Changes in diffuse reflectance spectroscopy properties of hematite in sediments from the North Pacific Ocean and implications for eolian dust evolution history  

作　　者：Qiang Zhang QingSong Liu 

机构地区：[1]University of Chinese Academy of Sciences,Beijing 100049,China [2]State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [3]Department of Ocean Science&Engineering,Southern University of Science and Technology,Shenzhen 518055,China [4]Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266061,China

出　　处：《Earth and Planetary Physics》2018年第4期342-350,共9页地球与行星物理（英文版）

基　　金：supported by the National Key R&D Program of China (2016YFA0601903);the NSFC-Shandong Joint Fund for Marine Science Research Centers (U1606401);National Program on Global Change and Air–Sea Interaction (GASI-GEOGE-03);the National Natural Sciences Foundation of China (41430962)

摘　　要：Eolian dust preserved in deep-sea sediments of the North Pacific Ocean(NPO) is an important recorder of paleoclimatic and paleoenvironmental changes in the Asian inland. To better understand changes in the dust provenances, in this study diffuse reflectance spectroscopy(DRS) was used to extract the eolian signal recorded in sediments of ODP Hole 885 A recovered from the NPO. First, we systematically investigated sieving effects on the DRS data; then band positions of hematite(obtained from the second order derivative curves of the K-M remission function spectrum derived from the DRS) were used to distinguish different provenances of the eolian dust preserved in the pelagic sediments of this hole. Our results show that the sieving(38 μm) process can suppress effectively the experimental errors. Eolian signatures from Chinese Loess Plateau(CLP) sources and non-CLP-sources have been identified in the pelagic sediments of ODP Hole 885 A from the late Pliocene to the early Pleistocene. The provenance differences account for the discrepancies in the eolian records recovered from the pelagic sediments in the NPO and profiles in the CLP. Temporal changes in dust provenances are caused by the latitudinal movement of the westerly jet mainstream. The hematite DRS band position is a useful tool to distinguish the provenance of eolian components preserved in pelagic sediments.Eolian dust preserved in deep-sea sediments of the North Pacific Ocean(NPO) is an important recorder of paleoclimatic and paleoenvironmental changes in the Asian inland. To better understand changes in the dust provenances, in this study diffuse reflectance spectroscopy(DRS) was used to extract the eolian signal recorded in sediments of ODP Hole 885 A recovered from the NPO. First, we systematically investigated sieving effects on the DRS data; then band positions of hematite(obtained from the second order derivative curves of the K-M remission function spectrum derived from the DRS) were used to distinguish different provenances of the eolian dust preserved in the pelagic sediments of this hole. Our results show that the sieving(38 μm) process can suppress effectively the experimental errors. Eolian signatures from Chinese Loess Plateau(CLP) sources and non-CLP-sources have been identified in the pelagic sediments of ODP Hole 885 A from the late Pliocene to the early Pleistocene. The provenance differences account for the discrepancies in the eolian records recovered from the pelagic sediments in the NPO and profiles in the CLP. Temporal changes in dust provenances are caused by the latitudinal movement of the westerly jet mainstream. The hematite DRS band position is a useful tool to distinguish the provenance of eolian components preserved in pelagic sediments.

关 键 词：EOLIAN DUST DIFFUSE reflectance spectroscopy HEMATITE 

分 类 号：P35[天文地球—空间物理学]