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选取位于南海南部的YSJD-86GC(简称86GC)孔沉积物柱状样进行环境磁学研究,结合已发表的年代框架,揭示MIS3阶段以来沉积物的磁学变化特征.岩石磁学结果表明钻孔沉积物以低矫顽力的磁铁矿类矿物为主要携磁矿物,同时存在部分赤铁矿.反映磁性颗粒大小的King图和Day图表明沉积物中磁性矿物以细粒伪单畴为主.磁学参数与地球化学指标剖面变化的对比分析表明86GC孔沉积物磁性特征反映的是陆源物质的信息;研究钻孔沉积物的磁学性质同时受陆源物质输入量、物源区的氧化-还原条件及搬运环境和距离等多种因素共同影响.全球气候变化引起的海平面升降是导致研究钻孔沉积物中磁性矿物含量和磁性颗粒大小变化的主要原因,沉积物磁学性质的变化可间接指示本地区的海平面升降.
Environmental magnetism studies of YSJD-86GC (86GC) pore sediment samples in the southern part of the South China Sea are carried out to reveal the magnetorheological characteristics of the sediments since the MIS3 stage in combination with the published chronological framework.The rock magnetism results indicate that the borehole sediments The magnetite minerals with low coercivity are the main magnetic minerals and some hematite are present at the same time.The King and Day plots, which reflect the size of magnetic particles, show that the magnetic minerals in the sediments are dominated by fine pseudo-monodomain. Comparison of magnetic parameters and geochemical index profile shows that the magnetic characteristics of the 86GC pore reflect the terrestrial material information. The study of the magnetic properties of borehole sediments is at the same time influenced by the input of terrestrial materials and the oxidation-reduction Conditions and handling environment and distance, etc. The sea level rise and fall caused by global climate change is the main reason for the study of magnetic mineral content and magnetic particle size variation in borehole sediments. The change of magnetic properties of sediments can be indirectly Indicate sea level rise and fall in the area.