甘肃金川二矿区岩体橄榄石组构特征研究  

Fabric Characteristics of the Olivine from No.2 Mining Area in the Jinchuan Deposit,Gansu Province

作　　者：王辰[1] 刘建朝[1] 王浩然 席志轩 冯伟 赵琳颍 WANG Chen1 , LIU Jianchao1 , WANG Haoran1 , XI Zhixuan1 , FENG Wei1 , ZHAO Linying2(1. School of Earth Science and Resources, Chang＇ an University, Xi＇an 710054, Shaanxi, China; 2. No. 2 Institute of Geological ＆ Mineral Resources Survey of Henan, Zhengzhou 450001, Henan, Chin)

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]河南省地质矿产勘查开发局第二地质矿产调查院,河南郑州450001

出　　处：《西北地质》2018年第1期13-22,共10页Northwestern Geology

基　　金：中国地质调查局"整装勘查区深部找矿三维预测方法及示范研究"(12120113091400);山东省地质调查项目"山东省三稀矿产资源潜力及找矿方向研究"(SDZS-2016-GTT01)

摘　　要：甘肃金川二矿区镁铁-超镁铁岩体中橄榄石具有明显的矿物定向排列特征。通过对岩体中二辉橄榄岩、斜长二辉橄榄岩及含二辉石橄榄岩的造岩矿物橄榄石进行组构特征研究,发现均表现出"A"型组构特征,Nm[001]表现为在面理上的点极密,表明其滑移方向为[001]。结合Ng[100]、Np[010]组构特征,其滑移面应为(100)和(010),反映低温组构滑移系为(100)[001]或(010)[001],表明二矿区岩体橄榄石形成于地壳浅部低压、低应力状态下。由于二矿区岩体为金川矿床第二期含矿岩浆上侵产物,结合岩体所受的构造应力场的变化特征,可初步认定二矿区岩体中橄榄石定向排列的现象为成矿期构造的反映,且橄榄石光轴发生了自西向东的旋转,这也与李区域组构特征的研究相一致。In No. 2 mining area of the Jinchuan deposit, Gansu province, the olivine from maficultramafic rocks show the characteristics of minerals oriented arrangement. The fabric features of the olivines from lherzolite, plagioclase lherzolite and pyroxene dunite have been studied in this paper. The results show the characteristics of type- ＂A＂ [100] （010） fabric, the Nm [001] is the point maximum of the foliation and the slip direction is [001] . Combined with the fabric characteristics of Ng ;100] and Np ;010], the slip plane should be the （100） and （010）, and this belongs to the low temperature slip system （（100） [-001] or （010） [001]） . All of these characteristics mentioned above indicate that, these rocks may be formed under the shallow crust environment with low pressure and low stress state. The mafic-ultramafic rocks in the No. 2 mining area were served as the products of the crystalline differentiation during the second stage of sulfide-bearing magma ascending in the Jinchuan deposit. Combined with the variation characteristics of tectonic stress field in this deposit, the olivine alignment has reflected the structure of the mineralization period

关 键 词：金川 二矿区 橄榄石 组构特征 应力分析 

分 类 号：P588.12[天文地球—岩石学]