Paleoclimatic and provenance implications of magnetic parameters from the Miocene sediments in the Subei Basin

作者：YouSheng Li,JiMin Sun,ZhiLiang Zhang,Bai Su,ShengChen Tian,MengMeng Cao

摘要：Thick sediments from foreland basins usually provide valuable information for understanding the relationships between mountain building,rock denudation,and sediment deposition.In this paper,we report environmental magnetic measurements performed on the Miocene sediments in the Subei Basin,northeastern Tibetan Plateau.Our results show two different patterns.First,the bulk susceptibility and SIRM,ARM,and HIRM mainly reflect the absolute-concentration of magnetic minerals;all have increased remarkably since 13.7 Ma,related to provenance change rather than climate change.Second,the ratios of IRM100mT/SIRM,IRM100mT/IRM30mT,and IRM100mT/IRM60mT,together with the redness and S ratio,reflect the relative-concentration of hematite,being climate-dependent.Their vertical changes correlate in general with the long-term Miocene climatic records of marine oxygen isotope variations,marked by the existence of higher ratios between 17 and 14 Ma.This may imply that global climate change,rather than uplift of the Tibetan Plateau,played a dominant role in the long-term climatic evolution of the Subei area from the early to middle Miocene.

發文機構：Key Laboratory of Cenozoic Geology and Environment Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences University of Chinese Academy of Sciences

關鍵詞：EnvironmentalmagnetismMMCOglobalcoolingtheSubeiBasin

分類號： P53[天文地球—古生物學與地層學]