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Episodes 2008年第4期31卷 401-407页

作者： steffen mischke Chengjun Zhang Institute of Geological Sciences Freie Universitat Berlin Malteserstr. 74-100 12249 Berlin Germany Lanzhou University Centre for Arid Environment and Paleoclimate Research Gansu 730000 China

A mid-Holocene tufa section at 3,815 m altitude in the Qilian Mountains at the northeastern margin of the Tibetan Plateau was tested as a possibly important new climate archive. The tufa carbonate displays a distinct alternation of white and dark layers most probably representing annually deposited sparry and microgranular calcite which is formed during the warm and relatively wet summer and the drier and cooler spring and autumn season with an interruption of tufa formation during the freezing period. The δ^18O record of the tufa site comprises probably 357 years of annually deposited car-bonate-about 4, 000 years bejCore present, which indicates the prevalence of wetter climatic con- ditions in comparison to the present-day situation. This inference is confirmed by palynological data and lake-level reconstructions from a number of sites in the northern foreland of the Qilian Mountains, highlighting the large potential of longer tufa sequences for high-resolution palaeoclimate studies in the future.

关键词：祁连山全新世中期片状石灰华碳酸盐

Carbon and Oxygen Isotopic Composition of Surface-Sediment Carbonate in Bosten Lake (Xinjiang,China) and its Controlling Factors

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Acta Geologica Sinica(English Edition) 2009年第2期83卷 386-395页

作者： steffen mischke Alexander PROKOPENKO Freie University Berlin BerlinGermany Department of Geological Sciences University of South CarolinaColumbiaSouth CarolinaUSA

Bosten Lake is a mid-latitude lake with water mainly supplied by melting ice and snow in the Tianshan Mountains. The depositional environment of the lake is spatially not uniform due to the proximity of the major inlet and the single outlet in the western part of the lake. The analytical results show that the carbon and oxygen isotopic composition of recent lake sediments is related to this specific lacustrine depositional environment and to the resulting carbonate mineralogy. In the southwestern lake region between the Kaidu River inlet and the Kongqi River outlet, carbon isotope composition （δ^13C） values of the carbonate sediment （-1‰ to -2‰） have no relation to the oxygen isotope composition of the carbonate （δ^18O） values （-7‰ to -8‰）, with both isotopes showing a low variability. The carbonate content is low （〈20%）. Carbonate minerals analyzed by X-ray diffraction are mainly composed of calcite, while aragonite was not recorded. The salinity of the lake water is low in the estuary region as a result of the Kaidu River inflow. In comparison, the carbon and oxygen isotope values are higher in the middle and eastern parts of the lake, with δ^13C values between approximately ＋0.5‰ and ＋3‰, and δ^18O values between -1‰ and -5‰. There is a moderate correlation between the stable oxygen and carbon isotopes, with a coefficient of correlation r of approximately 0.63. This implies that the lake water has a relatively short residence time. Carbonate minerals constitute calcite and aragonite in the middle and eastern region of the lake. Aragonite and Mg-calcite are formed at higher lake water salinity and temperatures, and larger evaporation effects. More saline lake water in the middle and eastern region of the lake and the enhanced isotopic equilibrium between water and atmospheric CO2 cause the correlating carbon and oxygen isotope values determined for aragonite and Mg-calcite. Evaporation and biological processes are the main reasons for the salinity and carbonate mi

关键词： carbonate aragonite calcite stable carbon and oxygen isotope composition Bosten Lake

Carbon and Oxygen Isotopic Compositions: How Lacustrine Environmental Factors Respond in Northwestern and Northeastern China

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Acta Geologica Sinica(English Edition) 2013年第5期87卷 1344-1354页

作者： ZHANG Chengjun FAN Rong LI Jun steffen mischke laise DEMBELE HU Xiaolan School of Earth Sciences&Key Laboratory of Mineral Resources in Western China (Gansu Province) Lanzhou University College of Resource and Environmental Sciences Lanzhou University Institute of Earth and Environmental Science University of Potsdam

Surface lake sediments, 28 from Hoh XU, 24 from northeastern China, 99 from Lake Bosten, 31 from Ulungur and 26 from Heihai were collected to determine δ13C and δ18O values. Considering the impact factors, conductivity, alkalinity, pH, TOC, C/N and carbonate-content in the sediments, CI, P, S, and metal element ratios of Mg/Ca, Sr/Ca, Fe/Mn of bulk sediments as environmental variables enable evaluation of their influences on δ13C and δ18O using principal component analysis （PCA） method. The closure and residence time of lakes can influence the correlation between δ13C and δ18O. Lake water will change from fresh to brackish with increasing reduction and eutrophication effects. Mg/Ca in the bulk sediment indicates the characteristic of residence time, Sr/Ca and Fe/Mn infer the salinity of lakes. Carbonate formation processes and types can influence the 6~3C--~1So correlation. ~180 will be heavier from Mg-calcite and aragonite formed in a high-salinity water body than calcite formed in freshwater conditions. When carbonate content is less than 30%, there is no relationship with either 613C or 6180, and also none between δ13C and δ18O. More than 30%, carbonate content, however, co-varies highly to δ13C and δ18O, and there is also a high correlation between δ13C and δ18O. Vegetation conditions and primary productivity of lakes can influence the characteristics of δ13C and δ18O, and their co-variance. Total organic matter content （TOC） in the sediments is higher with more terrestrial and submerged plants infilling. In northeastern and northwestern China, when organic matter in the lake sediments comes from endogenous floating organisms and algae, the δ13C value is high. δ13C is in the range of-4‰ to 0‰ when organic matter comes mainly from floating organisms （C/N〈6）; in the range of-4‰ to 8‰ when organic matter comes from diatoms （C/N=6 to 8）; and -8‰ to -4‰ when organic matter comes from aquatic and terrestrial plants （C/N〉8）.

关键词： Limnology isotopic analysis carbonates organic matter PCA Tibet Xinjiang,Northeastern China

Weak Summer Monsoon during the Early Holocene Inferred from the Dingxi Lujiagou Floodplain Lake-Eolian Sand Rhythm due to Solar Impacting

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Acta Geologica Sinica(English Edition) 2019年第3期93卷 778-779页

作者： ZHANG Wanyi ZHANG Huirong MA Yuan WANG Xiaoyu steffen mischke ZHANG Chengjun College of Earth Sciences&Key Laboratory of Mineral Resources in Western China(Gansu Province) Lanzhou UniversityLanzhou 730000China College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China Faculty of Earth Sciences University of Iceland101 ReykjavikIceland

Objective Precipitation was the highest in the loess plateau during the Early Holocene 10-8 ka BP even to the period 10-3.0 ka BP in the Kesang cave stalagmite westward Tianshan,Xinjiang,based on large numbers of records from paleoclimatic proxies(An et al.,2000;Zhang et al.,2009;Zhang et al.,2018).However,we discovered at first time that floodplain lake-eolian stratigraphical rhythm complex kept in the Lujiagou of Dingxi,Gansu,which was important geological proof to indicate a weak summer monsoon transition period during the Early Holocene in the Chinese Loess Plateau.

关键词： Solar Impacting Weak Summer Monsoon

A large Middle Pleistocene freshwater to oligohaline lake in the contemporary hyperarid Qaidam Basin （China）

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Episodes 2006年第1期29卷 34-38页

作者： steffen mischke Ulrike Herzschuh Naida Sun Zizhen Qiao Zhencheng Sun Institute of Geological Sciences Freie Universitiit Berlin Malteserstr. 74-100 12249 Berlin Germany. Alfred Wegener Institute for Polar and Marine Research Research Unit Potsdam Telegrafenberg A43 14473 Potsdam Germany China University of Petroleum Department of Earth Science Beijing 102200 P.R. China Headquarter of Petroleum Exploration and Development of Qinghai Province CNPC Dunhuang 736202 P.R. China

The Qaidam Basin （NW China） at the northern margin of the Tibetan Plateau is one of the driest places on Earth with mean annual precipitation not exceeding 25 mm in the western central part. Flat salt plains and wind-shaped hills characterise the bare ground over thousands of square kilometres. In contrast to presentday conditions, remnants of ancient shorelines in high positions identified by Chen and Bowler （1986） and HiJvermann and Siissenberger （1986） about 20 years ago herald of a former large lake but were not investigated further till now. Here we present the results of microfossil analysis and optically stimulated luminescence （OSL） as well as uranium-series （TIMS） dating of sediments from a thick sequence of predominantly lake deposits in the eastern central Qaidam Basin. Based on abundant ostracod （micro-crustacean） shells from this sequence, we infer that a large lake of several metres depth at least maintained primarily fresh to oligohaline conditions in the late Middle Pleistocene.

关键词： CENTRAL-ASIA PLATEAU MAGNETOSTRATIGRAPHY PROTOCOL UPLIFT LOESS

Sub-Recent Sexual Populations of Limnocythere inopinata Recorded for the First Time from>3500 m Altitude on the Tibetan Plateau

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Acta Geologica Sinica(English Edition) 2015年第3期89卷 1041-1042页

作者： ZHANG Wanyi steffen mischke ZHANG Chengjun ZHANG Huirong WANG Peng School of Resources and Environmental Sciences Lanzhou University Institute of Earth and Environmental Science University of Potsdam Faculty of Earth Sciences University of Iceland School of Earth Sciences & Key Laboratory of Mineral Resources in Western China(Gansu Province) Lanzhou University

The central and northwestern Tibetan Plateau region,also called＂Qiangtang Plateau＂（30°27＇25＂-35°39＇13＂N,83o41＇14＂-95°10＇46＂E）,is the highest and largest arcticalpine area of the Earth covering approxima... 详细信息

关键词： Sub-Recent Sexual Populations of Limnocythere inopinata Recorded for the First Time from>3500 m Altitude on the Tibetan Plateau

High-Resolution Records of the Holocene Paleoenvironmental Variation Reflected by Carbonate and Its Isotopic Compositions in Bosten Lake and Response to Glacial Activities

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Acta Geologica Sinica(English Edition) 2009年第6期83卷 1101-1115页

作者： ZHANG Chengjun ZHENG Mianping Alexander PROKOPENKO steffen mischke GOU Xiaohui YANG Qili ZHANG Wanyi FENG Zhaodong School of Resources and Environmental Sciences Lanzhou University Lanzhou 730000 Gansu China Center of Saline Lake and Epithermal Deposit Chinese Academy of Geological Sciences Beijing 100037 China University of South Carolina Columbia SC 29205 USA Freie University Berlin Berlin 12249 Germany

The Early Holocene paleoclimate in Bosten Lake on the northern margin of the Tarim Basin, southern Xinjiang, is reconstructed through an analysis of a 953 cm long core （BSTC2000） taken from Bosten Lake. Multiple proxies of this core, including the mineral components of carbonate, carbonate content, stable isotopic compositions of carbonate, Ca/Sr, TOC and C/N and C/S of organic matter, are used to reconstruct the climatic change since 8500 a B.P. The chronology model is made by nine AMS 14C ages of leaves, seeds and organic matter contained in two parallel cores. The climate was cold and wet during 8500 to 8100 a B.P. Temperature increased from 8100 to 6400 a B.P., the climate was warm and humid, and the lake expanded. The lake level was highest during this stage. Then from 6400 to 5100 a B.P., the climate became cold and the lake level decreased slightly. During the late mid-Holocene, the climate was hot and dry from 5100 to 3100 a B.P., but there was a short cold period during 4400 to 3800 a B.P. At this temporal interval, a mass of ice and snow melting water supplied the lake at the early time and made the lake level rise. The second highest lake level stage occurred during 5200 to 3800 a B.P. The climate was cool and wet during 3100 to 2200 a B.P., when the lake expanded with decreasing evaporation. The lake had the last short-term high level during 3100 to 2800 a B.P. After this short high lake level period, the lake shrank because of the long-term lower temperature and reduced water supply. From 2200 to 1200 a B.P., the climate was hot and dry, and the lake shrank greatly. Although the temperature decreased somewhat from 1200 a B.P. to the present, the climate was warm and dry. The lake level began to rise a little again, but it did not reach the river bed altitude of the Konqi River, an outflow river of the Bosten Lake.

关键词： carbonate isotopic composition glacial activity paleoenvironmental variation Bosten Lake

河北泥河湾盆地油房北旧石器地点的发现与研究

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第四纪研究 2021年第1期41卷 164-177页

作者：赵海龙谭培阳孙雪峰 mischke steffen 河北师范大学历史文化学院河北石家庄050024 南京大学地理与海洋科学学院江苏南京210023 Faculty of Earth Sciences University of IcelandReykjavíkIceland

油房北旧石器地点是河北省泥河湾盆地东缘的一处考古新发现,本文对该地点的下部文化层相关情况做了重点介绍。下部文化层的厚度约2.5 m,在3 m2的试掘范围内出土了石制品、动物化石及自然砾石等标本计600余件。石器工业面貌整体上承袭了... 详细信息

油房北旧石器地点是河北省泥河湾盆地东缘的一处考古新发现,本文对该地点的下部文化层相关情况做了重点介绍。下部文化层的厚度约2.5 m,在3 m2的试掘范围内出土了石制品、动物化石及自然砾石等标本计600余件。石器工业面貌整体上承袭了我国华北地区的小石片石器文化传统。微体古生物化石(介形虫等)研究表明,该文化层自下而上经历了河流阶地到湿地环境的转变。光释光方法测得其年代大约在8.6~10.8万年,相当于深海氧同位素5阶段(MIS5),处于末次间冰期。油房北地点的考古发现增添了末次间冰期古人类活动的新证据,为研究当时古人类的生计方式及人地关系提供了重要实物资料。

关键词：泥河湾油房北地点末次间冰期旧石器时代中期

内蒙古萨拉乌苏河流域滴哨沟湾全新世早—中期湖相沉积的地球化学古气候响应

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海洋地质与第四纪地质 2013年第4期33卷 103-112页

作者：赵琦樊荣李保生 steffen mischke 张成君兰州大学资源环境学院环境科学与工程研究所华南师范大学地理科学学院 Institute of Earth and Environmental Science University of PotsdamPotsdam14476Germany 兰州大学地球科学与矿产资源学院

通过对毛乌素沙漠南缘萨拉乌苏河流域滴哨沟湾剖面沉积物粒度、有机碳含量(TOC)、碳酸盐含量、无机碳酸盐碳氧同位素组成等分析测试,在已有的大量年代测定数据基础上,重建了该地区末次冰期晚期到中全新世期间的古环境。分析表明,11 000... 详细信息

通过对毛乌素沙漠南缘萨拉乌苏河流域滴哨沟湾剖面沉积物粒度、有机碳含量(TOC)、碳酸盐含量、无机碳酸盐碳氧同位素组成等分析测试,在已有的大量年代测定数据基础上,重建了该地区末次冰期晚期到中全新世期间的古环境。分析表明,11 000～9 950aBP滴哨沟湾地区气候干凉,萨拉乌苏河受陕北高原降水和当地冰溶地下水补给;9 950～9 100aBP为全新世初温度、降雨增加时期,有效湿度较高,滴哨沟湾湖泊开始形成;9 100～5 850aBP气温继续上升,降雨增加,但相对湿度减小,该时期是滴哨沟湾湖泊发育最大时期,湖泊水体滞留时间较长;5 850～5 100aBP气温和降水开始下降,湖泊收缩;5 100～4 700aBP期间温度和降水继续下降,湖泊环境逐渐转变为沼泽环境;4 700～4 500aBP期间滴哨沟湾沙漠化,形成了古流动沙丘沙沉积,干旱化加强;而在4 500～4 380aBP时又一次短暂的温湿气候,在沙丘表层钙板隔水层之上形成了短暂的小规模积水;自4 380aBP之后,滴哨沟湾地区沙漠化,干旱状况持续到现在。

关键词：河湖相粉砂黑垆土地球化学环境指标全新世早中期滴哨沟湾

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青藏高原东北缘冬给错纳湖全新世湖面波动

第四纪研究 2019年第4期39卷 1018-1033页

作者：张菀漪张静雅 Nusrat Nazir Safarov Khomid 郑淇 mischke steffen 张成君兰州大学地质科学与矿产资源学院甘肃省西部矿产资源重点实验室甘肃兰州730000 冰岛大学地球科学学院冰岛雷克雅未克101

青藏高原处于东亚季风、印度季风和西风环流交互作用区.末次冰消期以来,太阳辐射对该地区的古气候环境产生了重要影响,湖泊随着季风系统的变化发生了明显的水位升降,对湖岸阶地的形成起到了直接作用.本项研究重建了青藏高原东北缘冬给... 详细信息

青藏高原处于东亚季风、印度季风和西风环流交互作用区.末次冰消期以来,太阳辐射对该地区的古气候环境产生了重要影响,湖泊随着季风系统的变化发生了明显的水位升降,对湖岸阶地的形成起到了直接作用.本项研究重建了青藏高原东北缘冬给错纳湖湖岸阶地记录的湖面波动历史,试图了解青藏高原季风系统演变过程.通过湖泊北岸265 cm厚湖岸阶地沉积物粒度、碳酸盐、矿物、元素和介形虫古环境指标,结合OSL年代模式,分析表明在约10. 2 ka B. P.之前水体较浅;约10. 2~9. 0 ka B. P.湖面开始上升,气候凉湿;9. 0~8. 5 ka B. P.为印度季风强盛期,湖面明显上升,降雨量增高、温度上升;8. 5~7. 9 ka B. P.湖面降低与气候变冷有关;7. 9~7. 0 ka B. P.印度季风开始减弱,气温、降雨下降,但有效湿度较大,湖面降低;7. 0~6. 1 ka B. P.湖面上升可能与低蒸发作用有关,印度季风仍然影响该地区;6. 1~5. 2 ka B. P.,印度季风衰退,气候逐渐变冷、降雨量减小、水体变浅;5. 2~4. 6 ka B. P.气候冷干,有效湿度减小,湖面进一步下降;4. 6 ka B. P.至今气候干冷,东亚季风衰退,湖面下降,期间也可能受西风环流影响而有短暂的降雨增加时期.

关键词：青藏高原冬给错纳湖全新世气候变化湖面波动