康滇地区位于我国西南腹地,北起康定,南迄云南元江,西以玉龙山—锦屏山为界,东至昭觉—东川,南北长约500km,东西宽200km,在近10万km2区域内断续出露了大量元古宙基底地层,北边有康定群、登相营群,中部为河口群、会理群、东川群、汤丹群和苴林群,南部包括大红山群、昆阳群等。上述基底地层中,以北部的康定群和中部的苴林群变质程度最高,且早期获得的康定群同位素年龄大多集中在晚太古代和古元古代早期(马杏垣等,1980;袁海华等,1986),因此康定群和苴林群一直以来被认为是康滇地区最古老的基底地层。 The Kangdian region is located in the hinterland of China’s southwest. It is composed of Kangding in the north, Yuanjiang in Yunnan in the south, Yulongshan-Jinping Mountain in the west, Zhaojue-Dongchuan in the east, 500km long in the north and south and 200km wide in the east and west in nearly 100,000 km2 There are a large number of Proterozoic basement strata exposed intermittently. There are Kangding Group and Dengxiangying Group to the north, Hekou Group, Huili Group, Dongchuan Group, Tangdan Group and Zhelin Group in the middle part, Dahongshan Group and Kunming Group in the south Yang group and so on. Among the above basement strata, the Kangding Group in the north and the Gaolin Group in the middle have the highest degree of metamorphism, and most of the earliest Kangding Group isotopic ages are concentrated in the Late Archean and Early Paleoproterozoic (Ma Xingyuan et al., 1980; Yuan et al., 1986) , So Kangding Group and Zhelin Group have always been considered as the oldest basal strata in the Kandian region.