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Response of grain size of Quaternary gravels to climate and tectonics in the northern Tibetan Plateau

Science China Earth Sciences 2007年第1期50卷 81-91页

作者： FU KaiDao FANG XiaoMin GAO JunPing han wenxia LI LiLi MOE National Laboratory of Western China’s Environmental Systems&College of Resource and Environment Lanzhou UniversityLanzhou 730000China Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100085China 不详

The widely distributed thick gravel deposits along the rim of the Tibetan Plateau have been long thought to be the product of rapid tectonic uplift of the plateau. However, this has been challenged by recent works that suggest these thick gravels may be the result of climate change. In this paper we carried out a detailed field measurement of gravel grain sizes from the Jiuquan and Gobi Gravel Beds in the top of the Laojunmiao section in the Jiuxi Basin in the northern margin of Qilian Mts. (northern Tibetan Plateau). The results suggest that the grain sizes of the Jiuquan and Gobi Gravel Beds over the last 0.8 Ma are characterized by nine coarse-fine cycles having strong 100-ka and 41-ka periodicities that correlate well with the loess-paleosol monsoon record and isotopic global climatic record from deep sea sediments as well as by a long trend of coarsening in gravel grain size. The coarse gravel layers were formed during the warm-humid interglaciations while the fine layers correspond to the cold-dry glaciations. Because the paleoclimate in NW China began to get dramatically drier after the mid-Pleistocene, we think the persistent coarsening of gravel grain size was most probably caused by the rapid uplift of the northern Tibetan Plateau, and that the orbital scale cyclic variations in gravel grain size were driven by orbital forcing factors that were superimposed on the tectonically-forced long-term coarsening trend in gravel size. These findings also shed new light on the interaction results of climate and tectonics in relation to the uplift of the Tibetan Plateau.

关键词： Tibetan Plateau Jiuxi Basin gravels grain sizes climate changes tectonics.

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An 8.1Ma calcite record of Asian summer monsoon evolution on the Chinese central Loess Plateau

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Science China Earth Sciences 2007年第3期50卷 392-403页

作者： CHEN XiuLing FANG XiaoMin AN ZhiSheng han wenxia WANG Xin BAI Yan HONG Ye Key Laboratory of Western China’s Environmental Systems(MOE)and College of Resources and Environment Lanzhou Univer-sityLanzhou 730000China Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100085China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710075China College of Atmospheric Science Lanzhou UniversityLanzhou 730000China

Carbonates in loess-red clay sequences consist mainly of calcite and dolomite. The EDTA analysis of carbonates in different size fractions and magnetic susceptibility reveal that calcite is a sensitive index of summer monsoon. The chemical analysis of carbonates and calcite from an 8.1 Ma loess-red clay sequence at Chaona on the Chinese central Loess Plateau shows that the evolution of the Asian summer monsoon experienced four stages, namely 8.1―5.5 Ma, 5.5―2.8 Ma, 2.8―1.5 Ma and 1.5―0 Ma, with increasing intensification and fluctuation, suggesting a possible combining impacts of uplift of the Tibetan Plateau and global changes on the Asian summer monsoon.

关键词： carbonates calcite evolution of Asian summer monsoon red clay-loess Chinese Loess Plateau

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Late Eocene pollen records and palaeoenvironmental changes in northern Tibetan Plateau

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Science China Earth Sciences 2008年第8期51卷 1089-1098页

作者： MIAO YunFa FANG XiaoMin SONG ZhiChen WU FuLi han wenxia DAI Shuang SONG ChunHui Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100085China National Laboratory of Western China Environmental Systerms of Education of China&Department of Geography Lanzhou UniversityLanzhou 730000China Nanjing Institute of Geology and Palaeontology Chinese Academy of SciencesNanjing 210008China

The Eocene palaeovegetation landscape and palaeoclimate reconstructed from the pollen records in the Jiuquan Basin, northwest China provide some important information on the early uplift of the Tibetan Plateau and the origin and evolution of the aridification in northwest China. The records show the arid-semiarid scrubs with open forest palynofloras controlled by the subtropical high existed in northwest China during the 40.2-33.4 Ma. Four pollen assemblages are found: Nitrariadites-Cheno-podipollis-Pinaceae assemblage (40.2-37.9 Ma) is followed by Chenopodipollis-Nitrariadites assemblage (37.9-34.6 Ma), Pinuspollenites & Abietineaepollenites-Chenopodipollis assemblage (34.6-33.9 Ma), and Chenopodipollis-Nitrariadites assemblage (33.9-33.4 Ma). The percentage of thermophilic types is in anti-correlation with that of the dry types, which means the palaeoclimate is relatively warmwet or cold-dry during most of that time. Such aridity may be related to the water vapor reduction and the planetary wind system movement northward in response to the cooling caused by small-ephemeral icesheets.

关键词： Tibetan Plateau pollen records Eocene planetary arid zone palaeoenvironment cooling

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Deep Drilling Campaign in the Western Qaidam Basin,NE Tibetan Plateau and their Revealed Global Temperature Forcing of Salt Formation in the Late Miocene-Quaternary

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 216-217页

作者： FANG Xiaomin LI Minghui Erwin APPEL WANG Jiuyi han wenxia ZhanG Weilin YANG Yibo CAI Maotang Key Laboratory of Continental Collision and Plateau Uplift & Institute of Tibetan Plateau Research Chinese Academy of Sciences Department of Geosciences University of Tübingen Key Laboratory of Salt Lake Resources and Chemistry & Qinghai Institute of Salt Lakes Chinese Academy of Sciences

The Qaidam Basin in the NE Tibetan Plateau has contributed the largest amount of potash in ***,how the potash was formed has long been a subject of *** we carried out a deep drilling

关键词： SG Deep Drilling Campaign in the Western Qaidam Basin,NE Tibetan Plateau and their Revealed Global Temperature Forcing of Salt Formation in the Late Miocene-Quaternary NE

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Intensified tectonic deformation and uplift of the Altyn Tagh range recorded by rock magnetism and growth strata studies of the western Qaidam Basin, NE Tibetan Plateau

Intensified tectonic deformation and uplift of the Altyn Tag...

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2015中国地球科学联合学术年会

作者： Tao Zhang wenxia han Xiaomin Fang Weilin Zhang Chunhui Song Maodu Yan Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau Research CAS Key Laboratory of Salt Lake Resources and Chemistry Qinghai Institute of Salt Lakes Chinese Academy of Sciences CAS Center for Excellence in Tibetan Plateau Earth Sciences School of Earth Sciences & Key Laboratory of Western China’s Mineral Resources of Gansu Province

The Altyn Tagh range is the tectonically and geographically northern edge of the Tibetan Plateau,precise dating of its activities is essential for understanding the possible mechanisms of the Tibetan Plateau uplift and its effects on climate *** the framework of basin-mountain coupling,both magnetic susceptibility and rock magnetic research were carried out on the Late Cenozoic sediments of the Honggouzi section（7-5 Ma）in the western Qaidam *** study attempts to find out the evolution history of tectonic and climatic changes and to detect their interactions in the Altyn Tagh *** results showed that magnetic susceptibility records kept relatively low and stable values before0Ma,and rapidly increased since0 *** rock magnetic results revealed that paramagnetic minerals,maghemite and hematite have been dominated during the early periods（>10 Ma）in the Honggouzi section,and were replaced by magnetite and maghemite after that time.A detailed comparison of magnetic susceptibility records in the Honggouzi section with tectonic and climate records from the study areas and surrounding regions were also carried *** with sedimentary facies,lithology and angular unconformity in the sequence,as well as seismostratigraphy data,paleocurrent study,provenance and conceptual models analyses,we argue that the0 Ma shift in the HGZ section might be caused by the uplift of the Altyn Tagh range during that time.

关键词： Rock magnetism growth strata tectonic uplift Altyn Tagh range Qaidam Basin

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天体轨道参数调控柴达木盆地第四纪盐类资源形成的新模式

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地球学报 2024年第5期45卷 715-727页

作者：韩文霞方小敏张涛中国科学院青海盐湖研究所盐湖资源绿色高值利用重点实验室青海西宁810008 中国科学院青藏高原研究所青藏高原地球系统与资源环境重点实验室北京100101 兰州大学地质科学与矿产资源学院甘肃兰州730000

盐类资源的形成受沉积盆地、干旱气候和物源补给三个关键因素的控制,以往的研究主要关注构造、沉积环境和物源因素在成盐过程中的作用,而忽视了干旱和极端干旱气候这一关键因素及其与盆地盐层形成的耦合机制。本文以中德联合在柴达木盆... 详细信息

盐类资源的形成受沉积盆地、干旱气候和物源补给三个关键因素的控制,以往的研究主要关注构造、沉积环境和物源因素在成盐过程中的作用,而忽视了干旱和极端干旱气候这一关键因素及其与盆地盐层形成的耦合机制。本文以中德联合在柴达木盆地西部察汗斯拉图凹陷获取的科学深钻为例,运用磁学、元素和同位素地球化学等指标反演研究区的水文气候演化历史,并通过时间域、频率域以及系统动力学演化特征等综合分析手段探究了深时气候变化的控盐机制和规律。结果表明,柴达木盆地西部地区自2.7 Ma以来存在2.2~1.95 Ma、1.3~1.1 Ma、0.85~0.65 Ma和0.5~0.3 Ma四次关键的干旱化加剧和盐层发育期;发现在天体轨道倾角低幅和低偏心率值的同步期,会通过促进北半球冰盖扩张调控北半球中高纬西风环流的位置和强度,进而影响柴达木盆地的气候和水文循环,控制盆地内干旱事件的发生和盐层发育。在轨道-亚轨道-千年尺度上,全球冰量和北半球高纬气候变化也显著地控制了柴达木盆地的干旱事件和盐层发育。柴达木盆地多个凹陷区的盐层对比结果进一步表明,这一天体轨道特殊组合控制盆地的干旱事件和盐层发育过程的机制在全盆地具有普适性,促使柴达木盆地多个不同凹陷区尽管盐层发育存在一些差异,但其主要的盐层发育期均集中在上述四个关键时期。研究成果不仅为柴达木盆地乃至其他干旱区的成盐机制和深时发育规律提供了新的理论视角和研究思路,而且为未来结合构造-气候-物源耦合研究,对不同区域盐类资源发育类型和规律进行精细化研究,以及深入探索深时盐层发育规律提供了重要的研究基础。

关键词：柴达木盆地盐类资源偏心率与倾角北半球冰盖西风环流

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Paleogeography control of Indian monsoon intensification and expansion at 41 Ma

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Science Bulletin 2021年第22期66卷 2320-2328,M0004页

作者： Xiaomin Fang Maodu Yan Weilin Zhang Junsheng Nie wenxia han Fuli Wu Chunhui Song Tao Zhang Jinbo Zan Yongpeng Yang State Key Laboratory of Tibetan Plateau Earth System Resources and EnvironmentInstitute of Tibetan Plateau Research(TPESRE)Chinese Academy of SciencesBeijing 100101China Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Key Laboratory of Western China’s Environments of Ministry of Education Lanzhou UniversityLanzhou 730000China Shandong Provincial Key Laboratory of Water and Soil Conservation&Environmental Protection School of Resource and Environmental SciencesLinyi UniversityLinyi 276000China School of Earth Sciences&Key Laboratory of Western China’s Mineral Resources of Gansu Province Lanzhou UniversityLanzhou 730000China

As a crucial part of the Asian monsoon stretching from tropical India to temperate East Asia, the Indian monsoon(IM) contributes predominant precipitation over Asian continent. However, our understanding of IM’s onset, development and the underlying driving mechanisms is limited. Increasing evidence indicates that the IM began in the Eocene or even the Paleocene and was unexceptionally linked to the early rise of the Tibetan Plateau(TP). These were challenged by the heterogeneous and diachronous uplift of the TP and all the reported records were confined to tropical zone under tropical monsoon driven by the Intertropical Convergence Zone(ITCZ) that is irrelevant to the TP. Therefore, reliable paleoclimatic records from the extra-tropical IM region is crucial to reveal how the tropical IM expanded to subtropical and temperate zones and what driving factors might be related to it. Here we present robust Eocene paleoenvironmental records from central Yunnan(~26°N) in subtropical East Asia. The multiproxy results of two sites demonstrate a consistent sudden switch from a dry environment in the early Eocene to a seasonally wet one at 41 Ma, suggesting a jump of the tropical IM to the southern subtropical zone at 41 *** full collision of India with Asia, and the resulting changes in paleogeography at 41 Ma(closure of the Neotethys sea, retreat of the Paratethys seas, fast northward movement of the southern margin of the TP and rise of the central TP), aided by synchronous Antarctic cooling, might have worked together to drive the IM enhancement and northward expansion.

关键词： Asia paleogeography Indian tropical monsoon Eocene paleoenvironment Subtropical monsoon onset Driven factors and forcings

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塔里木盆地南缘8.5 ka以来的黄土岩石磁学特征及其磁化率变化机制

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地球物理学报 2019年第8期62卷 3053-3066页

作者：吕爽韩文霞张涛韩凤清卢胜城马学海张志高中国科学院青海盐湖研究所中国科学院盐湖资源综合高效利用重点实验室西宁810008 青海省盐湖地质与环境重点实验室西宁810008 中国科学院大学北京100049 山东省水土保持与环境保育重点实验室临沂大学资源环境学院山东临沂276005 中国科学院青藏高原研究所大陆碰撞与高原隆升重点实验室北京100101 安阳师范学院资源环境与旅游学院河南安阳455000

黄土岩石磁学参数是古气候研究中的重要指标,其中磁化率应用最为广泛,并在黄土高原地区取得重大进展,其受控于成壤作用的变化机制也被普遍接受.然而在黄土高原外缘的新疆地区,磁化率的变化机制仍不明确,导致磁化率的古气候意义在该区存... 详细信息

黄土岩石磁学参数是古气候研究中的重要指标,其中磁化率应用最为广泛,并在黄土高原地区取得重大进展,其受控于成壤作用的变化机制也被普遍接受.然而在黄土高原外缘的新疆地区,磁化率的变化机制仍不明确,导致磁化率的古气候意义在该区存在较大争议.本文选取塔里木盆地南缘具有精确年代控制的典型黄土剖面(羊场剖面)开展岩石磁学和高分辨率磁化率研究,利用交叉小波分析方法并结合剖面粒度、矿物及元素特征对该地区磁化率变化机制进行初步探讨.结果显示,羊场剖面的岩石磁学性质主要由粗颗粒软磁性矿物所控制,同时也表现出一定的顺磁性特征.根据载磁矿物和磁化率变化特征可将剖面进一步划分为两个阶段:阶段Ⅰ(8.5~2.5ka),载磁矿物以亚铁磁性的磁铁矿为主,磁化率值整体较高;阶段Ⅱ(2.5~0.2ka),亚铁磁性矿物依然占据主导地位,但硬磁性矿物和以黄铁矿为代表的顺磁性矿物相对增多,磁化率值显著降低.相关性研究和交叉小波分析表明:阶段Ⅰ磁化率与粗颗粒组分的变化具有一致性,符合“风速论”模式;阶段Ⅱ磁化率不仅与粗颗粒组分具有明显的正相关关系,而且与指示成壤作用强度的频率磁化率百分含量呈现出显著的负相关关系,暗示了阶段Ⅱ的磁化率变化可能受到“风速论”和“还原性成壤”模式的共同影响.本文拓宽了对新疆地区黄土岩石磁学特征及其磁化率变化机制的深入理解,也为利用磁化率恢复新疆及中亚地区全新世以来的古气候变化历史提供了新的线索.

关键词：塔里木盆地南缘黄土岩石磁学磁化率变化机制交叉小波分析

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