强风化条件下基性岩的识别方法——以赞比亚卡皮萨比地区为例  

Methods for Identifying Gabbros under Heavily Weathering Conditions——A Case Study from Kapisabi area,Zambia

作　　者：段毅君[1] 高阳[2] 陈建平[1] 陈东越[1] 

机构地区：[1]中国地质大学(北京),北京100083 [2]核工业北京地质研究院,北京100029

出　　处：《地质与勘探》2014年第2期332-339,共8页Geology and Exploration

摘　　要：赞比亚卢菲利安弧中西段有大量辉长岩体发育。由于本区风化严重,辉长岩常被厚土壤层覆盖。辉长岩中的铜含量常高于其沉积围岩,易于形成铜异常。为了将辉长岩形成的异常与矿致异常区别开,有必要对土壤覆盖层下的辉长岩进行识别。作者对卡皮萨比地区的化探数据采用相关分析和因子分析进行了研究,认为铜异常与基性岩浆作用有关。根据野外地质观察、音频大地电磁测量、高精度磁法测量、槽探和钻探等工作,认为:地表砖红色土壤、高磁高阻地质体和Sc-Ti-V-Fe-Co-Ni-Cu的元素组合是识别强风化条件下隐伏基性岩体的标志。There are many gabbros occurred in the middle and western part of the Lufilian arc,Zambian. Gabbros used to be covered by thick soil layers because of being heavily weathered. Copper in gabbros is normally higher than in sedimentary rocks,which makes it to form copper anomaly. In order to distinguish anomalies caused by gabbro and those caused by mineralization,it is necessary to identify gabbros under soil cover. Correlation analysis and factor analysis were used to analysis the geochemical data in Kapisabi area,which shows that copper anomaly is related to basic magma. Based on field geology,audio Magnetotellurics survey,high resolution magnetic survey,pitting and drilling results,the signature for identifying covered basic rocks are : red soil,geologic body with high magnetic intensity and the elements combination composed of Sc,Ti,V,Fe,Co,Ni and Cu.

关 键 词：隐伏辉长岩体 因子分析 地球化学 地球物理 

分 类 号：P588.124[天文地球—岩石学]