Identification of the thick-layer greigite in sediments of the South Yellow Sea and its geological significances
作者单位：Paleomagnetism and Geochronology Laboratory (SKL-LE)Institute of Geology and GeophysicsChinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of Marine Sedimentation and Environmental GeologyFirst Institute of OceanographyState Oceanic Administration
会议名称：《中国科学院地质与地球物理研究所2014年度（第14届）学术年会》
会议日期：2015年
学科分类：070704[理学-海洋地质] 0709[理学-地质学] 07[理学] 0707[理学-海洋科学]
基 金：supported by the Project of State Oceanic Administration,China (908-01-BC15) the National Natural Science Foundation of China (41374073,41025013 and 40821091)
关 键 词：Rock magnetism Greigite Continental shelf environment South Yellow Sea
摘 要：Magnetic minerals in sediments of the continental shelf are sensitive to environmental ***, to determine the exact phases of magnetic minerals is the prerequisite to investigate the paleoenvironmental significances. In this study, a comprehensive rock magnetic investigation, coupled with mineralogical studies, was carried out on the long core NHH01(with a length of 125.64 m) from the central continental shelf of the South Yellow Sea. Single-domain greigite was identified as the dominant magnetic carrier in sediments between44.90 and 51.80 m, and terrigenous magnetite is the major magnetic phase in the adjacent layers. The existence of greigite unambiguously indicates an anoxic *** tentatively interpreted that such an environment could be formed by the fast sea level changes, long-existing of the cold eddies during warm stages, or in a lake which might be related to locally tectonic uplifting. Therefore, the occurrence of the thick-layer greigite could supply a new perspective to paleoenvironmental or even tectonic studies.