哈萨克斯坦阿克斗卡超大型斑岩型铜矿田地质特征与成矿模式

中亚成矿域巴尔喀什成矿带阿克斗卡矿田主要由阿克斗卡、艾达里和库兹尔基亚等矿床组成, 是发育在火山岛弧环境的典型斑岩型Cu-Mo-Au矿床群, 其中阿克斗卡为超大型斑岩铜矿。斑岩型铜成矿作用发生在晚古生代哈萨克马蹄形构造形成过程中, 成矿构造背景为乌拉尔-天山断裂系统的大型左行走滑作用和大陆地壳侧向增生过程, 具有典型的斑岩铜矿围岩蚀变和矿石矿物分带特征; 成矿作用受东西向、北东东向和北西西向断裂控制, 主要与早期碱性阶段的硅化蚀变有关, 酸性蚀变阶段发生了再矿化与富集成矿作用; 据含矿花岗闪长岩中锆石SHRIMP定年本文给出主要成矿时代为327.5 ± 1.9 Ma (早石炭世晚期), 成矿模式为"花岗闪长岩"型, 属于浅成斑岩铜矿成矿系统。 

GEOLOGICAL CHARACTERISTICS AND METALLOGENIC MODEL OF SUPER-LARGE PORPHYRY COPPER DEPOSIT IN AKTOGAI ORE FIELD,KAZAKHSTAN

The Aktogai ore field consists of a group of porphyry Cu-Mo-Au deposits, such as Aktogai, Aidarly, and Kyzylkia deposits, in the Balkhash Metallogenic Belt of the Central Asian Metallogenic Domain. They are formed in the Balkhash volcanic arc of the north-central margin of Kazakhstan Orocline due to the large left-leteral strike-slip movement of the Ural-Tianshan Fault System and lateral crust-growth in the Late Paleozoic. Among them, the Aktogai deposit is a superlarge porphyry Cu-Mo-Au deposit. All of them are porphyry deposits with typical zoning of wallrock alterations and mineral assemblages. The metallogenesis is mainly related to the silicification of the early-stage alkaline alteration and the redeposition in the acid alteration stage. The occurrence of ore-bodies is controlled by the E-W, ENE, and WNW trending faults. The SHRIMP zircon dating of granodiorite has given the Aktogai deposit a metallogenic age of 327.5 ± 1.9 Ma in the late period of the Early Carboniferous. The deposit model of the porphy deposits in the Aktogai ore field is concluded as "granodiorite" type in the hypabyssal porphyry copper system.