安徽铜陵新桥铜-硫-铁矿床矶头岩体的矿物学和锆石U-Pb年代学及其地质意义
发布时间：2018-10-22 14:14
【摘要】：长江中下游成矿带铜陵矿集区内的许多矿床皆与中生代岩浆岩的侵入密切相关,选取新桥矿床矶头岩体为研究对象,进行LA-ICP-MS锆石U-Pb定年以及岩体地质和矿物学研究。锆石的高Th/U比值特征及典型岩浆锆石环带显示其为岩浆成因。矶头岩体中主体石英闪长岩16个测点的加权平均年龄为(141.6±1.1)Ma,后期侵入的闪长玢岩20个测点加权平均年龄为(129.95±0.6)Ma。两者均形成于早白垩世,矿区内岩浆活动至少有两期,主岩浆作用为141 Ma。矶头岩体是由幔源岩浆上侵至13~15km中地壳先形成深部岩浆房,发生结晶分异和同化混染,随后在构造扰动与岩浆脉动下,深部岩浆房中的岩浆沿构造薄弱面上侵至7~8km,冷凝固结形成,其结晶温度大约为800℃。矶头岩体约束成矿时代及成矿作用,新桥矿床经由高温热液交代作用,并经后期热液多次叠加改造成矿。
[Abstract]:Many deposits in Tongling ore concentration area of the middle and lower reaches of the Yangtze River are closely related to the intrusion of Mesozoic magmatic rocks. The LA-ICP-MS zircon U-Pb dating and the geological and mineralogical study of the rock mass are carried out in this paper. The characteristics of high Th/U ratio of zircon and typical magmatic zircon ring show that it is magmatic origin. Weighted mean age of (141.6 卤1. 1) Ma, intrusive diorite porphyrite from 16 sites in the main quartz diorite is (129.95 卤0. 6) Ma.. Both of them were formed in the early Cretaceous, and magmatic activity in the ore area was at least two periods. The main magmatism was 141 Ma.. The Jitou rock body was intruded from mantle magma to the middle crust of 13~15km to form deep magma chamber, crystallization differentiation and assimilation, and then under tectonic disturbance and magmatic pulsation, The magma in the deep magma chamber infiltrates up to 7 ~ 8 km along the weak surface of the structure and is formed by condensation and consolidation, and its crystallization temperature is about 800 鈩，
本文编号：2287387
[Abstract]:Many deposits in Tongling ore concentration area of the middle and lower reaches of the Yangtze River are closely related to the intrusion of Mesozoic magmatic rocks. The LA-ICP-MS zircon U-Pb dating and the geological and mineralogical study of the rock mass are carried out in this paper. The characteristics of high Th/U ratio of zircon and typical magmatic zircon ring show that it is magmatic origin. Weighted mean age of (141.6 卤1. 1) Ma, intrusive diorite porphyrite from 16 sites in the main quartz diorite is (129.95 卤0. 6) Ma.. Both of them were formed in the early Cretaceous, and magmatic activity in the ore area was at least two periods. The main magmatism was 141 Ma.. The Jitou rock body was intruded from mantle magma to the middle crust of 13~15km to form deep magma chamber, crystallization differentiation and assimilation, and then under tectonic disturbance and magmatic pulsation, The magma in the deep magma chamber infiltrates up to 7 ~ 8 km along the weak surface of the structure and is formed by condensation and consolidation, and its crystallization temperature is about 800 鈩，
本文编号：2287387
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