A review on the chronology of micro-disseminated gold deposits in Yunnan-Guizhou-Guangxi triangle area,southwestern China

Many researchers have studied the chronology on the micro-disseminated gold deposits in Yunnan-Guizhou-Guangxi triangle area in southwest China in the past ten years.Reported dating methods comprise Rb-Sr dating on alteration minerals and fluid inclusions,Pb-Pb dating of sulphide,and fission-track dating of quartz.The ages reported range from 276 Ma to as young as 82 Ma,and fall into three groups,i.e.276~259 Ma,206 Ma,and 157~82 Ma.Dating methods and ages reported are analyzecl and compared.The relationship between these ages reported and corresponding tectonic-thermal events are discusseol in this paper.It is considered that Permian basalt erupted during the development of the Youjiang Late Paleozoic basin providing partly Au,and that large scale lithospheric extension and related magmatic activity in 110~80 Ma in south China are the dynamic setting for the large scale metallogenesis of micro-disseminated gold deposits in Yunnan-Guizhou-Guangxi triangle area,part of the south China metallogenic province.The high precision dating methods,such as,Re-Os dating of sulphide and ~(40)Ar-~(39)Ar dating of sericites are proposed to date this type of gold deposits.