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Onset of Xiashu loess deposition in southern China by 0.9 Ma and its implications for regional aridification

Science China Earth Sciences 2018年第3期61卷 256-269页

作者： Xusheng LI Zhiyong HAN Huayu LU Yingyong CHEN Yang LI Xiaokang YUAN Yuwen ZHOU Mengyao JIANG Cunjuan LV School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210023 China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101 China College of Environment and Planning Henan University Kaifeng 475001

The Xiashu loess is a typical Quaternary eolian deposit in southem China and represents an important terrestrial paleoclimate archive in this low-latitude monsoon region. However, the chronological framework of Xiashu loess deposition has yet to be established. Determining the timing of the onset of Xiashu loess deposition will allow researchers to better understand late Quaternary aridification across the Asian continent, the evolution of the East Asian monsoon and regional environmental changes in subtropical regions. Therefore, in this study, a systematic chronological study of the Xiashu loess is conducted to answer this question. For the first time, magnetostratigraphic classification reveals that the Matuyama/Bnmhes （M/B） reversal is present in the Xiashu loess at two sites in Jiangsu Province, the Qingshan profile at Yizheng and the Dagang core in Zhenjiang. Based on the results of magnetostratigraphy and optically stimulated luminescence （OSL） dating, the age of the lower boundary of the Xiashu loess is estimated to be approximately 0.9 Ma. Consequently, this Xiashu loess deposit is the oldest reported to date and is comparable in age to the red soil deposit in Xuancheng, Anhui Province. The onset of Xiashu loess deposition by 0.9 Ma represents the further expansion of arid range in Asia in the late Quaternary in response to significant aridification and winter monsoon strengthening in this subtropical region. We suggest that these climate changes were primarily driven by global cooling and an increase in high-latitude ice volume in the Northern Hemisphere and that the initiation of Xiashu loess accumulation was a regional response of southern China to the 0.9 Ma global cooling event.

关键词： Xiashu loess chronology Magnetic stratigraphy Aridification East Asian monsoon

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Infl uence of altitude and tree class on climate-growth relationships in a larch plantation in subtropical China

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Journal of Forestry Research 2023年第6期34卷 1869-1880页

作者： Chunyan Wu Dongsheng Chen Xiaomei Sun Shougong Zhang State Key Laboratory of Tree Genetics and Breeding Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland AdministrationResearch Institute of ForestryChinese Academy of ForestryBeijing 100091People’s Republic of China

Precise quantifi cation of climate-growth relationships can make a major contribution to scientifi c forest ***,whether diff erences in the response of growth to climate at diff erent altitudes remains *** answer this,264 trees of Larix kaempferi from 88 plots,representing diff erent altitudinal ranges(1000-2100 m)and tree classes were sampled and used to develop tree-ring ***-ring growth(TRG)was either positively(dominant)or negatively(intermediate and suppressed)correlated with climate in diff erent tree classes at diff erent *** was strongly correlated with growing season at low altitudes,but was less sensitive to climate at middle *** was mainly limited by precipitation and was highly sensitive to climate at low ***-growth relationships at high altitudes were opposite compared to those at low *** of dominant trees was more sensitive to climate change compared to intermediate and suppressed *** factors(annual temperatures;moisture,the number of frost-free days)had diff erent eff ects on tree-ring growth of diff erent tree classes along altitudinal *** was concluded that the increase in summer temperatures decreased water availability,resulting in a signifi cant decline in growth rates after 2005 at lower *** is suitable for planting in middle altitudes and dominant trees were the best sampling choice for accurately assessing climate-growth relationships.

关键词： Tree-ring width index chronology Correlation coeffi cient Additive mixed models Tree classes

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Jurassic integrative stratigraphy and timescale of China

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Science China Earth Sciences 2019年第1期62卷 223-255页

作者： Diying HUANG State Key Laboratory of Palaeobiology and Stratigraphy Center for Excellence in Life and Paleoenvironment Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences

The Jurassic stratigraphy in China is dominated by continental sediments. Marine facies and marine-terrigenous facies sediment have developed locally in the Qinghai-Tibet area, southern South China, and northeast China. The division of terrestrial Jurassic strata has been argued, and the conclusions of biostratigraphy and isotope chronology have been *** the Jurassic period, the North China Plate, South China Plate, and Tarim Plate were spliced and formed the prototype of ancient China. The Yanshan Movement has had a profound influence on the eastern and northern regions of China and has formed an important regional unconformity. The Triassic-Jurassic boundary(201.3 Ma) is located roughly between the Haojiagou Formation and the Badaowan Formation in the Junggar Basin, and between the Xujiahe Formation and the Ziliujing Formation in the Sichuan Basin. The early Early Jurassic sediments generally were lacking in the eastern and central regions north of the ancient Dabie Mountains, suggesting that a clear uplift occurred in the eastern part of China during the Late Triassic period when it formed vast mountains and plateaus. A series of molasse-volcanic rock-coal strata developed in the northern margin of North China Craton in the Early Jurassic and are found in the Xingshikou Formation, Nandailing Formation, and Yaopo Formation in the West Beijing Basin. The geological age and markers of the boundary between the Yongfeng Stage and Liuhuanggou Stage are unclear. About 170 Ma ago, the Yanshan Movement began to affect China. The structural system of China changed from the near east-west Tethys or the Ancient Asia Ocean tectonic domain to the north-north-east Pacific tectonic domain since 170–135 Ma. A set of syngenetic conglomerate at the bottom of the Haifanggou or Longmen Fms. represented another set of molasse-volcanic rock-coal strata formed in the Yanliao region during the Middle Jurassic Yanshan Movement(Curtain A1). The bottom of the conglomerate is

关键词： Continental Jurassic Biostratigraphy Isotope chronology Age frame Yanshan Movement Yanliao biota

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A 217-year precipitation reconstruction in the Habahe area, Xinjiang, Northeast China

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Journal of Forestry Research 2024年第6期35卷 242-254页

作者： Heli Zhang Youping Chen Feng Chen Lu Li Huaming Shang Daming He Shengxia Jiang Mao Hu Xiaoen Zhao Weipeng Yue Shijie Wang Honghua Cao Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security Institute of International Rivers and Eco-SecurityYunnan UniversityKunming 650500China Institute of Desert Meteorology China Meteorological Administration/Key Laboratory of Tree-Ring Physical and Chemical Research of China Meteorological Administration/Xinjiang Key Laboratory for Tree Ring EcologyÜrümqi 830002China Xinjiang Meteorological Observatory Ürümqi 830002China

Evaluating long-term changes in precipitation resources is important for accurate hydrological evaluation and forecasting,water security and rational allocation of water *** this purpose in the Xinjiang Habahe area,tree-ring specimens were collected from Picea obovata,Larix sibirica,and Betula platyphylla to establish a tree-ring width chronology,which was used to analyse a correlation with the average temperature and precipitation per month for *** on correlation coefficients for monthly temperature and precipitation with the chronology of tree-ring widths,radial tree growth was mainly restricted by precipitation,and tree-ring width chronology was significantly correlated with overall precipitation from the previous July to the next June(r=0.641,P<0.01).The above results were used to establish a transformation equation,and the overall precipitation from the previous July to the following June from 1800 to 2016 in Habahe was reconstructed after adjusted degrees of freedom,and obtain an explanatory rate of the variation up to 41.1%(40.0%).In addition to the reliability of the reconstructed values,the stability of the conversion function was determined via the“leave-one-out”method,which is commonly used in research on tree rings,and by cross-checking the conversion function with the reduced error value(RE),product mean test(t),with a sign test(ST).During the last 217 years,there were nine dry periods:1803-1829,1861-1865,1872-1885,1892-1905,1916-1923,1943-1954,1961-1966,1973-1981,and 2005-2011;and 12 wet periods:1830-1834,1836-1860,1866-1871,1886-1891,1906-1915,1925-1930,1934-1942,1955-1960,1967-1972,1982-1996,2000-2004,and *** of the reconstructions for neighboring regions and a spatial correlation analysis showed that the reconstructed sequence of the present precipitation data better represented the changes in precipitation in ***,a power spectrum analysis revealed that precipitation over the past 217 years in

关键词： Tree ring chronology Climate response Reconstruction Comparison

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明以降农村土地细碎化研究

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农业考古 2009年第4期 192-198页

作者：任志强肇庆行政学院

Separation system and sale and purchase of land are the reasons of land *** sale and exchange of land are the ways to address land ***,the traditional society can not solve this *** new China was founded,it was Failure to resolve the land chronology by political *** is a correct direction to transfer land in accordance with the principle of law,voluntary and paid.

关键词： land chronology land rural land circulation

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Paleoenvironmental implications of high-density records in Co-rich seamount crusts from the Pacific Ocean

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Science China Earth Sciences 2008年第10期51卷 1460-1469页

作者： WANG XiaoHong ZHOU LiPing WANG YiMin ZHANG XueHua LIU XiaoMing FAN XingTao LIU KeXin ZHOU JianXiong Ministry of Education Key Laboratory for Earth Surface Processes Department of GeographyPeking UniversityBeijing 100871China National Research Center for Geoanalysis Beijing 100037China Guangzhou Marine Geological Survey Guangzhou 510760China The Key Laboratory of Continental Dynamics Northwest UniversityXi’an 710069China The Key Laboratory of Heavy Ion Physics Ministry of EducationPeking UniversityBeijing 100871China Institute of Mineral Resources Chinese Academy of Geological SciencesBeijing 100037China

Co-rich seamount crusts have been shown to possess great potential for providing information on paleoceanographic and paleoclimatic changes. High resolution data are essential to decipher and correctly understand such high-density records. With the development of modern microprobe techniques, detailed sampling of crusts can be performed and it is possible to retrieve detailed information about envi- ronmental changes recorded in the seamount crusts. We report here geochemical results of more than 40 elements (including all rare earth elements) of four Co-rich seamount crust samples, which were collected from seamounts in the central and western Pacific Ocean. These data were obtained with two micro-probe techniques: Electron Probe Micro Analyzer and Laser Ablation Inductively Coupled Plasma Mass Spectrometry. The chronological framework of the seamount crust samples was determined using the cos- mogenic 10Be and the Co-chronometer. Records of elemental composition, P, and Al/(Fe + Mn) and Y/Ho ratios across the sections of the four samples are used to identify paleoceanographic and paleoclimatic events over the past ~30 Ma. These data show that: (1) Al/(Fe + Mn) in the western Pacific seamount crust is a useful proxy for the assessment of changes of source materials related to the variability of the Asian monsoon; (2) P and Y/Ho can be used as proxies to infer biogenic episodes. Finally we discuss the methodology related to dating and micro-probe analysis used in crust study.

关键词： Co-rich seamount crust micro-probe chronology geochemical record paleo-oceanic environment

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Stenian A-type granitoids in the Namaqua-Natal Belt,southern Africa,Maud Belt,Antarctica and Nampula Terrane,Mozambique:Rodinia and Gondwana amalgamation implications

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Geoscience Frontiers 2019年第6期10卷 2265-2280页

作者： Tomokazu Hokada Geoffrey H.Grantham Makoto Arima Satoshi Saito Kazuyuki Shiraishi Richard A.Armstrong Bruce Eglington Keiji Misawa Hiroshi Kaiden National Institute of Polar Research 10-3Midori-choTachikawa-shiTokyo190-8518Japan Department of Polar Science The Graduate University for Advanced Studies10-3Midori-choTachikawa-shiTokyo190-8518Japan Department of Geology University of JohannesburgPO Box 524Auckland Park2006South Africa Geological Institute Yokohama National UniversityYokohama240-8501Japan PRISE Australian National UniversityCanberraAustralia Department of Geological Sciences University of SaskatchewanSaskatoonSaskatchewanS7N 5E2Canada Department of Earth Sciences Ehime UniversityMatsuyama790-8577Japan

We carried out SHRIMP zircon U-Pb dating on A-type granitic intrusions from the Namaqua-Natal Province,South Africa,Sverdrupfjella,western Dronning Maud Land,Antarctica and the Nampula Province of northern *** grains in these granitic rocks are typically elongated and oscillatory zoned,suggesting magmatic *** from the granitoid intrusions analyzed in this study suggest^1025-1100 Ma ages,which confirm widespread Mesoproterozoic A-type granitic magmatism in the Namaqua-Natal(South Africa),Maud(Antarctica)and Mozambique metamorphic *** older inherited(e.g.,~2500 Ma Achean basement or^1200 Ma island are magmatism in northern Natal)zircon grains were *** plutons from the Natal Belt(Mvoti Pluton,Glendale Pluton,Kwalembe Pluton,Ntimbankulu Pluton)display 1050-1040 Ma ages,whereas the Nthlimbitwa Pluton in northern Natal indicates older 1090-1080 Ma ages.A sample from Sverdrupfjella,Antarctica has^1091 Ma old zircons along with^530 Ma metamorphic ***,four samples analysed from the Nampula Province of Mozambique suggest crystallization ages of^1060-1090 Ma but also show significant discordance with two samples showing younger^550 Ma *** of the Natal samples show any younger overgrowths.A single sample from southwestern Namaqualand yielded an age of^1033 *** available chronological data suggest magmatism took place in the Namaqua-Natal-MaudMozambique(NNMM)belt between^1025 Ma and^1100 Ma with two broad phases between^1060-1020 Ma and 1100-1070 Ma respectively,with peaks at between^1030-1040 Ma and^1070-1090 *** age data from the granitic intrusions from *** with those from Natal,Antarctica and Mozambique suggest a crude spatial-age relationship with the older>1070 Ma ages being largely restricted close to the eastern and western margins of the Kalahari Craton in northern Natal,*** and WDML Antarctica whereas the younger<1060 Ma ages dominate in southern Natal and we

关键词： A-type granites Mesoproterozoic Natal South Africa Maud Antarctica Mozambique Southern Africa Sri Lanka Zircon chronology

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New Chronological Evidence for Indosinian Diagenetic Mineralization in Eastern Xinjiang, NW China

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Acta Geologica Sinica(English Edition) 2005年第2期79卷 264-275页

作者： LIHuaqin CHENFuwen LUYuanfa YANGHongmei GUOJing MEIYuping YichangInstituteofGeologyandMineralResources 37GangyaoRoadYichangHubei443003

There have been conflicting ideas about the Indosinian mineralization in E. Xinjiang, a subject that has attracted many geologists' attention over a long period. Isotopic dating shows that the Shiyingtan gold deposit located on the southern margin of the Turpan-Hami basin has a quartz fluid inclusion Rb-Sr isochron age of 237±9 Ma (95% conf.); the Shuangfengshan gold deposit on the southern margin of the Junggar orogenic belt has a quartz fluid inclusion Rb-Sr isochron age of 226 ±21 Ma (95% conf.); the Weiya vanadium-titanium magnetite in the E. Tianshan mountains has a mineral-whole rock Sm-Nd isochron age of 220 ±30 Ma (95% conf.); the Jinwozi and Jinwozi 210 gold deposits in the E. Tianshan mountains have quartz fluid inclusion Rb-Sr isochron ages of 228±22 Ma (95% conf.) and 230±6 Ma (95% conf.), respectively; and the Xiaobaishitouquan scheelite deposit in the E. Tianshan mountains has a quartz fluid inclusion Rb-Sr isochron age of 248±7 Ma (95% conf.). The metallogenetic ages mentioned above prove the existence of Indosinian mineralization in E. Xinjiang, and the metallogenetic event might have been related to Triassic intraplate magmatic evolution, intra-continent subduction, strike-slip shoving and ductile shearing in the studied area, representing another mineralization peak after the Late Paleozoic.

关键词： Indosinian mineralization representative deposits chronology E. Xinjiang

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A Date Recovery System launched for chronological studies in ancient China

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Science China(Physics,Mechanics & Astronomy) 2008年第1期51卷 105-110页

作者： LI Yong National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100012,China National Astronomical Observatories Chinese Academy of Sciences Beijing China

Benefited from the performance of the Xia-Shang-Zhou chronology Project(XSZP) in China and our new astronomical chronology method designed and processed for Chinese particular 60-day-cycle Ganzhi(the heavenly stems and earthly branches)date records,we launch a Date Recovery System(DRS)for ancient China. Of high analysis function,this software can recover and convert the complete or incomplete date information originally from Ganzhi style in the historical period of China to the Gregorian Calendar System,which may have wide applications in the area of literary history,archaeology and cultural relic,etc.,and solve the Goldbach Puzzles of Chinese *** an example,we give the detailed process for the sculptures on four bronze wares with the Ganzhi data and afterwards employ this software and provide their possible dates corresponding to Gregorian system.

关键词： chronology date ephemeris software

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Assessment of widely used methods to derive depositional ages from detrital zircon populations

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Geoscience Frontiers 2019年第4期10卷 1421-1435页

作者： Daniel S.Coutts William A.Matthews Stephen M.Hubbard Department of Geoscience University of Calgary

The calculation of a maximum depositional age(MDA)from a detrital zircon sample can provide insight into a variety of geological ***,the impact of sample size and calculation method on the accuracy of a resulting MDA has not been *** use large populations of synthetic zircon dates(N≈25,000)to analyze the impact of varying sample size(n),measurement uncertainty,and the abundance of neardepositional-age zircons on the accuracy and uncertainty of 9 commonly used MDA calculation ***,a new method,the youngest statistical population is *** each method,500 samples of n synthetic dates were drawn from the parent population and MDAs were *** mean and standard deviation of each method ove r the 500 trials at each n-value(50-1000,in increments of 50)were compa red to the known depositional age of the synthetic population and used to compare the methods quantitatively in two simulation *** first simulation scenario varied the proportion of near-depositional-age grains in the synthetic *** second scenario varied the uncertainty of the dates used to calculate the *** sample size initially decreased the mean residual error and standard deviation calculated by each *** higher n-values(>~300 grains),calculated MDAs changed more slowly and the mean resid ual error increased or decreased depending on the method *** the p roportion of near-depositional-age grains and lowering measurement uncertainty decreased the number of measurements required for the calculated MDAs to stabilize and decreased the standard deviation in calculated MDAs of the 500 *** of the two simulation scenarios show that the most successful way to increase the accuracy of a calculated M DA is by acquiring a large number of low-uncertainty measurements(300300)approach is used if the calculation of accurate MDAs are key to research *** acquisition method s,such as high-to moderate-precision m

关键词： Detrital zircon Maximum depositional age Geochronology Basin chronology LA-ICP-MS

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