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Helium isotope investigation on magnetic reversal boundaries of loess-paleosol sequence at Luochuan, central Chinese Loess Plateau

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Chinese Science Bulletin 2007年第17期52卷 2407-2412页

作者： DU XueQing1,6, WANG YongHong2. REN JianGuo3. YE XianRen4 & LU HuaYu5,1 1 State Key Laboratory of Loess and Quaternary geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075,{2. 2.College of Marine geosciences, Ocean {3. of{2., Qingdao 2.6003.{2. 3.National Natural Science Foundation of{2., beijing 100085,{2. 4 Lanzhou Research Center for Petroleum and Natural Gas Resources, Institute of geology and geophysics, Chinese Academy of Sciences, Lanzhou 73.000,{2. 5 Key Laboratory of Coast and Island Development, school of geographic and Oceanographic Sciences, Nanjing {3., Nanjing 2.0093.{2. 6 Graduate {3. of Chinese Academy of Sciences, beijing 100049,{2. State Key Laboratory of Loess and Quaternary geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate university of Chinese Academy of Sciences Beijing China College of Marine geosciences Ocean University of China Qingdao China National Natural Science Foundation of china Beijing China Lanzhou Research Center for Petroleum and Natural Gas Resources Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou China Key Laboratory of Coast and Island Development School of Geographic and Oceanographic Sciences Nanjing University Nanjing China

Extraterrestrial particles have higher 3.e/4He ratios than those of terrestrial sediments ( > 100 Ra versus < 0.03.Ra, where Ra is the 3.e/4He ratio normalized to the atmospheric value of 1.4×10?6). The inter- planet... 详细信息

Extraterrestrial particles have higher 3.e/4He ratios than those of terrestrial sediments ( > 100 Ra versus 3.Ra, where Ra is the 3.e/4He ratio normalized to the atmospheric value of 1.4×10?6). The inter- planetary dust particles (IDPs), which are very rich in 3.e, continuously bombard the Earth and can accumulate in deposits. IDPs sedimentation rate changes can significantly influence 3.e concentration in the Earth surface sediments. Since IDPs are not easy to detect in terrestrial deposits, measuring helium isotopes is a helpful approach to examine changes in IDPs. Helium concentration and helium isotopic composition magnetic substances and the quartz particles were examined for helium concen- tration and helium isotopic ratio. Results show that the 3.e/4He ratio and the 3.e concentrations of the magnetic substances are clearly higher than those of the bulk samples and the quartz particles, and, the 3.e/4He ratio of the extracted magnetic substances is also higher than that of the average level of the Earth’s crust. The higher helium content in the magnetic fractions can be explained by an influx of IDPs.

关键词：中国黄土高原古土壤氦同位素行星际尘埃颗粒反方向磁化

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Megaripples from the Mesoproterozoic of the Kimberley region,northwestern Australia and its geological implications

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Journal of Palaeogeography 2012年第1期1卷 15-25页

作者： Lan Zhongwu 1,2.3.,Zhong-Qiang Chen 2.4,1.State Key Laboratory of Lithospheric Evolution,Institute of geology and {2.,Chinese Academy of Sciences,beijing 10002.,{3. 2.school of Earth and Environment,The university of Western Australia,Australia 3.Key Lab of Petroleum Resources Research,Institute of geology and {2.,Chinese Academy of Sciences,beijing 10002.,{3. 4.State Key Laboratory of Biogeology and Environmental geology,{3. university of geosciences (Wuhan),Wuhan 43.074,{3. State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China school of Earth and Environment The University of Western Australia Australia Key Lab of Petroleum Resources Research Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China State Key Laboratory of Biogeology and Environmental geology China University of Geosciences (Wuhan) Wuhan 430074 China

Large ripples are described from the Mesoproterozoic Hilfordy Formation in the Kimberley region,northwestern *** ripple index (RI) and ripple symmetry index (RSI) suggest the Kimberley ripples were likely generated by storm *** wave height is up to 15 2.0}cm and wave length is up to 70 90 *** features,incorporated with other morphological characteristics such as symmetry,steepness,ripple spacing,and compositions,agree well with the megaripples previously reported from the intertidal-nearshore settings of modern seas and the geological *** Mesoproterozoic ripples were likely generated by the storm-induced *** survey of the global record of megaripples reveals that such structures have occurred through the geological past from the Archean to present *** were particularly common in the Neoproterozoic and had the largest ripple length and ripple height among the modern and geological *** is probably because extreme storms prevailed at that *** frequent occurrence in present day beach is probably due to the prevalence of extreme storms caused by the monsoon or tsunami/earthquake influenced climatic regimes.

关键词： megaripples palaeohydrodynamics extreme storms Mesoproterozoic Hilfordy Formation Kimberley northwestern Australia

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Suggestion of a dynamic model of North china basin-range system

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Progress in Natural Science:Materials International 2003年第4期 73-82页

作者： SHAO Ji'an, ZHANG Changhou, ZHANG Luqiao, and ZHANG Yongbei (1. school of Earth and Space Sciences, Peking university, {2. 100871,{3. 2.{3. university of geosciences, {2. 100873.{3. 3. Inner-Mongolia Institute of geology, Hohhot 01002.,{3. 4. Institute of geology and geophysics, Chinese A-cademy of Sciences, {2. 10002.,{3.) school of Earth and Space Sciences Peking University Beijing 100871 China china university of {2.sciences Beijing 100873 China Inner-Mongolia Institute of geology Hohhot 010020 China Institute of geology and geophysics Chinese Academy of Sciences Beijing 100029 China

It is found from preliminary studies that previous basin-range models have difficulties in explaining the formation of theMesozoic North-china basin-range system. This work suggests a new model-" tectonic thermal erosion" model, which considers the North china basin of Late Mesozoic and its peripheral ranges as a unified system, identifies relationship between upwelling and lateral spreading of the asthenolith with horizontal rnovement and deformation of the upper crust in the system, clarifies the effects of underplat-ing erosion on the crustal evolution, and tries to establish an earth-dynamic modei of the North china Mesozoic basin-range supported by numerical simulation.

关键词： North china Mesozoic-Cenozoic basin-range system.

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Mesozoic basin evolution and tectonic mechanism in Yanshan, china

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Science china Earth Sciences 2004年第Z2期47卷 24-38页

作者： LIU Shaofeng1,2. LI Zhong3.& ZHANG Jinfang4 1. Key Laboratory of Lithospheric Tectonics, Deep-Level Process and Explovation, Ministry of Education of P. R. china,{2., china 2. {3. of geosciences and Resources, china university of geosciences,{2., china 3. Institute of geology and geophysics, Chinese Academy of Sciences, beijing 10002., china 4. Institute of Software, Chinese Academy of Science, beijing 100080, china Key Laboratory of Lithospheric Tectonics Deep-Level Process and Explovation Ministry of Education of P.R.ChinaBeijing 100083 China school of geosciences and Resources China University of Geosciences Beijing 100083 China Institute of geology and geophysics Chinese Academy of Sciences Beijing 100029 China Institute of Software Chinese Academy of Science Beijing 100080 China

The Mesozoic basins in Yanshan, china underwent several important tectonic transformations, including changes from a pre-Late Triassic marginal cratonic basin to a Late Triassic-Late Jurassic flexural basin and then to a late Late Jurassic-Early Cretaceous rift basin. In response to two violent intraplate deformation at Late Triassic and Late Jurassic, coarse fluvial depositional systems in Xingshikou and Tuchengzi Formations were deposited in front of thrust belts. Controlled by transform and extension faulting, fan deltas and lacustrine systems were deposited in Early Cretaceous basins. The composition of clastic debris in Late Triassic and Late Jurassic flexural basins respectively represents unroofing processes from Proterozoic to Archean and from early deposited, overlying pyroclastic rocks to basement rocks in provenance areas. Restored protobasins were gradually migrated toward nearly NEE to EW-trending from Early Jurassic to early Late Jurassic. The Early Cretaceous basins with a NNE-trending crossed over early-formed basins. The Early-Late Jurassic and Early Cretaceous basins were respectively controlled by different tectonic mechanisms.

关键词： Yanshan, Mesozoic, depositional provenance of basin, unroofing of provenance, basin evolution, tectonic mechanism.

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Tectonic evolution of the Dabieshan orogen: In the view from polyphase deformation of the Beihuaiyang metamorphic zone

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Science china Earth Sciences 2005年第7期48卷 886-899页

作者： LIN Wei1, 2. Faure Michel3. WANG Qingchen1 & Arnaud Nicolas4 1. LTE, Institute of geology and {2., Chinese Academy of Sciences, beijing 10002.,{3. 2. Department of Earth and Planetary Sciences, Graduate school of Science, Nagoya university, Japan 3. ISTO, UMR CNRS 6113. Batiment Géosciences, Orléans Université d’Orléans, 45067 Orléans Cedex 2. France 4. UMR 652. "Magmas et Volcans", 5 Rue Kessler, 63.00 Clermont-Ferrand, France LTE Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Department of Earth and Planetary Sciences Graduate School of Science Nagoya University Japan ISTO UMR CNRS 6113 Orléans Université d'Orléans 45067 Orléans Cedex 2 France UMR 652. Magmas et Volcans 63000 Clermont-Ferrand 5 Rue Kessler France

The Beihuaiyang metamorphic zone was formed by the Early Mesozoic collision of the North and South china Blocks. It consisted of the Foziling and Luzhenguan complexes and was thought to have never afforded a deep subduction. A similar feature of the deformation in the Dabieshan UHP metamorphic rocks implies that these different tectonic units share the same geodynamic background. The early stage of deformation can be preserved on account of their relatively shallower subduction than that for UHP rocks. On the basis of an analysis of the geo- logical structure and geochronological results, five deformational stages have been recognized: a D1-Early compressional deformation which represents the continental subduction; a D2.Early exhumation deformation producing a syn-convergence exhumation; a D3.Main deformation, represented by an exhumation deformation with Late Triassic age; a D4-Doming and its margin extensional gravity collapse deformation and finally a D5-regional extensional deformation of Cretaceous that was mostly introduced by the migmatization and plutonism.

关键词： Beihuaiyang metamorphic zone geometry kinematic polyphase deformation tectonic evolution.

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金沙江奔子栏-达日河段大型泥石流堆积扇的成因机制

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山地学报 2011年第3期29卷 312-319页

作者：陈剑崔之久戴福初许冲中国地质大学(北京)工程技术学院北京大学城市与环境学系中国科学院地质与地球物理研究所青藏高原研究室

金沙江上游奔子栏-达日河段属横断山区的干热河谷地带,河谷沿岸大型古泥石流堆积扇广泛发育,其成因却一直没有得到很好的研究。对该区瓦卡大型古泥石流堆积物进行了沉积结构、粒度、地球化学和孢粉等分析,揭示了泥石流的沉积环境及其形... 详细信息

金沙江上游奔子栏-达日河段属横断山区的干热河谷地带,河谷沿岸大型古泥石流堆积扇广泛发育,其成因却一直没有得到很好的研究。对该区瓦卡大型古泥石流堆积物进行了沉积结构、粒度、地球化学和孢粉等分析,揭示了泥石流的沉积环境及其形成过程。通过粗颗粒石英的光释光单片再生法(SAR)测年研究,获得金沙江上游奔子栏-达日河段古泥石流大规模暴发的年代为12.600~4 500 a BP。丰富的风化碎屑物源、陡峻的地形及雨季降水集中是该区古泥石流形成的主要原因。全新世早期青藏高原东南缘受西南季风加强的影响,气候趋于暖湿,季节性暴雨增加。金沙江上游干热河谷区大型泥石流堆积扇的发育年代暗示其是全新世早期西南季风加强作用下的地貌响应。从地质灾害防治的角度,由于现代气候因素导致泥石流灾害的频度和规模较小,预防该区地质灾害的重点应是防止人工砍伐树木和不合理的人工切坡导致对地表环境的破坏加剧。

关键词：金沙江干热河谷泥石流堆积扇气候变化

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Ce Anomalies of the Yangtze Region,South china,through the Ordovician and Silurian Transition

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Journal of Earth Science 2009年第6期20卷 941-948页

作者：严德天张丽琴李双建 Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education China University of GeosciencesWuhan Institute of geology and geophysics Chinese Academy of Sciences school of geodesy and geomatics Wuhan University Key Laboratory of geospace Environment & geodesy of Ministry of Education Wuhan University Petroleum Exploration and Production Institute of SINOPEC

Systematic Ce anomalies for whole-rock have been obtained from the shale-dominated, continuous, and pelagic sedimentary sequences spanning the Ordovician/Silurian （O/S） boundary at the Tieshui （铁水） of Xiushan （秀山）, Chongqing （重庆）, South china. Ce anomalies across the O/S boundary are recognized in three intervals, Wufeng （五峰）, Guanyinqiao （观音桥） and Longmaxi （龙马溪）. The calculated Ce/Ce＊ values of Wufeng Formation range from 0.84 to 0.96 （avg. 0.90）. In the Guanyinqiao Formation, the values of calculated Ce/Ce＊ range from 0.73.to 0.85 （avg. 0.79）. The Ce/Ce＊ values of uppermost Longmaxi Formation range from 0.87 to 0.96 （avg. 0.91）. All along the section, the magnitude of the Ce anomaly is always negative, but is more significant in the Guanyinqiao Formation. The relatively higher Ce/Ce＊ values in the Wufeng and Longmaxi shales are likely to be due to the sediments deposited under rather reducing conditions. The Ce anomaly apparently does play some regular roles in the anoxic events that accompany prominent mass extinctions, and this work provides new data of critical importance for constraining models on the end-Ordovician anoxic events and mass extinctions.

关键词： Ce anomaly redox mass extinction Ordovician/Silurian boundary Yangtze platform.

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Determination of Soil Radon Emanation using Gamma-ray Spectrometry Method

Determination of Soil Radon Emanation using Gamma-ray Spectr...

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The Second Asian and Oceanic Congress for Radiation Protection

作者： Wenke MEI Nanping WANG* school of geophysics and Information Technology {2. {3. of geosciences(beijing)and geo-detection Laboratory Ministry of Education of china 2. Xueyuan Road beijing 100083 {2.

The soil or bedrock beneath a building is one of the sources of radon gas in the indoor *** of the parameters that influence the soil radon concentration is the radon *** emanation from different types of material can be estimated to some extent if the content of 2.6Ra of a sample is *** gamma-ray spectrometry method for soil radon emanation measurement is proposed in this *** ameliorate current gamma-ray spectrometry method,in which the high activity uranium ore samples were analyzed with short counting time to measure radon daughters within a duration of a *** our method,we can diminish the statistic fluctuation error through prolonging the counting time for each *** kinds of soil with different textures collected in beijing and a serial of different water content samples have been measured for the research on the radon *** emanation of sample A which has larger radium content is more sensitive to water content in gamma-ray spectrometry *** sample’s water content changed from 0 to 13.8%,the emanation of sample A varied between（4.2.0.4）% and（2..4±2.0）%.The limit of this method has also been discussed.

关键词： radon emanation gamma-ray spectrometry water content

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超声实验中谱比法衰减的散射与本征吸收特性

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地球物理学报 2018年第3期61卷 1083-1094页

作者：周浩符力耘矿产地球化学国家重点实验室中国科学院地球化学研究所贵阳550002 中国科学院大学北京100049 中国石油大学(华东)地球科学与技术学院青岛266580

实际地球介质的弹性波衰减,无论是对于地球内部结构反演、含油气储层描述,还是对于地震岩石物理本身的基础研究而言,都十分重要.通过岩石物理实验测量岩石的弹性波衰减是相关研究的基本手段,而谱比法是一种最常用的测量方法.利用谱比法... 详细信息

实际地球介质的弹性波衰减,无论是对于地球内部结构反演、含油气储层描述,还是对于地震岩石物理本身的基础研究而言,都十分重要.通过岩石物理实验测量岩石的弹性波衰减是相关研究的基本手段,而谱比法是一种最常用的测量方法.利用谱比法测量的弹性波衰减,简称谱比法衰减,由介质的本征吸收特性和非均质散射特性共同决定.然而,在谱比法理论中,没有将这两种衰减特性的作用区分对待.因此,实验室测量的谱比法衰减中是否含有散射特性,其散射特性是否可以忽略,常不明确.本文基于对岩石物理实验中样品波形特征的基本认识,通过能流理论描述了弹性波的本征吸收和非均质散射过程,以及对应的尾波形成机理.文章还应用能流理论测量岩石的弹性波衰减,即能流法衰减.无论是通过理论推导,还是通过实验验证,谱比法衰减与能流法衰减都显示出良好的一致性.这两种直达波衰减的一致性暗示了谱比法衰减中存在着两种衰减特性.文中还对比分析了谱比法衰减与喷射流本征衰减的实验结果,该结果同样展示了谱比法衰减中可能存在着散射特性.因此,通过能流理论,可以利用样品波形的尾波特征定性判断谱比法衰减中可能存在的散射特性.即异常明显的尾波振幅可能意味着强烈的直达波非均质散射,谱比法衰减中的散射特性因而不可忽略.

关键词：谱比法散射衰减本征衰减尾波

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geomagnetic anomalies recorded in L9 of the Songjiadian loess section in southeastern Chinese Loess Plateau

Geomagnetic anomalies recorded in L9 of the Songjiadian loes...

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中国科学院地质与地球物理研究所第十届(2.10年度)学术年会

作者： WANG DaoJing~(1*),WANG YongCheng~2.HAN JingTai~1,DUAN MuGang~3.SHAN JiaZeng~1 & LIU TungSheng~1 1 Key Laboratory ofCenozoic geology and Environment,Institute of geology and geophysics,Chinese Academy of Sciences,{3. 10002.,china 2.6} university ofgeosciences,{3. 100083,china 3.school of Information Science and Technology,{3. Institute of Technology,{3. 100081,china

Detailed magnetostratigraphic and rock magnetic investigations on L8-S12.of the Songjiadian loess section in the Sanmenxia area, southernmost margin of the Chinese Loess Plateau were conducted in this ***/Brunhes(M/B) boundary occurred at the bottom of the loess unit *** top and bottom boundaries of the Jaramillo polarity subchron are found in the middle of L10 and the bottom of L12.*** fabric of the loess layers maintains the original depositional features and the recorded remanent magnetization analysis indicates little post-deposition disturbance *** late Matuyama chron,two anomalies of geomagnetic field have been detected in *** data demonstrated that these recorded anomalies were less likely a result of remagnetization,but more possibly the signature of geomagnetic excursions occurred,named SJD1 and *** is calculated that the midpoint ages of SJD1 and SJD2.are 0.917 Ma and 0.875 Ma,respectively,and the time-interval between the two events approximates 12.***,SJD1 is close to the Santa Rosa(0.92. Ma) and SJD2.corresponds to the Kamikatsura (0.886 Ma) *** consistence with previous studies,the geomagnetic field was weakened during these events.

关键词： Paleomagnetism polarity event loess Sanmenxia

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