投稿时间：2011-05-24
修订日期：2012-01-06
中文摘要:角岩在西藏冈底斯成矿带内的甲玛、驱龙、劣布、雄村、则莫多拉铜矿和弄如日金矿等矿床中均有产出,但角岩的特征及与成矿的关系却不相同。选择拉萨地区墨竹工卡县甲玛铜多金属矿床和日喀则地区谢通门县雄村铜金矿床的角岩作为对比研究的对象,从地质背景、角岩的原岩、化学成分、矿物组成、空间分布、形成次序和矿化特点等方面进行了两者的对比,认为甲玛矿床中由砂岩、板岩热变质形成的角岩,形成于成矿前,作为矽卡岩型矿体的顶板,起到隔挡成矿流体运移的作用,有利于成矿,且在角岩中亦形成了具有经济价值的矿化。在找矿过程中亦可作为找矿线索,大规模的角岩盖层指示了深部岩体的存在,其厚度和矿化变化可为判断岩体中心提供依据。雄村矿床中的角岩由成矿后喜马拉雅期黑云母花岗闪长岩侵入凝灰岩而引起的热变质所形成,对已形成的矿体影响不大;在找矿过程中,可利用地面磁测获得铜矿体及角岩等围岩的磁场强度,有助于确定矿化体的位置。
Abstract:Hornfels occurs widely in such copper deposits and gold deposits of the Gangdise metallogenic belt in Tibet as Jiama, Qulong, Liebu, Xiongcun, Zemoduola and Nongruri. However, its features and relationship with mineralization vary remarkably. The Jiama copper polymetallic deposit in Maizhokunggar County of Lhasa and the Xiongcun copper and gold deposit in Xaitongmoin County of Xigaze were chosen as the objects for comparative study of such aspects as geological setting, original rock, chemical component, mineral assemblage, spatial distribution, formation sequence and mineralization. Hornfels from Jiama was formed from sandstone and slate through thermal metamorphism before mineralization. As the hanging wall of skarn type ore body, hornfels obstructed the movement of ore-forming fluid, which was favorable for mineralization in the skarn, and finally resulted in the mineralization in the hornfels itself. In ore prospecting, extensive cover of hornfels suggests the existence of huge heat source in the deep, and the change of its thickness and mineralization can provide useful information concerning the central position of the deep rock body. Hornfels in Xiongcun was formed through the thermal metamorphism caused by the intrusion of Himalayan biotite granodiorite into tuff after mineralization, thus failed to affect the mineralization. In the prospecting process, the ground magnetic survey of copper ore body and wall rock including hornfels will be useful in determining the location of mineralized body in the depth.
文章编号：
中图分类号：P618.41
文献标志码：
基金项目:本文得到国家973课题(编号:2011CB403103)、中央公益性行业科研专项课题(编号:200911007-02)及地质大调查项目(编号:20089947;1212010633903)的联合资助
引用文本：
应立娟,唐菊兴,黄勇.2012.西藏甲玛和雄村铜矿区角岩的对比研究[J].矿床地质,31(2):380~390YING LiJuan,TANG JuXing,HUANG Yong.2012.Hornfels comparative study of Jiama and Xiongcun copper deposits, Tibet[J].Mineral Deposits31(2):380~390
图/表
