新疆塔什库尔干碱性杂岩体主要由苦子干碱性正长岩体和卡日巴生碱性花岗岩体组成,是帕米尔地区最大的新生代碱性杂岩体。本文在岩相学和矿物化学的基础上,着重研究了苦子干岩体主要造岩矿物的种属、共生关系和结晶顺序。研究表明,苦子干岩体中的不同岩石类型系同源岩浆演化的产物;岩浆在整个演化过程中平衡结晶作用占主导,分离结晶作用的影响极小。据岩浆房中矿物结晶时的温度和压力条件、矿物的结晶特征及演化趋势,推测岩浆上升速度较快,侵位较浅。
Taxkorgan complex, mainly composed of alkaline syenites and subalkaline granitoids, is the largest Cenozoic alkaline complex in Pamirs region. Based on geography and geochemistry of the rock-forming minerals in Kuzigan intrusion, this paper discusses the classification, intergrowth, and crystalline sequence of minerals. The mineralogical characteristics suggest that different rock types of Kuzigan intrusion are products of the same magma, and that the magma, instead of being affected much by fractional crystallization, has dominantly experienced equilibrating crystallization. According to temperature, pressure, and chemical evolution of mineral crystallization in the magma chamber, it is held that the magma of intrusive rocks ascended rather fast and was emplaced at the relatively shallow place.