检索结果-南通市图书馆

Mercury deposition in central China from the Last Glacial Maximum to the early Holocene recorded in an accurately-dated stalagmite

引用

Science Bulletin 2025年第1期70卷 90-95页

作者： Yanzhen Li Liangcheng Tan Simin Jin Hai Xu Lüfan Chen David B.Kemp Ashish Sinha Le Ma Chunju Huang Lawrence R.Edwards Hai Cheng State key laboratory of Loess and quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China Xi’an Institute for Innovative Earth environment Research Xi’an 710061China State key laboratory of Biogeology and environmental Geology and Hubei key laboratory of Critical Zone evolution School of Earth SciencesChina University of GeosciencesWuhan 430074China Institute of Surface-Earth System Science Tianjin UniversityTianjin 300072China Department of Earth Science California State University Dominguez HillsCarson CA 90747USA Department of Earth and environmental Sciences University of MinnesotaMinneapolis MN 55455USA Institute of Global environmental Change Xi’an Jiaotong UniversityXi’an 710049China

Characterization of transport pathways and depositional changes in Mercury(Hg)and their connection to climatic and environmental changes on various time scales are crucial for better understanding the anthropogenic impacts on the global Hg cycle in the Anthropocene *** this study,we examined Hg variations recorded in a stalagmite from central China,covering the period from 25.5 to 10.9 thousand years *** data show a marked increase in Hg concentrations during the late Last Glacial Maximum,which coincided with the period of highest dust deposition on the Chinese Loess *** concentrations were lower during Heinrich events 1 and 2 and the Younger Dryas but higher during the BùllingAllerùd and the early *** suggest that regional dust load,which enhances atmospheric dry deposition of Hg,is the primary factor influencing Hg deposition in central China on glacialinterglacial *** millennial-to-centennial timescales,climate also plays a significant *** and wetter conditions increase vegetation,litterfall,and soil/rock weathering,which in turn boost mineral dissolution and soil erosion in the vadose *** processes collectively result in higher Hg concentrations in the stalagmite.

关键词： Speleothem Hg Glacial-interglacial cycle Millennial-to centennial-scale

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

New Phenotypes of Limnocythere inopinata from Lakes in Badain Jaran Desert,Northern China

引用

Acta Geologica Sinica(English Edition) 2021年第4期95卷 1411-1412页

作者： JIANG Gaolei ZHAI Dayou ZHAO Hua SHEN Jianmei NIE Zhenlong LIU Linjing MAO Xin WANG Zhe Institute of Hydrogeology and environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China key laboratory of quaternary chronology and environment evolution China Geological SurveyShijiazhuang 050061China Yunnan key laboratory for Palaeobiology Yunnan UniversityKunming 650091China

Objective Limnocythere inopinata(Baird,1843)is an ostracod widely distributed in recent non-marine waters and in quaternary sediments,where it comprises various phenotypes(Yin et al.,1999;Zhang et al.,2015).Based on the nodation patterns,five phenotypes were described in previous publications,namely,the unnoded,the phenotype with one node in the postero-ventral part of the valve,one with two nodes in the antero-ventral and postero-ventral parts of the valve,another with three nodes in the antero-ventral,postero-ventral and postero-dorsal parts of the valve.

关键词： Desert quaternary waters

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Discovery of quaternary Paleoflood Deposits on the Southern Margin of the Badain Jaran Desert,Northwestern China

引用

Acta Geologica Sinica(English Edition) 2021年第5期95卷 1784-1785页

作者： YANG Jinsong SHEN Jianmei NIE Zhenlong WANG Zhe LIU Zhe JIANG Gaolei Institute of Hydrogeology and environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China key laboratory of quaternary chronology and environment evolution China Geological SurveyShijiazhuang 050061China State key laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China

Objective The Badain Jaran Desert,located in western Inner Mongolia,is the second largest desert in China(Fig.1 a).It is well known for the coexistence of lakes and megadunes in the southeastern part of the desert(Fig... 详细信息

关键词： Desert quaternary flood

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Late Miocene–early Pleistocene paleoproductivity variations of the Lop Nor in the Tarim Basin and its implications on aridification in Asian Interior

引用

Chinese Science Bulletin 2014年第28期59卷 3650-3658页

作者： Hong Chang Zhisheng An Weiguo Liu Feng Wu Xiaoke Qiang Yougui Song State key laboratory of Loess and quaternary Geology Institute of Earth Environment Chinese Academy of Sciences

Extensive lacustrine deposits in the eastern Tarim Basin provide records of climate change influenced by the westerly winds and the Asian monsoon. To characterize the evolution of climate change in this region, we analyze elemental concentrations of barium(Ba) from the Ls2 drill core of Lop Nor, a paleo-lakebed located in the eastern Tarim Basin. Biogenic Ba concentrations from this drill core display a large-amplitude oscillation that generally follows a pattern similar to that of Artemisia content and ostracod assemblages, suggesting that is may serve as an index for climate change experienced in the basin. Our results indicate that biogenic Ba is especially sensitive to precipitation. All climatic proxies served in this study vary significantly over late Miocene to early Pleistocene time period. Strong aridification of eastern Tarim in the late Miocene to the early Pliocene may be attributed to a latitudinal shift in the westerly winds, which would have resulted in more moisture transported to southern and eastern Tibet. The growth of the Himalaya and Tibetan Plateau may have acted as an orographic barrier that blocked moisture sourced in the south from the northern margins of the plateau. We link weaker aridification in the late Pliocene to an increased intensity of the Indian Monsoon.

关键词：晚中新世早更新世亚洲季风塔里木河流域干旱化罗布泊古生产力塔里木盆地

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Geochronology of a surface core in the northern basin of Lake Qinghai: Evidence from ^(210)Pb and ^(137)Cs radionuclides

引用

Chinese Journal Of Geochemistry 2006年第4期25卷 301-306页

作者：徐海艾莉谭亮成安芷生 State key laboratory of Loess and quaternary Geology Institute of Earth Environment Chinese Academy of Sciences

The radioactivities of 210Pb and 137Cs have been measured to estimate the dates of the sediments of a surface core （QH0407-C-2） in the northern basin of Lake Qinghai. The sedimentation rate derived from 210Pb radioactivity correlates well with that inferred from （137）Cs radioactivity. The dates calculated from depth sedimentation rate （cm/a） are similar to those derived from mass accumulation rate （g·cm-2·a-1） between 0-5 cm, but are significantly different below 5 cm, which has been ascribed to the compaction of surface sediments during early diagenesis. The dates derived from mass accumulation rate are consistent with those calculated from the AMS 14C dating model. The precipitation-controlled indices based on the chronology data derived from mass accumulation rate are similar in trends to the precipitation reconstructed from tree rings in adjacent region, which further verifies the reliability of the geochronology data.

关键词：深度沉降率质量积累率青海湖表面核

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Holocene vegetation change in relation to fire and volcanic events in Jilin, Northeastern China

引用

Science China Earth Sciences 2015年第8期58卷 1404-1419页

作者： ZHAO HongLi LI XiaoQiang Valerie A.HALL State key laboratory of Loess and quaternary Geology Institute of Earth Environment Chinese Academy of Sciences laboratory of Vertebrate evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of Sciences School of Geography Archaeology and Palaeoecology Queen's University Belfast

Volatiles erupted from large-scale explosive volcanic activities have a significant impact on climate and environmental *** an important ecological factor,the occurrence of fire is affected by vegetation cover,and fire can feed back into both vegetation and climatic *** causes of fire events are diverse;and can include volcanic *** amount of charcoal in sediment sequences is related to the frequency and intensity of fire,and hence under good preservation conditions fire history can be reconstructed from fossil charcoal *** now,little research on the role of fire has been carried out in northeastern *** this study,through research on charcoal and tephra shards from Gushantun and Hanlongwan,Holocene vegetation change in relation to fire and volcanic events in Jilin,Northeastern China,was *** tephra shards are present in Gushantun it is associated with low level of both conifers and broadleaved trees,and is also associated with a pronounced charcoal *** suggests forest cover was greatly reduced from a fire caused by an eruption of the Tianchi *** also detected one tephra layer in Hanlongwan,which also has the almost same depth with low level forest pollen values and one charcoal *** was caused probably by an eruption of the Jinlongdingzi volcano.

关键词： Holocene vegetation change fire history tephra shards volcanic events Northeastern China

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Unraveling the mechanisms underlying lake expansion from 2001 to 2020 and its impact on the ecological environment in a typical alpine basin on the Tibetan Plateau

引用

China Geology 2023年第2期6卷 216-227页

作者： Chang-chang Fu Xiang-quan Li Xu Cheng Institute of Hydrogeology and environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China key laboratory of quaternary chronology and Hydrological environmental evolution China Geological SurveyShijiazhuang 050061China Airborne Survey and Remote Sensing Center of Nuclear Industry Shijiazhuang 050000China

Yanhu Lake basin(YHB)is a typical alpine lake on the northeastern Tibetan Plateau(TP).Its continuous expansion in recent years poses serious threats to downstream major *** a result,studies of the mechanisms underlying lake expansion are urgently *** elasticity method within the Budyko framework was used to calculate the water balance in the Yanhu Lake basin(YHB)and the neighboring Tuotuo River basin(TRB).Results show intensification of hydrological cycles and positive trends in the lake area,river runoff,precipitation,and potential *** expansion was significant between 2001 and 2020 and accelerated between 2015 and *** increase was the key factor underlying the hydrological changes,followed by glacier meltwater and *** overflow of Yanhu Lake was inevitable because it was connected to three other lakes and the water balance of all four lakes was *** high salinity lake water diverted downstream will greatly impact the water quality of the source area of the Yangtze River and the stability of the permafrost base of the traffic corridor.

关键词： Attribution analysis Budyko framework Climate change Lake expansion Water balance Diverting water to the Yangtze River Hydrogeology survey engineering Tibetan Plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Biogenic silica contents of Lake Qinghai sediments and its environmental significance

引用

Frontiers of Earth Science 2014年第4期8卷 573-581页

作者： Bin LIU Hai XU Jianghu LAN Enguo SHENG Shuai CHE Xinying ZHOU State key laboratory of Loess and quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China University of Chinese Academy of Sciences Beijing 100049 China laboratory of Human evolution and Archeological Science Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing 100044 China

Changes in the levels ofbiogenic silica （BSi%） in lake sediments have been widely used in order to study lake productivity and palaeoclimatic changes. However, the provenance of biogenic silica （BSi） needs to be investigated for each lake, especially for large lakes, as does the relationship between levels of BSi and relevant environmental factors. In this study, we measured the percentage of BSi contained in lake sediments, river sediments, and surface soils within the Lake Qinghai catchment, and compared the quantities and shapes of diatoms and phytoliths before and after the extraction processes. The results suggest that BSi in lake sediments is primarily derived from endogenous diatoms; therefore, BSi levels can be used to reflect the changes in primary productivity within the lake. Further comparisons showed that on long-term timescales, the variations in BSi% are generally consistent with those in total organic carbon （TOC） and grain size, reflecting the dominant impacts of precipitation on primary productivity in Lake Qinghai. On short-term timescales, however, the relationship between BSi% and TOC and that between BSi% and grain size are not clear or stable. For example, BSi% sometimes covaried with grain size, but it was sometimes out of phase with or even inversely related to grain size. We speculate that both climate and environmental processes, such as the dilution effect, influence short-term BSi% and its related environmental significance. As a result, BSi% should be used selectively as an indicator of climatic changes on different time scales.

关键词： biogenic silica environmental significance,Lake Qinghai precipitation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The vegetation and climate change during Neocene and Early quaternary in Jiuxi Basin, China

引用

Science China Earth Sciences 2005年第5期48卷 676-688页

作者： MA Yuzhen 1 , FANG Xiaomin 1,2 , LI Jijun 1 , WU Fuli 1 & ZHANG Jun 1 1. key laboratory of Western China’s environmental Systems and College of Resources and environment, Lanzhou University, Lanzhou 730000, China 2. State key laboratory of Loess and quaternary Geology, Institute of Earth environment, Chinese Academy of Sciences, Xi’an 710075, China 1. key laboratory of Western China’s environmental Systems and College of Resources and environment Lanzhou University 730000 Lanzhou China 2. State key laboratory of Loess and quaternary Geology Institute of Earth Environment Chinese Academy of Sciences 710075 Xi’an China

Sporopollen record in the Laojunmiao Section at Yumen in the Hexi Corridor foreland depression at the northern margin of the Tibetan Plateau revealed that during the period of 13.0―11.15 Ma the ecological environment of the Jiuxi Basin is characterized by steppe vegetation and a semi-moist climate. During 11.16―8.60 Ma prevailed forests of cypress and a still warmer, moister climate; steppe vegetation and dry climate began probably at about 8.6 Ma. Although aridification had been relaxed time and again during 8.40―6.93 Ma (forest-steppe, warm-semi-moist), 6.64―5.67 Ma (open-forest and steppe, warmer-semi-moist) and 5.42―4.96 Ma (steppe, semi-arid), the climate in the region became drier and drier in response to the fre- quent occurrence of aridity during 6.93―6.64 Ma (steppe, semi-arid), 5.67―5.42 Ma (de- sert-steppe, arid), 3.66―3.30 Ma (desert-steppe, arid) and 2.56―2.21 Ma (desert, arid). Perhaps the important findings of our study are the notable expansion of drought-enduring plants during 3.66―3.30 Ma and about 2.56 Ma and the replacement of vegetation by vast arid desert.

关键词： Tibetan Plateau Hexi Corridor sporopollen record ecological environment vegetation evolution aridific-ation.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chemical weathering profile in the V–Ti–Fe mine tailings pond:a basalt-weathering analog

引用

Acta Geochimica 2023年第6期42卷 1035-1050页

作者： Xiaolin Zhang Yinger Deng Liang Tang Zhengmeng Hou Jinsong Yang College of environment and Civil Engineering Chengdu University of TechnologyChengduChina Longchang Natural Resources and Planning Bureau Longchang 642150SichuanChina College of Earth Sciences Chengdu University of TechnologyChengdu 610059China Institute of Subsurface Energy Systems Clausthal University of Technology38678 Clausthal ZellerfeldGermany key laboratory of quaternary chronology and Hydro-environmental evolution Institute of Hydrogeology and Environmental GeologyChina Geological SurveyShijiazhuang 050061China

The(ultra-)mafic mine tailings pond revealed a weathering discrepancy in the tailings profile,which provided a valuable analog to assess the role of carbonate and silicate weathering of the *** this study,drill-cores samples were selected from the Wanniangou V–Ti–Fe mine tailings pond(Sichuan province,China)to investigate the mineralogicand geochemical characteristics in the tailings *** results reveal(1)the tailings pond profile consist of upper and lower *** upper layer is composed of carbonate weathering(1.4%),which was formed in the initial stages of tailings exposure and represented a minimal weathering degree.(2)The lower layer was primarily observed at the aquifer zone of the tailings pond,and was consistent with 0.45%carbonate weathering and 48.4%silicate weathering.(3)The weathering discrepancy in the tailings profile could be due to the sulfide oxidation and aerobic/flowing aquifer,which facilitate the water-tailings *** tailings profile provides an analog to studying basalt weathering,as it spans both carbonate and silicate *** research reinforces the idea that silicate weathering is predominant in basaltic areas and plays a crucial role in regulating atmospheric CO_(2)(carbon dioxide)levels on Earth.

关键词： V–Ti–Fe mine Tailings pond profile Drill core Basalt weathering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：