甘孜-理塘金成矿带构造活动的磷灰石裂变径迹年代学制约  

Apatite fission track constrains on tectonic activities in Ganzi-Litang gold belt,Qinghai-Tibet Plateau

作　　者：张丽婷[1] 袁万明[1] 李娜 郇伟静 张静[1] 王庆飞[1] 龚庆杰[1] 

机构地区：[1]中国地质大学,北京100083 [2]中国光华科技基金会,北京100009 [3]中铁资源集团有限公司,北京100039

出　　处：《岩石学报》2015年第11期3353-3362,共10页Acta Petrologica Sinica

基　　金：国家重点基础研究发展规划项目(2015CB452606);中国地质调查局研究项目(1212011121260);国家自然科学基金项目(41172008;40872141)联合资助

摘　　要：甘孜-理塘金矿带形成于三江特提斯巨型造山带中,是三江金矿床的典型代表,具有长期活动的特点,形成了复杂的构造系统。多期构造活动有助于区内深源分散金元素的活化、迁移和富集沉淀,为成矿提供了十分有利的条件。本文介绍了甘孜-理塘金矿带错阿、西冲农、嘎拉、雄龙西和曲开隆洼这5个典型矿区的矿床特征,各矿区共计获得的9个磷灰石裂变径迹年龄值,总体显示为92~88Ma,34~26Ma,17~15Ma和8.1Ma共4个年龄组。4个年龄组均较好的体现了不同地质时期的构造活动及其时限,不仅为该地区提供新的年代学数据,也为该地区的构造演化提供了新证据。通过定量计算,得到本区不同地段的隆升幅度和隆升速率。隆升幅度分为3个量级,即5405m,6023~6272m和6519~6576m。隆升速率变化于0.07~0.81mm/a之间,大致可以分为4个量级,即0.07mm/a,0.18~0.24mm/a,0.32~0.43mm/a和0.81mm/a。两者均具有不同的量级,显示本区差异隆升的特点。Ganzi-Litang gold belt belongs to the Sanjiang Tethyan orogenic belt and it is a typical representative of gold mineralization. The Ganzi-Litang fault has experienced multiple tectonic activities that are conducive to the gold element migration and favorable for mineralization. In this paper,a total of five typical deposits,Cuo＇a,Xichongnong,Gala,Xionglongxi and Qukailongwa,were introduced. The nine apatite fission track ages are achieved and show four groups of 92 ~ 88 Ma,34 ~ 26 Ma,17 ~ 15 Ma and8. 1Ma. According to the sample result,the uplift amplitude and the uplift rate are calculated quantatively,revealing different orders of magnitude and the uneven uplift. The uplift amplitude is divided into three orders of magnitude,which is 5405 m,6023 ~ 6272 m and6519 ~ 6576 m. The uplift rate is divided into four orders of magnitude,which is 0. 07 mm / a,0. 18 ~ 0. 24 mm / a,0. 32 ~ 0. 43 mm / a and 0. 81 mm / a. The four age groups accord better with tectonic-magmatic activity and their developing periods. The new geochronological data and new evidences for the tectonic evolution of Ganzi-Litang gold belt are presented.

关 键 词：构造活动 裂变径迹 磷灰石 甘孜理塘金矿带 青藏高原 

分 类 号：P542[天文地球—构造地质学] P618.51[天文地球—地质学]