CAJ | 학술논문

式可布台铁矿位于西天山阿吾拉勒铁矿成矿带西段，是此矿带极具代表性的铁矿床。主要赋存于以凝灰岩为主的石炭系上统伊什基里克组火山岩中。本文通过对式可布台矿区的火山岩进行岩石地球化学和LA-ICPMS锆石U-Pb测年分析来探讨火山岩形成的构造环境与成岩时代。地球化学分析表明大多数火山岩样品显示为高钾钙碱性系列；主量元素表明矿区火山岩主要由安山岩、英安岩、流纹英安岩组成，为钙碱性系列；微量元素和稀土元素表明矿区火山岩产出的构造环境为火山岛弧；LA-ICPMS锆石U-Pb测年显示火山岩的206Pb/238U加权平均年龄分别为（301±1）Ma和（313±2）Ma，表明该区的火山岩为晚石炭世早期。结合区域地质资料，认为矿区内出露的高钾钙碱性系列火山岩可能属于俯冲过程末期大陆岛弧岩浆作用的产物，其岩石的形成与构造岛弧环境有关，主体与下石炭统大哈拉军山组火山岩岩石化学特征相似。
식가포태철광위우서천산아오랍륵철광성광대서단，시차광대겁구대표성적철광상。주요부존우이응회암위주적석탄계상통이십기리극조화산암중。본문통과대식가포태광구적화산암진행암석지구화학화LA-ICPMS고석U-Pb측년분석래탐토화산암형성적구조배경여성암시대。지구화학분석표명대다수화산암양품현시위고갑개감성계렬；주량원소표명광구화산암주요유안산암、영안암、류문영안암조성，위개감성계렬；미량원소화희토원소표명광구화산암산출적구조배경위화산도호；LA-ICPMS고석U-Pb측년현시화산암적206Pb/238U가권평균년령분별위（301±1）Ma화（313±2）Ma，표명해구적화산암위만석탄세조기。결합구역지질자료，인위광구내출로적고갑개감성계렬화산암가능속우부충과정말기대륙도호암장작용적산물，기암석적형성여구조도호배경유관，주체여하석탄통대합랍군산조화산암암석화학특정상사。
Located in the western part of the West Tianshan Awulale iron metallogenic belt, the Shikebutai iron deposit is a representative deposit in this belt. It mainly occurs in the Carboniferous Yishijilike Formation volcanic rocks dominated by tuff. Based onj rock geochemistry and LA-ICPMS zircon U-Pb dating of volcanic rocks in the Shikebutai iron deposit, this paper discusses the tectonic environment and petrogenic age of the volcanic rocks. Geochemical analysis shows that most of the volcanic rocks vary from high potassium calc-alkaline volcanic rocks to shoshonite series in chemical composition. The major elements indicate that volcanic rocks are mainly composed of andesite, dacite, rhyolite and dacite, belonging to calc-alkaline series. Trace elements and rare earth elements indicate that the tectonic environment for the formation of the volcanic rocks was active epicontinental volcanic arc. LA-ICPMS zircon U-Pb dating shows that 206Pb/238U weighted average ages of volcanic rocks are 301± 1Ma and 313±2Ma, suggesting that volcanic rocks in this deposit were formed in early Late Carboniferous. Combined with regional geological data, the authors hold that the high-K calc-alkaline volcanic rocks of shoshonite series in the ore district may be the product of the late subduction of continental arc magmatism, and the tectonic environment for the formation of the volcanic rocks was active epicontinental arc. The chemical characteristics of the volcanic rocks are on the whole similar to features of Lower Carboniferous Dahalajunshan Formation volcanic rocks.