莱恩海山链富钴结壳新壳层标志物的成分特征  

GEOCHEMISTRY OF A MAKER OF YOUNGER DEPOSIT OF CO-RICH FERROMANGANESE CRUST FROM LINE ISLANDS

作　　者：任向文[1] 刘季花[1] 石学法[1] 尹京武[2] 

机构地区：[1]海洋沉积与环境地质国家海洋局重点实验室国家海洋局第一海洋研究所,青岛266061 [2]中国地质大学,北京100083

出　　处：《海洋地质与第四纪地质》2011年第3期41-46,共6页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(40806027);科技部国际科技合作重大项目(2006DFB21620);国际海底区域研究开发"十一五"课题(DYXM-115-01-2-1);国家海洋局第一海洋研究所基本科研业务费专项资金项目(2008T03;GY02-2009G23);"泰山学者"建设工程专项经费

摘　　要：在莱恩海山链MP2海山的一块富钴结壳样品新壳层中,发育有"褐红色碎屑物质",这种物质粒度细小,呈浸染状分布,以Fe-Mn壳层柱状结构间的填隙物的形式产出。基于对该海区结壳样品手标本和光片的观察,认为这种"褐红色碎屑物质"可作为新壳层的一个标志物。利用电子探针技术,对这块富钴结壳样品进行了分析,获得了该结壳新壳层中"褐红色碎屑物质"及其周边Fe-Mn壳层的成分数据,Fe、Mn元素含量的面扫描数据和新壳层成分数据。数据显示,MP2海山富钴结壳样品新壳层属于典型的水成成因铁锰沉积,其中发育的"褐红色碎屑物质"的成分以Fe、Si、Al为主,而Mn含量相对Fe-Mn壳层则非常低。据其成分特点、形态和MP2海山所处高生产力的古海洋背景,认为这种结壳新壳层的"褐红色碎屑物质"最可能为海洋中自生的Fe-Si-Al胶体沉积。A reddish-brown detrital material has been discovered,which is obviously younger than the Co-rich ferromanganese crust,from the seamount MP2 of the Line Islands.The material is fine in grain size,and occurs in the interstices between the columns of Fe-Mn oxides.Based on the observation of hand specimen and polished sections of Co-rich ferromanganese crusts from the Line Islands,it can be concluded that this reddish-brown detrital material can be used as a marker of a younger deposit in ferromanganese crusts.The reddish-brown detrital material and the Fe-Mn oxides around it were investigated geochemically by electron-probe microanalysis（EPMA）.EPMA data suggest that the Co-rich ferromanganese crust is hydrogenetic in origin,and the chemical composition of the reddish-brown detrital material is characterized by Fe,Si and Al,and a lower Mn in comparison with the Fe-Mn oxides around it.Base on the geochemical characteristics and morphology of the reddish-brown detrital material,and with reference to the high primary productivity in the area around the seamount MP2,it is supposed that the reddish-brown detrital material is most probably a kind of authigenic Fe-Si-Al colloidal precipitation from seawater younger than the Co-rich ferromanganese crusts.

关 键 词：碎屑物质 富钴结壳 莱恩海山链 

分 类 号：P744.3[天文地球—海洋科学]