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Timing and geochemical characters of the Sanchazi magmatic arc in Mianlüe tectonic zone,South Qinling

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science china earth sciences 2004年第4期47卷 317-328页

作者： LI Shuguang1, HOU Zhenhui1, YANG Yongcheng2, SUN Weidong1,1), ZHANG Guowei3, & LI Qiuli1 1. School of earth and space sciences,university of {4. and technology of china ,hefei 2.002.,china 2. Regional Geological Survey Team of Shaanxi Province,Xianyang 712000, china 3. department of Geology, Northwest university,Xi抋n 710069, china Present address: Max-Planck-Institut f. Chemie Postfach 3060 55020 Mainz Germany School of earth and space sciences University of Science and Technology of China Hefei 230026 China Regional Geological Survey Team of Shaanxi Province Xianyang 712000 China department of Geology Northwest University Xi’an 710069 China

The Sanchazi mafic-ultramafic complex in Mianlüe tectonic zone,South Qinling can be subdivided into two blocks,*** paleo-magmatic arc and Zhuangkegou paleo-oceanic crust fragment (ophiolite).The Sanchazi paleo-magmatic arc is mainly composed of ande-site,basaltic and basalt-andesitic gabbro(or diorite),andesitic dyke,plagiogranite and minor ul-tramafric rocks,which have typical geochemical features of island arc volcanic rocks,such as high field strength element(***,Ti)depletions and lower Cr,Ni *** Light rare earth element (LREE) and K enrichments of these rocks and zircon xenocrystals of 900 Ma from plagiogranite suggest that this magmatic arc was developed on the South active continental margin of the South Qinling *** U-Pb age of (300±61) Ma for zircons from plagiogranite in-dicates that the Mianlüe paleo-oceanic crust was probably subducted underneath the South Qinling micro-continent in *** is consistent with the formation time (309Ma) of the Huwan eclogite originating form oceanic subduction in Dabie Mountains,suggesting that the Mianlüe paleo-ocean probably extended eastward to the Dabie Mountains in *** high-Mg adakitic rocks in Sanchazi paleo-magmatic arc suggest thet the subducted oceanic crust was relatively young (<25Ma) and hot.

关键词： Qinling orogen, magmatic arc, U-Pb zircon age, ophiolite complex.

GEOCHEMISTRY OF MAFIC-ULTRAMAFIC ROCKS FROM NORTHERN DABIE COMPLEXAND ITS IMPLICATION

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Scientia Geologica Sinica 1998年第4期 513-519页

作者： Chen Daogong Wu Yuanbao Cheng Hao Xia Qunke and Zhi Xiachen(department of earth and space sciences, {4. of science and technology of china, hefei, 2.002.)

Twelve samples ofJiaoziyan gabbroic rocks and four Zhujiapu pyroxenites from Northern Dabie complexwere analysed for major, REE and trace elements. Major elements of gabbroic rocks show fractionalcrystallization during its magma evolution. The LREE-enriched and HFSE- depleted characters of gabbrosand pyroxenites, together with their Nd and Sr isotopes indicate the involvement of terrestrial material inmantle source, probably related to its subduction. The chemical and isotopic signals for gabbros andpyroxenites aren't correlated to oceanic ophiolitic melange, but reflect their affinity of transition fromactive continental margin to island arc magmatism.

关键词： ITS Rb Ba GEOCHEMISTRY OF MAFIC-ULTRAMAFIC ROCKS FROM NORTHERN DABIE COMPLEXAND ITS IMPLICATION Zr Arc

A STORABE PROCESS OF THE MAGNETICENERGY RESULTS FROM THE UNSTEADY PLASMA FLOW FIELD IN THE DISTURBANCE REGIONS OF COMETARY TAIL AND ATMOSPHERE

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紫金山天文台台刊 1998年第2期 97-100页

作者： Li Zhong-yuan Shi Zhi-dong Chen Yao(department of earth and space science, {4. of Sciece and technology of china, Anhui, hefei, 2.002. P.R.C (Advanced Centre for Sciece and Astronomy, Third World Academy of sciences.)

In this paper we discuss coupling processes between a magnetic field and an unsteady plasma motion, and analyze the features of energy storage and conversions in the cometary disturbance regions.

关键词： Comet Disturbance in comet Energy conversions and evolution space plasma pro-cess

Rb－Sr ISOTOPE DATING ON FENITES FROM BAYANOBO，INNERMONGOLIA，chinaAND THEIR GEOLOGICALIMPLICATIONS

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Scientia Geologica Sinica 1994年第4期 457-467页

作者： Yang Xueming(department of earth and space sciences,{4. university of science and technology, hefei 2.002.) Zhang Peishan Tao Kejie Zhang Rengu(Institute of Geology, Chinese Academy of sciences Beijing 100029)Yang Xiaoyong(department of earth and Spa

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关键词： Rb INNERMONGOLIA chinaAND THEIR GEOLOGICALIMPLICATIONS Sr ISOTOPE DATING ON FENITES FROM BAYANOBO

The Effect of Heterogeneity on Rock's Ultrasonic Attenuation and Its Correction

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earthquake Research in china 2001年第3期15卷 222-229页

作者： Wang Baoshan, Sun Daoyuan,Li Shengjie, Li Weidong, Shi Xingjue, and Liu Bin department of earth and space science, {4. of science and technology of china, hefei 2.002., china department of earth and space science University of Science and Technology of China Hefei 230026 China

The effect of Rayleigh scatter caused by the heterogeneity of rocks, on attenuation measurement has been considered adequately. According to the related theory and calculation, we can distinguish the intrinsic attenuation from the scattering attenuation. And we amended the classic spectral ratio method, based on the homogeneous medium hypothesis. Using the improved spectral ratio method, we can obtain Q value within a wider frequency range, so we can eliminate the uncertainty condition in classic spectral ratio, where Q value depends on the frequency range. The frequency shift method has been introduced and improved. Those three methods on one set of data had been applied. The results obtained by using the classic and improved spectral ratio and frequency shift methods fit well.

关键词： Scatter Ultrasonic attenuation Q value Frequency shift Spectral ratio

高频条件下砂岩波速与多孔隙介质流体含量关系的研究

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石油地球物理勘探 1998年第3期33卷 355-362页

作者：蒋立新施行觉中国科学技术大学地球与空间科学系

在测量大庆油田砂岩样品纵横波速度与饱和度的变化关系中发现，在高频条件下，样品中的流体含量对横波速度基本上没有影响，而对纵波速度影响较大，并且在某一饱和度时出现波速最低值。文中引用并改进了三相介质气体包裹体模型，对上述... 详细信息

在测量大庆油田砂岩样品纵横波速度与饱和度的变化关系中发现，在高频条件下，样品中的流体含量对横波速度基本上没有影响，而对纵波速度影响较大，并且在某一饱和度时出现波速最低值。文中引用并改进了三相介质气体包裹体模型，对上述变化规律进行了探讨，认为孔隙中流体分布的均匀性和波的频率都对波速随饱和度变化曲线有影响。数值模拟与实验的结果较为一致。

关键词：砂岩孔隙介质流体分布高频条件油气勘探

Effect of isotope diffusion in solids on isochron ages under -pper mantle conditions

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Chinese science Bulletin 1997年第6期42卷 492-495页

作者： ZHI Xiachen, CHEN Zengbing, ZHANG Xuehua and ZHENG Yongfei1. department of earth and space sciences, {4. of science and technology of china, hefei 2.002., china: 2 Advanced Centre for earth science and Astronomy, USTC, Third World Academy of science, hefei 2.002., china

DODSON presented the concepts of closure temperature (T_c), transitional temperature range (T_h—T_l) and T_lT_l, the effect of matter transfer by diffusion on radiometric dating is not negligible in the transitional ... 详细信息

DODSON presented the concepts of closure temperature (T_c), transitional temperature range (T_h—T_l) and T_learth crust, geochronometers work usually under cooling conditions of Tearth mantle at T>T_l, the effect of matter transfer by diffusion on radiometric dating is not negligible in the transitional temperature range

关键词： diffusion in solids temperature transitional range isochron age lithospheric mantle.

Metallogenic geochemistry of Sb-mineralization in southern margin of North china platform

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Chinese science Bulletin 1999年第S2期44卷 17-18页

作者： YANG Xiaoyong~1, YANG Xueming~1, ZHANG Jianjun~2, CAO Gaoshe~2 and ZHANG Zhengwei~2 1. department of earth and space sciences, {4. of science and Technlogy of china, hefei 2.002., china 2. Institute of Geology, Henan Bureau of Geology and Mineral Resources, Zhengzhou 4.0053, china department of earth and space sciences University of Science and Technology of China Hefei 230026 China Institute of Geology Henan Bureau of Geology and Mineral Resources Zhengzhou 450053 China

1 Geological setting THE Sb mineralization zone in the south margin of North china platform is located in the transitional edgeof North china plate and Yangtze plate, belonging to Qinling fold system, whose tectonic line is inNWW-SEE direction regionally. Because of the huge compression caused by the collision of the twoplates, the rocks undergone strong deformation and metamorphism have very complicated structures. Theregional deep fault-Shuanghuaishu fault-controls Sb-mineralization zone belt, and all the Sb-oredeposits or mineralized spots appear alone at the very southern margin of the fault. The lithostragraphirunits in the mineralized zone are relatively simple, mainly composed of Jiebei Group （Pt2J2） of QinglingFormation （with middle-high metamorphsim） and the upper Triassic system （with little metamorphism）.

关键词： Sb-mineralization metallognic geochemistry North china plateform.

Measurement of Attenuation Q Value of Cylindrical Sample from Wave Energy

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earthquake Research in china 2000年第2期14卷 16-22页

作者： Shi Xingjue, Ye Lin, Zhao Cuiping, Li Guangquan and Li Weidongdepartment of earth and space sciences, {4. of science and technology of china,Advanced Center for earth science and Astronomy, Third World Academy of science, hefei 2.002., china department of earth and space sciences University of Science and Technology of ChinaAdvanced Center for Earth Science and AstronomyThird World Academy of ScienceHefei 230026China

Two methods for measuring the attenuation Q value,frequency-amplitude ratio method andwaveform inversion method,were *** size and shape of most rock samples in thelaboratory can hardly fulfill the rigorous requirements of the above methods.A new testmethod of using the wave energy to calculate the Q value was *** principle,calculation formulae and some points for attention were expounded;the relationship betweenQ_P and Q_E was discussed;and many samples were measured by this *** result wascompared with those by other methods,and it was considered that the Q value by this methodlies between Q_P and Q_E·

关键词： Attenuation Ultrasonic wave Energy