珊瑚礁岩的磁性初步研究  

A PRELIMINARY STUDY ON THE MAGNETISM OF CORAL REEF

作　　者：汤贤赞[1] 袁友仁[1] 王保贵[1] 侯红明[1] 赵焕庭[1] 朱袁智[1] 

机构地区：[1]中国科学院南海海洋研究所

出　　处：《热带海洋》1995年第4期51-57,共7页

摘　　要：南沙群岛南永１井珊瑚礁岩的磁性测量结果表明，珊瑚礁岩的磁化率（Ｘ）为负值，属抗磁性物质，但它有较稳定的剩余磁化强度（Ｍｒ），而且它的ＮＲＭ（天然剩余磁化强度）近似对数正态分布，其值大部分分布在（０．８－１．６）×１０（－４）Ａ·ｍ（－１）区间内。进一步研究发现珊瑚在生长过程中，富铁细菌及水介质等可以在珊瑚礁孔隙中留下铁磁性物质；另一方面，珊瑚在生长时也可能吸收铁离子，变成珊瑚礁骨骼的一部分。因此，珊瑚礁岩具有铁磁性，在古地磁场作用下，产生弱剩磁。The magnetic study on coral reef from Nanyong 1 well in Nansha Islands shows that susceptibility (X) is negative and the material is diamagnetic. It also has Natural Remanent Magnetization (NRM), which has approximately a logarithmic normal distri bution, and intensity mainly falls in a range of 0.8-1. 6×10(-4)A·m(-1). Our study indicates that Fe-bearing bacteria and Fe in sea water medium may be deposited in the pores of the coral reef when it grows. In the process of coral reef growth, ferro-ions are absorbed and become a part of the coal reef skeleton, therefore the coral reef has ferromagvietic material which under affect of the geomagnetic. field produces remanent magnetization.

关 键 词：磁化率 剩余磁化强度 珊瑚礁岩 南沙群岛 

分 类 号：P588.248[天文地球—岩石学]