福建建宁地区中元古代侵入岩的矿物标型特征及其成因探讨

Typomorphic Characteristics and Genesis of the Minerals from Middle Proterozoic Intrusive Rocks in the Jianning Aera of Fujian Province

摘要福建建宁地区中元古代韩家、严塘二个岩体来自上地幔,其副矿物有28种。副矿物有三个结晶阶段,以富含自然铁、铬铁矿和富铪锆石为特征。锆石具高柱面指数和高锥面指数。变石英闪长岩和变英云闪长岩的锆石类型有二个主型和七个亚型。根据其副矿物标型组合及标型矿物特征,认为其物质来自幔源为主成因的岩浆。

This paper reports on the typomorphic characteristics of the minerals from both theHanjia and Yantang Massifs of Middle Proterozoic in Jianning area of Fujian Province. Thetwo massifs, derived from the upper mantle, have 28 species of accessory minerals such asnatural iron, chromite, zircon, sphene, rutile and so on. The formation of the minerals is inthree crystallization stages. They are characterized by enrichment of natural iron, chromiteand hafnium-rich zircon, and the zircons from the two massifs have high indexes of columnfaces and of pyramid faces. The zircons from the meta-quartz diorite and meta-quartz-micadiorite in the area have two main types and seven subtypes, separately. Based on the typomophiccombination of accessory minerals and the typomorphic characteristics of zircons, itis concluded that the materials constituting the two massifs come from the magam mainly derivedfrom the upper mantle.