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Discovery and analysis of ultra-micro grinding grain texture in slipping lamellae of ductile-brittle zone

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Science china earth {2. 2004年第3期47卷 265-271页

作者： GE Heping1, SUN Yan1, LU Xiancai1, ZHU Wenbin1, GUO Jichun1, LIU Deliang2.& Chi-yuen Wang3 1. Department of earth sciences, Nanjing {2., State Key Laboratory of mineral Deposit, Nanjing 2.0093, china 2. Department of earth and Space sciences, {2. of Science and Technology of china, Hefei 2.002., china 3. Department of Geology and Geophysics, {2. of California, Berkeley, CA 9472., USA Nanjing Univ Dept Earth Sci State Key Lab Mineral Deposit Nanjing 210093 Peoples R China Univ Sci & Technol china Dept Earth & Space Sci Hefei 230026 Peoples R China Univ Calif Berkeley Dept Geol & Geophys Berkeley CA 94720 USA

Based on the observation of the deep bore cores sampled from the State of Cali-fornia, USA, preferred arranged particulate concentration belts were found in the ultra-slipping lamellae. And the same phenomenon was found again later in the bore cores from the petroleum basin in the Northern Shaanxi Province. It may be the product of the dynamic processes involv-ing tumbling, grinding and compresso-shearing functions, so the spherical particulates with ul-tra-size of nm and mm are called grinding grain. The formation of the grinding grains is related with the ductile-brittle deformation, the lateral pressure of the slipping, and the very low grade of dynamic metamorphism of the rocks. Based on the systematic analysis, it is indicated that some elements like Nb and Ta are enriched in the grinding grains in the granitic rocks because of the chemical differentiation, and that the slipping lamellae bearing grinding grains in mudstone with smear efficiency prove a perfect seal for oil and gas reservoirs. Meanwhile, the paper provides bases for the studies on the fast stick-slip movement and shear paradigm.

关键词： slipping lamellae, grinding grain texture, ductile-brittle deformation, smear efficiency.

A　New　Mid　Early　Pleistocene　Mammalian　FaunaDiscovered　in　Choukoutien，china　and　Its　Application　in　Biostratigraphy

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Journal of earth Science 1995年第1期14卷 41-47,120页

作者： Cheng Jie(Department of Geology and mineral resources,{2.,Beijing 100083)Cao Boxun(Faculty of earth sciences,{2.,Wuhan 430074)Tian MingZhong(Department of Geology and mineral resources, china Unive

This paper deals with a new Early Pleistocene micromammalian fauna found in Choukonden (Zhoukoudian) and its application in *** new locality (east cave ), discovered in 1985,is located on the north slope of the Taipingshan Hill, about 2.km northeast of the Loc.1 in Choukoutien and is about 140-150m in altitude. At this locality,abundant fossil mammals are found in thick cave-fissure deposit. This fauna comprises 30mammalian taxa. Based on the comparison of the fauna, as Well as the sporo-pollen, climate events and paleomagnetic polarity section with those in other areas,we come to the conclusion that the sediments (Taipingshan Formation) in east cave were formed during the Period about from 1.67 Ma B. P. to 0.97 Ma B. P., and the fauna is about 1.2. Ma B. P. in ags.

关键词： mid Early Pleistocene micromammalian fauna biostratigraphy Choukoutien.

The Construction of Natural Disaster Database of Alxa and Periodicity Analysis

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地学前缘 2009年第S1期16卷 300-301页

作者： Yan Zheng,Mingzhong Tian,Siwen Liu,Chao Ma school of the earth {2. and resources,china university of geosciences(Beijing),Beijing 100083,china.

A compilation of all meaningful historical data of natural-disasters taken place in Alxa of inner-Mongolia is used here for the construction of a 65 Ma high precision *** data in the database are divided into subsets ... 详细信息

关键词： Alxa natural disaster databases periodicity

Progress in technology for the 2.05 height determination of Qomolangma Feng (Mt. Everest)

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Science china earth {2. 2006年第5期49卷 531-538页

作者： CHEN Junyong1,2. YUAN Janli1,2. GUO Chunxi1,2. ZHANG Yanping1 & ZHANG Peng1,2.1. State Bureau of Surveying and Mapping, Beijing 100830, china 2. school of Geodesy and Geomatics, Wuhan {2., Wuhan 430079, china 1. State Bureau of Surveying and Mapping Beijing 100830 China 2. school of Geodesy and Geomatics Wuhan University Wuhan 430079 China

In 2.05 china carried out a new geodetic campaign for the height determination of Qo- molangma Feng——Mt. Everest (QF in short). The technical progresses in geodesy for the 2.05 campaign are presented in the paper. GPS positioning was the key technique in the campaign. After summarizing the experiences and lessons of the GPS positioning on the QF summit in the previous QF height determination campaigns, some measures were taken to raise the accuracy and reliability of the height determination with GPS techniques. In order to raise the accuracy of the height deter- mination of the QF summit with classical geodetic techniques, laser ranging was used together with the trigonometric levelling in the 2.05 campaign. It is the first time in china the thickness of the ice-snow layer on the QF summit was measured by ground penetrating radar integrated with GPS. The local gravity field and geoid in the QF area was improved on the basis of {2. gravity field model integrated with new ground gravity data, DTM data and GPS leveling data in the QF area. In the 2.05 campaign the normal height and orthometric height (height above sea level) of the snow surface of the QF summit were obtained as 8846.67 m and 8847.93 m respectively. The orthometric height of the rock surface of the QF summit is 8844.43 m,and the thickness of the ice-snow layer on the QF summit is 3.50 m.

关键词： Qomolangma Feng, Mt. Everest, height determination, GPS, gravity field, ground penetrating radar.

Geochemistry of Sedimentation and Diagenesis in Qixia Formation (Early Permian) of Badong, Hubei Province, china: Implications for T-R Cycle Interpretation

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Journal of earth Science 1999年第2期18卷 56-62页

作者： Yan Jiaxin Zhao Laishi Faculty of earth sciences,{2., Wuhan 430074 Fang Nianqiao Department of Geology and mineral resources,{2., Beijing 100083

Combined with sedimentary observation and mineralogical research on a type of drusy celestite of early diagenesis in origin, this geochemical study on the Qixia Formation at the Shuibuya Section, Badong County, Hubei Province of south china evaluates the contribution of sedimentation and diagenesis to the mass fractions of CaO, Al 2. 3, MgO, SiO 2. Fe 2. 3, Na 2., K 2., Mn, Sr, P and Ba in the carbonates. The Sr, initially released from the stabilization of carbonate calcium mineral, precipitated with sulfate ion as celestite in early diagenetic environment, where sulfate reduction was the minimum. Then it redistributed in burial diagenetic environment, where celestite was replaced by calcite. The fractions of the MgO and SiO 2.in the carbonates were mainly modified by the early dolomitization and silicification respectively. That of the Na 2. was overprinted by the burial diagenesis. Multivariate statistical analysis on data of sixty bulk rocks indicates that the mass fractions of the Al 2. 3, K 2., Fe 2. 3, Mn, CaO, P and Ba were affiliated with the sedimentary factor despite the obvious decrease of CaO during early dolomitization and silicification. Among them, the Al 2. 3 and K 2. mainly represent the detrital components. In addition, a dysaerobic sedimentary background was confirmed by trace element measurement and information derived from the formation of the celestite. This genetic discrimination facilitates the interpretation of the transgressive regressive (T R) cycle and specialities featured this unusual carbonate unit.

关键词： sedimentation diagenesis celestite geochemistry T R cycle.

"Three-Component" Digital Prospecting Method: A New Approach for mineral resources Quantitative Prediction and Assessment

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Journal of earth Science 2004年第3期 6-13页

作者： Zhao Pengda Chioa university of geosciences, Wuhan 430074,{2. Chen Jianping school of the earth sciences and resources, china university of geosciences, Beijing 100083,{2. Chen Jianguo Institute of Mathematical Geology, china university of geosciences, Wuhan 430074,{2. Zhang Shouting school of the earth sciences and resources, china university of geosciences, Beijing 100083,{2. Chen Yongqing{2. Geological Survey, Beijing 100073,{2.

Three-component" method consists of three close-connected aspects: geological anomaly, diversity of mineralization and mineral deposit spectrum. All these three concepts are not new separately, but it is a new approach to combine these three aspects in one single concept for quantitative mineral resources prediction and assessment and it is also the first time to conduct a more detailed study in each aspect. Investigation and clarification of geological anomalies, diversity of mineralization and spectrum of mineral deposits are realized by digitization and quantification of ore forming controlling factors, ore-existing symbols or marks, characteristics of mineralization and regulation of ore-genesis and laws of distribution. These procedures lead to construction of a "digital model" for mineral resources prediction and assessment.

关键词： three-component" method geological anomaly diversity of mineralization spectrum of mineral deposits.

Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

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Science china earth {2. 2008年第5期51卷 654-664页

作者： HU Guang1,2. JIN ZhangDong1 & ZHANG Fei3 1 State Key Laboratory of Loess and Quaternary Geology, Institute of earth Environment, Chinese Academy of sciences, Xi’an 710075,{2. 2.Graduate university of the Chinese Academy of sciences, Beijing 100049,{2. 3 College of resources and Environmental Science, Nanjing Agricultural university, Nanjing 2.0095,{2. State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China Graduate university of the Chinese Academy of sciences Beijing 100049 China College of resources and Env

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest china. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2. the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3) the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin

Macro-and microscopic mechanical behaviour of flow of coal samples experimentally deformed at high temperatures and pressures

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Chinese Science Bulletin 2005年第S1期50卷 59-66页

作者： LIU Junlai , YANG Guang & MA Rui State Key Laboratory of Geological Processes and mineral resources,{2., Beijing 100083, china Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education,{2., Beijing 100083, china College of earth sciences, Jilin university, Changchun 130061, china china Univ Geosci State Key Lab Geol Proc & Mineral Resources Beijing 100083 Peoples R China china Univ Geosci Minist Educ Key Lab Lithosphere Tecton & Lithoprobing Technol Beijing 100083 Peoples R China Jilin Univ Coll Earth Sci Changchun 130061 Peoples R China

Coal samples from Qinshui Basin, Shanxi, china are experimentally deformed at temperatures and confining pressures of 2.0 - 500℃and 2.0 - 500 Mpa, strain rate of 0.5×10-5/s and total strain of 10%. The vitrinite reflectance of the coal samples varies from 3.04 to 1.79. It is shown that the strengths of the deformed samples change obviously with coeval increasing temperatures and pressures (T/P). At the experimental range of T/P, the effects of increasing temperature predominate over that of increasing pressure. Microstructural analysis indicates a brittle to ductile transition under experimental T/P conditions from 2.0 to 300℃, and 2.0 to 300Mpa. Brittle deformation microstruc-tures include macroscopic fracture zones and penetrative fracture associations. Elongation, undulose or irregular extinction, deformation lamellae and dynamic recrystallization of grains are the main ductile deformation microstructures. The variation of deformation mechanisms of the experimentally deformed coal samples is related to both the components of coals and T/P conditions. At low T/P, fractures occur in both inertinite and vitrinite of the samples. At higher T/P, crystalline plastic deformations are observed in the inertinite only.

关键词： coal experimental deformation brittle to ductile transition.

Ultramafic xenoliths in Mesozoic diorite in west Shandong Province

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Science china earth {2. 2004年第6期47卷 489-499页

作者： CHEN Lihui1,2.& ZHOU Xinhua2.1.The Key Laboratory of Orogenic Belts and Crustal Evolution,Ministry of Education,china and school of {2. and Space sciences,Peking university,Beijing 100871,china 2.Institute of Geology and Geophysics,Chinese Academy of sciences,Beijing 10002.,china Correspondence should be addressed to Chen Lihui(email: lihui_chen@***) 1. The Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education China and School of Earth and Space Science Peking University 100871 Beijing China 2. Institute of Geology and Geophysics Chinese Academy of Sciences 100029 Beijing China

Ultramafic xenoliths are common in Tietonggou intrusion, Laiwu, Shandong Prov-ince. Peridotite xenoliths develop two-stage metasomatism popularly: (i) The early metasoma-tism is characterized by intergranular clinopyroxene and phlogopite; (ii) The later metasomatism is characterized by orthopyroxene veins with a few plagioclases and amphiboles. These ul-tramafic xenoliths are thought to be mostly from the crust-mantle transitional zone on the basis of their combination, mineral chemistry, equilibrium temperature, and metasomatic characteristics. Major elements, rare earth elements, and Sr-Nd isotopic composition of the ultramafic xenoliths indicate that there is a petrogenetic relationship between the silica-enriched xenoliths and their host diorites. We propose that such silica enrichment might be an indicator of melt-rock interac-tions in the Mesozoic lithosphere beneath western Shandong.

关键词： ultramafic xenoliths, crust-mantle transitional zone,metasomatism, Tietonggou intrusion, Laiwu.