新疆西天山色勒特果勒还原性斑岩-矽卡岩铜钼矿床中石榴子石分带及其成因

发布时间：2018-05-19 11:12

本文选题：地质学 + 还原性斑岩矿床　；参考：《矿床地质》2017年02期

【摘要】：新疆色勒特果勒铜钼矿床是形成于晚古生代准噶尔洋向伊犁板块俯冲环境中的斑岩-矽卡岩型矿床。矿体主要产于闪长斑岩、石英闪长斑岩和斑岩体与围岩的接触带矽卡岩中。矿区发育大量的磁黄铁矿,未见原生的磁铁矿、赤铁矿以及石膏等高氧逸度矿物。矿区内的矽卡岩呈层状、似层状产在石炭系东图津河组中。石榴子石在矽卡岩中大量发育,是矽卡岩中最主要的造岩矿物,根据其颜色和形态的变化,主要可以分为3类:(1)内矽卡岩及岩体中的红色石榴子石;(2)岩体与灰岩接触带矽卡岩中的棕色石榴子石;(3)靠近灰岩的灰绿色石榴子石。流体包裹体激光拉曼分析结果显示,矿区内流体包裹体的气相成分大部分为甲烷(CH_4),结合矿区内大量发育的低氧逸度矿物,说明色勒特果勒是一个还原性的斑岩-矽卡岩型矿床。文章对不同类型的石榴子从中心向边缘做了详细的电子探针分析。结果显示,3种石榴子石成分都以钙铝榴石为主,说明这些石榴子石是在酸性还原的条件下形成的。棕色石榴子石具有明显的振荡环带,端员组分随着振荡环带的变化具有较明显差异,其振荡环带有效的记录了成矿热液的演化过程,为示踪成矿流体组成、性质和氧逸度变化提供了重要的信息。
[Abstract]:The Selertgol copper and molybdenum deposit in Xinjiang is a porphyry skarn type deposit formed in the late Paleozoic Junggar Ocean subduction environment towards the Yili plate. Ore bodies mainly occur in diorite quartz diorite and skarn in contact zone between porphyry and surrounding rock. There are a lot of pyrrhotite, no primary magnetite, hematite, gypsum and other high oxygen fugacity minerals. The skarn in the mining area is stratiform, similar to that occurring in the Carboniferous Dongtujin River formation. Pomegranate is the most important rock-forming mineral in skarn, which is developed in large quantities in skarn, according to its color and shape change. It can be divided into three types: skarn and red garnet in the rock mass) and the brown garnet in skarn in the contact zone) and the gray-green garnet in the contact zone near the limestone. The results of laser Raman analysis of fluid inclusions show that the gas composition of fluid inclusions in the ore area is mostly methane CH4D. Combined with a large number of low oxygen fugacity minerals developed in the mining area, Seletegol is a reductive porphyry skarn deposit. A detailed electron probe analysis of different types of pomegranate from center to edge was carried out. The results showed that the three kinds of garnet were mainly composed of calcium and aluminum garnet, which indicated that the pomegranate was formed under the condition of acid reduction. Brown pomegranate has obvious oscillating ring zone, and its end member component has obvious difference with the change of oscillating ring zone. Its oscillating ring zone can effectively record the evolution process of ore-forming hydrothermal solution, which is the composition of trace ore-forming fluid. Changes in properties and oxygen fugacity provide important information.
【作者单位】：中国科学院地球化学研究所矿床国家重点实验室;中国科学院大学;中国冶金地质总局中南地质勘查院;
【基金】：国家自然科学基金面上项目(编号:41272114) 西部之光项目基金(编号:SKLODG-ZY125-03)联合资助
【分类号】：P618.41;P618.65

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