胜利油田惠民凹陷辉绿岩中黑云母矿物化学

MINERAL CHEMISTRY OF BIOTITEIN DIABASE FROM THE HUIMIN DEPRESSION IN THE SHENGLI OILFIELD, SHANDONG PROVINCE,CHINA

黑云母是胜利油田惠民凹陷辉绿岩中的次要矿物,以斑晶、基质和次生云母三种产状产出,其中斑晶云母绝大部分已被绢云母、碳酸盐、石英和磁铁矿等替代。本文分析了基质和次生云母的化学成分,发现两者的成分具有明显差别,在云母分类命名图上,前者投于富镁黑云母和镁铁黑云母之间,后者落在富铁黑云母区域。基质云母化学成分判别本区辉绿岩主要属碱性系列、部分为钙碱性系列,同时指示成岩过程中存在较明显的地壳物质混染作用和结晶分异作用。

Biotite is a minor mineral of diabase from the Huimin depression in the Shengli oilfied, Shandong Province, China and can be divided into three occurrences, namely phenocryst, matrix and secondary mica. Most of the mica phenocrysts have been replaced by sericite, carbonate, quartz, magnet, etc. This paper mainly analyzed the chemical composition of the matrix and secondary micas and pointed out that both micas show obvious differences as seen in the figure of classification and nomenclature, the former plot between eastonite and svitalskite and the latter plot in the ferribiotite region. In the light of the chemical composition of matrix mica, the diabase in this area belongs mainly to alkaline series and some samples belong to calc-alkaline series. Moreover, the chemical composition of matrix mica indicate sobvious contamination by crustal materials and crystallization fractionation in the diagenesis process of diabase.