摘要
近年来在绿汁江断裂以东元江县岔河一带发现一块面积较大的中-深变质岩系。其岩性主要是变粒岩、混合岩、石英岩、片岩、大理岩和变钠质火山岩,变质程度已达高绿片岩相到角闪岩相。原岩应是海相钠质火山岩。它可以和下元古界大红山群对比,相当于大红山群底巴都组二段到曼岗河组一段。在底巴都组混合岩中测得(Rb—Sr全岩等时线)同位素年龄为1777Ma。区内已找到中型铜矿床并伴有金、铀矿产。
A block of metamorphic rocks of middle to high-grade with rather large area, east of the Luzhijiang Fault, Yuanjiang County, was discovered. in re-cent years. It is composed mainly of granulitite, migmatite, quartzite, schist, marble and metamorphosed sodic volcanic rock. Its metamorphic degree rea-ched high greenschist facies to amphibolite facies. The protolith was sodic volcanic-sedimentary rock series of marine facies. It could be compared with the Dahqngshan Group of Early Proterozoic Era. It corresponds to the strata from the 2th member of the Dibadu For-mation up to the Ith member of the Manganghe Formation within the Dahon-gshan Group. Rb-Sr(whole rock, isochron)age of migmatite of the Dibadu Formation is 1777 Ma. Rich, middle-size deposit of copper, accompanied with gold and uranium has been found in this district.
出处
《云南地质》
1993年第1期21-30,共10页
Yunnan Geology
