摘要
素有"金三角"之称的右江盆地广泛发育卡林型金矿,其成因是否与岩浆活动有关颇有争议。本文以云南富宁地区的者桑卡林型金矿床和该区出露的基性岩为研究对象,分别确定了卡林型金矿床和基性岩的年龄。研究表明,矿床中与载金矿物黄铁矿和毒砂共生的热液蚀变成因绢云母的Ar-Ar坪年龄为215.3±1.9Ma,该区晚期基性岩中锆石的U-Pb年龄为215±5Ma,成岩成矿时代高度一致。在此基础上,本文提出了该矿床的成矿动力学模式:伴随古特提斯洋的闭合,在印支运动后碰撞伸展背景下,形成了富宁地区215±5Ma的基性岩。者桑金矿床分布区的深部可能存在该时期的隐伏岩体,深部岩浆活动驱动主要为大气降水成因的流体浸出地层中的金、砷和锑等成矿元素形成了者桑金矿床。
The Dian-Qian-Gui region, commonly referred as the 'Golden Triangle' in SW China, hosts many Carlin-type gold deposits. Previously, the relationship between gold mineralization and magmatism has not been well constrained. This paper reports a geochronological study on the Zhesang Carlin-type gold deposit and mafic intrusion in the Funing County of Yunnan Province, China. Dating by 40Ar/39Ar of hydrothermal sericite grains collected from altered rocks near auriferous quartz veins at Zhesang gold deposit yielded a plateau age of 215.3 ± 1.9Ma, which is highly consistent with zircon U-Pb age (215 ±5Ma) of the marie rock in a nearby area. It is inferred that there might exist contemporaneous buried intrusions in the Zhesang deposit. The deep-seated magma, resulted from the post-collision of the Indochina Block with the South China Block, triggered fluids of possibly meteoric origin to circulate and leach out ore-forming elements from sedimentary rocks to form the Zhesang Carlin-type gold deposit.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2016年第11期3331-3342,共12页
Acta Petrologica Sinica
基金
国家重点基础研究发展规划项目(2014CB440906)
国家自然科学基金项目(41230316、41563004)
有色及贵金属隐伏矿床勘查教育部工程研究中心委托项目(GCZX003)联合资助