投稿时间：2022-04-11
修订日期：2023-03-06
网络发布日期：2023-05-06
中文摘要:阿日特克山铜钼矿床位于青海柴北缘成矿带中北部，为宗务隆构造带新发现的矽卡岩型-斑岩型矿床，矿床隐伏斑岩体中广泛发育黑云母，部分地段还发育角闪石。文章在野外地质工作的基础上，对花岗闪长（斑）岩进行了详细的岩相学研究和黑云母、角闪石成分的电子探针原位分析，初步探讨了成岩过程中的物理化学条件、成岩物质来源及其对成岩成矿的指示作用。电子探针结果显示，花岗闪长（斑）岩中黑云母主要为镁质黑云母，具有高Mg、Ti、K、Fe，低Ca、Na的特点；角闪石为镁质普通角闪石，表现为富Si、Mg、Ca，低Ti、Na、K的特征。黑云母和角闪石温度计算结果显示，花岗闪长（斑）岩中黑云母结晶温度为632~736℃（平均696℃），角闪石结晶温度为737~764℃（平均749℃）；在黑云母和角闪石同时存在的花岗闪长岩中计算的岩体侵位压力为81~180 MPa，深度为3.07~6.82 km，为中深成斑岩体。黑云母和角闪石矿物化学特征指示花岗闪长（斑）岩属于钙碱性岩系I型花岗岩，具有壳幔混源的特征。岩体中黑云母、角闪石具有较高的结晶温度，其结晶的岩浆具有高的氧逸度及水含量，显示良好的成矿性，指示该地区具有寻找大型斑岩矿床的潜力。
Abstract:The Aritekeshan Cu-Mo deposit is located in the central part of the northern margin of Qaidam Metallogenic belt, Qinghai Province. It is a newly-identified skarn-porphyry deposit in the Zongwulong tectonic belt. In this paper, based on the detailed geological work in the field, the petrographic study of the granodiorite (porphyry) and the in-situ electron probe micro analysis (EPMA) of biotite and hornblende are carried out, and the physical and chemical conditions during magma emplacement, the source of rock-forming materials and their indication to mineralization are discussed. The EPMA results show that the biotite in granodiorite is mainly magnesium biotite with high Mg, Ti, K, Fe and low Ca, Na. The amphibole belongs to magnesium hornblende that is rich in Si, Mg, Ca and low in Ti, Na, K. The estimated results of biotite and hornblende thermometers show that biotite and hornblende in granodiorite crystallized at 632~736℃ (average 696℃) and 737~764℃ (average 749℃), respectively. The calculated emplacement pressure of the granodiorite from biotite and hornblende barometers is 81~180 MPa, equivalent to a depth of 3.07~6.82 km, indicating that the granodiorite formed at a medium-deep depth. The chemical characteristics of biotite and hornblende indicate that the granodiorite belongs to calc-alkaline I-type granite, which potentially reflected a crust-mantle interaction process. The biotite and hornblende geochemical analysis data in the ore-forming porphyry show good mineralization condition, including high mineralization temperature, high oxygen fugacity and water abundance, which indicate that the area might have prospecting potential for large-size porphyry deposits.
keywords:geology hornblende biotite mineralogical characteristics Aritekeshan Cu-Mo deposit northern Qaidam Basin
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基金项目:本文得到山东省深部金矿探测大数据应用开发工程实验室开放课题（编号：SDK202205）和山东省地矿局局控地质勘查与科技创新项目（编号：202013）联合资助
引用文本：
唐名鹰,丁正江,彭永和,陈建,张琪彬,朱伟,朱海波,马登贤,孙晓亮.2023.柴北缘阿日特克山铜钼矿床成矿岩体中黑云母和角闪石矿物学特征及其指示意义[J].矿床地质,42(2):253~266TANG MingYing,DING ZhengJiang,PENG YongHe,CHEN Jian,ZHANG QiBin,ZHU Wei,ZHU HaiBo,MA DengXian,SUN XiaoLiang.2023.Mineralogical characteristics of hornblendes and biotites in ore-forming porphyry from Aritekeshan Cu-Mo deposit in northern Qaidam Basin and their significance[J].Mineral Deposits42(2):253~266
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