Astronomical Cycles of the Late Permian Lopingian in South China and Their Implications for Third-Order Sea-Level Change  

作　　者：WANG Xiuqi ZHANG Xunhua GAO Fei ZHANG Minghua 

机构地区：[1]College of Marine Geosciences,Ocean University of China,Qingdao 266100,China [2]Qingdao Institute of Marine Geology,China Geological Survey,Qingdao 266071,China [3]Qingdao Jimo Municipal Transport Bureau,Qingdao 266200,China [4]The Brigade of Geological Survey of Ganxi,Bureau of Geologic Exploration and Mineral Development of Jiangxi Province,Nanchang 330002,China

出　　处：《Journal of Ocean University of China》2020年第6期1331-1344,共14页中国海洋大学学报（英文版）

基　　金：This work was supported by a National Natural Science Foundation of China(Grant No.91958210);the Government Finance Level II Project(No.DD20190083);‘the 13th Five-Year Plan’National Science and Technology Major Project(No.2016ZX05034001-003).

摘　　要：The late Permian(Lopingian)was a crucial climate transition period from the late Paleozoic Ice Age to the early Triassic of exceptionally high temperatures.However,the origins of the third-order sea-level changes during the Lopingian Epoch remain unclear.Here,we presented astronomically calibrated gamma-ray(GR)log and non-U GR(computed gamma ray or CGR)curves from the clastic and carbonate successions of well GFD-1 in the Pingle Depression of South China for studying the sea-level oscillations during the Lopingian.Spectral analyses of the 405 kyr-calibrated GR and CGR time data revealed periodicities close to about 405,about 100,about 44.2,about 35.1,about 21,and about 17.5 kyr,supporting the existence of Milankovitch forcing in the sedimentary records.A high-resolution astronomical time scale and high-resolution sedimentation rate curve of the Lopingian from well GFD-1 were constructed by cyclostratigraphic analysis.The eccentricity and obliquity amplitude modulation cycles suggested long periodicities of about 2.4 and about 1.2 myr,respectively.In the Wuchiapingian greenhouse of the Lopingian,the about 2.4 myr eccentricity oscillation controlled‘weak’glacio-eustasy and/or aquifer eustatic changes related to the global third-order sea-level changes and that a lowstand(W2)was initiated by an eccentricity oscillation minimum.In contrast,during the Changhsingian,which exhibited a cooling event,an about 1.2 myr obliquity cycle was probably strong,with the sea-level records highlighting the link between the‘icehouse’sea-level lowering(C2 and C1)and the obliquity nodes.Moreover,dynamic sedimentary noise model as an indicator of sea-level showed local third-order sea-level variations,the coevolution trends in the orbital power,global and local sea-level changes,and sedimentation rate had significant implications for establishing the global nature and synchronicity of these million-year-scale eustatic records and reconstructing the temporal depositional history at a regional scale.In addition,the volcanism and t

关 键 词：LOPINGIAN Milankovitch cycle third-order eustasy long-period astronomical cycle sedimentation rate 

分 类 号：P534.46[天文地球—古生物学与地层学] P736.22[天文地球—地质学]