新疆富蕴县科克别克提基性岩体结晶分异及自变质作用探析

富蕴县科克别克提铁镁质基性岩呈黑—灰黑色,中粗粒结构、溶蚀结构、块状结构。岩体经历了岩浆结晶分异,形成闪长岩相—辉长岩相—角闪辉石岩相,其SiO_2含量分别为52%～69%,45%～52%,40%～45%,m/f值为0. 5～2. 0,岩体具有铜镍矿成矿前景,角闪辉石岩为主要控矿岩相。辉石主要为透辉石、普通辉石,少量古铜辉石,多呈"残晶"被角闪石包含;角闪石主要有普通角闪石、透闪石、韭闪石等,部分角闪石保留了辉石的外形。分析表明,岩体经历了自变质作用,发育次闪石化、绿帘石—奥长石化蚀变。

Analysis of the crystallization differentiation and thermal metamorphism of Kekebieketi basic rocksin Fuyun,Xinjiang

Theoutcropped spheroidal hornblendite,coarse-grained-megacryst hornblendite, and coarse-grained-megacryst hornblende pyroxenite inKekebieketi femic basic rocks appear in black-grayblack with medium coarse-grained and dissolution textures, and massive structure. The rocks mass has experienced the magmatic crystallization differentiation resulted in the formation of diorite-gabbro-amphibole pyroxenite phases with the content of silicon is of 52-69%, 45-52%, 40-45% respectively and the value of m/f =0.5-2.0. Amphibole pyroxenite is the main Ore-bearing lithofacies, therefore, there are metallogenic prospects of copper and nickel deposits in this area. The main rocks of pyroxenite are diopside and augite, with minor bronzite which presentsas malcrystalline surrounded by amphibole. The main rocks of pyroxenite are hornblende, tremolite, etc., and some of which is still in the shape of pyroxenite. The results of analysis shows that the rocks experienced autometamophism and results inthe development of alteration of ouralitization epidote-oligoclase.