太行山南段铜矿成矿时代厘定及成矿意义

发布时间：2018-05-27 07:32

本文选题：铜矿 + 成矿时代　；参考：《地质学报》2017年12期

【摘要】：太行山南段井陉-内丘一带是河北省重要的铜矿远景区,区内成矿条件优越。已有研究资料多将该区铜矿类型、成矿条件等与山西中条山铜矿富集区进行类比。由于缺少对铜的成矿时代的精确限定,致使无法对区内铜矿床的形成过程及成因进行较为准确的分析,制约着区域铜矿成因类型对比及找矿勘查工作部署。本文以区内桃园铜矿床及酸枣坪、虎寨口、鹿峪和方垴等四个铜矿化点为研究对象,采用Rb-Sr法测试分析了上述铜矿床及矿化点的矿石硫化物。测试结果显示,桃园铜矿不同硫化物对Rb-Sr等时线年龄在1829.6~1840Ma之间,酸枣坪铜矿点的形成时代为1830.7±5.2Ma,虎寨口铜矿点的形成时代为1844.3±5.9Ma。上述三个铜矿床(点)矿石硫化物Rb-Sr等时线年龄测试结果表明,在古元古代晚期区内有一次较为强烈的铜矿成矿作用,成矿时限在1830~1844Ma之间。而方垴和鹿峪两个铜矿化点矿石硫化物测年结果与上述三个铜矿床(点)形成时间有较大差异,Rb-Sr等时线测年结果分别为1402±23Ma和1376±37Ma,说明在中元古代长城纪末期区内仍有一次铜矿化作用发生。结合华北地台构造演化过程,太行山南段古元古代晚期第一次铜矿化与山西中条山胡-篦型铜矿形成时代接近,铜矿床的形成与吕梁运动关系密切。由于太行山南段铜矿(点)分布区地处陆内构造环境的晋豫裂陷带,而山西中条山铜矿富集区处于秦岭-大别活动带的北缘的"秦岭古洋"壳向华北地台俯冲环境,构造环境差异可能导致两区在铜矿形成潜力及规模上存在一定差异。与区内第一次铜矿化作用相比,发生在中元古代长城纪末期的第二期铜矿化在成矿规模及强度上均较弱,其成矿动力学机制有待进一步分析确定。
[Abstract]:Jingxing-Neiqiu area in the southern section of Taihang Mountain is an important copper mine area in Hebei Province. Most of the previous studies have compared the copper deposit types and metallogenic conditions with the rich areas of Zhongtiaoshan Copper Mine in Shanxi Province. Due to the lack of precise definition of the metallogenic age of copper, it is impossible to make a more accurate analysis of the formation process and genesis of copper deposits in the region, which restricts the comparison of the genetic types of regional copper deposits and the arrangement of prospecting and exploration. Taking the Taoyuan copper deposit and four copper mineralization sites such as Suanzaoping, Huzhaikou, Luyu and Fangnao as the research objects, the ore sulfides of the above copper deposits and their mineralization sites have been measured and analyzed by Rb-Sr method. The results show that the Rb-Sr isochron age of different sulfides in Taoyuan copper mine is between 1829.6~1840Ma, the age of formation of the site is 1830.7 卤5.2Maand that of Huzhaikou copper deposit is 1844.3 卤5.9Ma. The results of Rb-Sr isochron dating of ore sulphide in the three copper deposits (points) indicated that there was a strong mineralization of copper deposits in the late Paleoproterozoic area, and the metallogenic time was between 1830~1844Ma. The results of ore sulphide dating at Fangnao and Luyu copper mineralization sites are quite different from those of the three copper deposits (points) mentioned above. The results of Rb-Sr isochron dating are 1402 卤23Ma and 1376 卤37Marespectively, indicating that in the late the Great Wall area of the Mesoproterozoic era, there is still a significant difference between the results of Rb-Sr isochron dating and those of the three copper deposits. There was a copper mineralization. Combined with the tectonic evolution of the North China platform, the first copper mineralization in the late Gu Yuan in the southern Taihang Mountains is close to the formation age of Hu-Be copper deposit in Zhongtiaoshan, Shanxi, and the formation of the copper deposit is closely related to the Lv Liang movement. Because the distribution area of copper deposits (points) in the southern Taihang Mountains is located in the Jinyu rift belt in the continental tectonic environment, and the rich copper deposit area of Zhongtiaoshan Copper Mine in Shanxi Province is located in the "Qinling paleo-oceanic" crust subducting to the North China platform in the northern margin of the Qinling-Dabie active belt, The difference of tectonic environment may lead to some differences in the formation potential and scale of copper deposits between the two regions. Compared with the first copper mineralization in the region, the second stage copper mineralization occurred in the late the Great Wall period of Mesoproterozoic is weaker in the scale and intensity of mineralization, and the dynamic mechanism of mineralization needs further analysis and determination.
【作者单位】：河北地质大学;河北省地矿局探矿技术研究院;南京大学;
【基金】：河北省国土资源厅基金项目(编号2012055548)和(编号2013045655)联合资助的成果
【分类号】：P618.41

【相似文献】