, spores and associated sterile leaf of the Sphenopteris type. The sori are circular and 0.6—0.8 mm in diameter, and each sorus consists of 4—6 oval sporangia without an indusium. A transverse annulus completely encircles the sporangium. Each sporangium produces probably 256 trilete spores resembling the dispersed genus Leiotriletes. Comparisons are made between O. kepingensis and other species of Oligocarpia in the soral organization and spores. It is reasonable to include Oligocarpia in Gleicheniaceae based on its similarities of fertile character to the extant gleicheniaceous members.

关键词： Oligocarpia Gleicheniaceae Permian Xinjiang.

An Experimental Calibration on the Sphalerite-Galena Sulfur Isotope Geothermometer

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Acta geologica Sinica(English Edition) 2003年第4期77卷 519-521页

作者： DING Tiping, ZHANG Chengxin, WAN Defang, LIU Zhijian and ZHANG Guilan institute of Mineral Resources, Chinese Academy of geological sciences, 26 Baiwanzhuang Rd.,Beijing 100037 Chinese Acad geol sci Inst Mineral Resources Beijing 100037 Peoples R China

A new experimental calibration was undertaken in this study to get a more reliable sphalerite-galena sulfur isotope geothermometer. The experimental conditions selected in study were very similar to those of natural hydrothermal solution. The high-precision SF6 method was used in sulfur isotope analyses. The obtained calibration curve for sulfur isotope fractionation between sphalerite and galena can be expressed with the equation 10001nαSp-Gn= 0.74×106T-2+0.08.

关键词： sulfur isotopes isotope geothermometer SF6 method sphalerite galena

A tentative study on the ultrastructure of the Middle Permian Acritarch Micrhystridium from western Yunnan, China

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Chinese science Bulletin 1998年第21期43卷 1823-1826页

作者： Weiping Yang Haichun Zhang Fangming Xu Chinese Acad sci Nanjing Inst Geol & Palaeontol Nanjing 210008 Peoples R China

A preliminary study on the ultrastructure of Middle Permian Acritarch Micrhystridiumfrom western Yunnan has been made using laser scanning confocal microscope (LSCM). Some quite new features about the texture and ultrastructure of this kind of Acritarch has been detected for the first time, which opens up a new application of this advanced technique to microfossil study.

关键词： microflora ultrastructure laser scanning confocal microscope.

New geological evidence of crustal thickening in the Gangdese block prior to the Indo-Asian collision

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Chinese science Bulletin 2003年第15期48卷 1604-1610页

作者： DING Lin & LAI Qingzhou institute of geology and Geophysics, Chinese Academy of sciences, Beijing 100029, China Correspondence should be addressed to Ding Lin (e-mail: dinglin@ ***) Chinese Acad sci Inst Geol & Geophys Beijing 100029 Peoples R China

Recent mapping in the Gangdese block has revealed many leucogranites that are similar to those in the High Himalaya. These leucogranites formed at ~140 Ma as indicated by monazite Th-Pb ion-microprobe dating and cooled at ~130 Ma as indicated by muscovite 40Ar/39Ar dating. In conjunction with previous structural and paleogeographic studies, the new data indicate that the Gangdese block underwent crustal thickening and associated exhumation during ~140-130 Ma. In this regard, the southern margin of Eurasia continent was comparable to the modern South American Altiplano-Puna plateau, the prime example of active ocean-continent subduction and associated thickened crust. Specifically, the early stages of crustal thickening and uplifting of the Gangdese block may result from subduction of the Neo-Tethyan Ocean. If the Tibetan Plateau would form by accretion of a series of blocks with thickened crust, an elevated topographic plateau similar to the Altiplano- Puna plateau had formed before collision between the Indian and Eurasian plates. Then the Tibetan Plateau would have quickly thickened, uplifted, and begun to extend soon after onset of the collision. Thus, the deformational mechanism of the Tibetan Plateau is not distributed shortening, but rather concentrating deformation within regions of thin crust between the accreted blocks.

关键词：地质学地壳增厚亚洲淡色花岗岩喜马拉雅山脉

Natural gas geochemistry of low evolutionary stage of mediumand small-sized basins in Yunnan Province, southwestern China

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Chinese science Bulletin 1999年第18期44卷 1709-1712页

作者： Yongchang Xu Ping Shen Jiangjing Zhen Wenhui Liu Ping Guan Chinese Acad sci Lanzhou Inst Geol Lanzhou 730000 Peoples R China Peking Univ Dept Geol Beijing 100871 Peoples R China

The biogenic gas and premature-low mature associated gases in some medium and small-sized basins of Yannan Province, such as Luliang, Yanglin, Baoshan and Jinggu basins, have beed researched. The results show that the biogenic-gas consists mainly of methane which is more than 99% in gasous hydrocarbons and of lighter carbon isotopic composition with δ13C1 values from -60.0‰ to - 75.4‰. The methane carbon isotopic compositions in the Baoshan Basin is relatively heavy (δ13C1, - 60‰-- 65‰), but those in Luliang and

关键词： low-evolution natural gas carbon isotope.

Variation of iron species in sliding mud

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Chinese science Bulletin 2002年第23期47卷 2018-2024页

作者： Guodong Zheng Sheng Xu Yuhua Lang Zifang Meng Chinese Acad sci State Key Lab Gas GeochemLanzhou Inst GeolLanzhou 730000China

Results of Mossbauer spectroscopy and ICP-AES measurement revealed a special distribution pattern of iron species in four crossing profiles of the Tertiary Formation Type of Landslides in Japan. In comparison with host rocks, the sliding mud in the landslide slip zone contains the higher ferrous iron content and/or trace pyrite, which indicates that the forming environment was relatively reducing. The total iron content also increased with an increase in ferric iron and pyrite, in contrast, decreased with an increase in ferrous iron content. The deep-gray and black mud layers formed and accumulated in various volumes within landslide slip zones are treated as the basic criteria for the slipping activity, because the soft mud saturated with groundwater is easy to create a plastic deformation.

关键词： sliding mud Mossbauer spectroscopy iron speciation total iron slip zone redox condition

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变质作用分类的历史回顾和新的试行分类雏议

岩石学报 2009年第8期25卷 1737-1748页

作者：沈其韩耿元生 Chinese Acad geol sci Inst Geol Beijing 100037 Peoples R China

根据变质作用分类研究的历史回顾和最新进展,本文介绍了一个试行的、较系统的变质作用分类方案,可分为局部性的变质作用和区域性的变质作用两个大类9个类型。局部性的变质作用包括以下5个类型:(1)接触变质作用,包括热变质作用、接触交... 详细信息

根据变质作用分类研究的历史回顾和最新进展,本文介绍了一个试行的、较系统的变质作用分类方案,可分为局部性的变质作用和区域性的变质作用两个大类9个类型。局部性的变质作用包括以下5个类型:(1)接触变质作用,包括热变质作用、接触交代变质作用和高热变质作用3个亚类;(2)低-中-高温动力变质作用,包括低-中-高温韧性剪切带变质作用和温压递进逆冲断层变质作用2个亚类;(3)冲击变质作用;(4)水热变质作用;(5)燃烧变质作用。区域性的变质作用可分为以下4个类型;(6)早前寒武纪克拉通基底变质作用-低中压-中高温区域变质作用,可分为5个亚类,分别是低-中压角闪岩相变质作用、低-中压麻粒岩相变质作用、低-中压角闪岩相-麻粒岩相变质作用、低-中压绿片岩相-角闪岩相递增的变质作用和区域超高温麻粒岩相变质作用;(7)造山带变质作用,可分为3个亚类,分别是低温-低压区域动力变质作用、碰撞造山变质作用和深俯冲高压-超高压区域变质作用;(8)埋深变质作用;(9)洋底变质作用。

关键词：热变质作用作用分类历史回顾雏议 systematic classification granulite facies metamorphism regional metamorphism 中高温区域变质作用麻粒岩相角闪岩相变质作用动力变质作用 ductile shear zone 亚类 subduction zone dynamic 区域性局部性接触变质作用冲击变质作用早前寒武纪