分布于四川西北部若尔盖地区秦岭褶皱带西段的白依沟群,由一套浅变质的陆源碎屑及火山质碎屑岩及其过渡类型的岩石组成。白依沟群过去认为是奥陶-志留纪的沉积。自1982年在西秦岭开展1:5万区调和科研工作以来,通过岩性,岩相以及区域地层对比,笔者认为此套岩系与川西下震旦统苏雄组和开建桥组相当.因此,首次提出秦岭西段有早震旦世陆相沉积,证实了当时甘孜松潘一带为一古陆。 The Baiyi gully group distributed in the western part of the Qinling fold belt in the Zoige area in northwestern Sichuan consists of a series of metamorphic terrigenous clastics and volcaniclastic clastics and their transitional types of rocks. In the past, the Baihe Gully was considered to be Ordovician-Silurian sediments. Since the 1: 50000 regional reconciliation and scientific research carried out in West Qinling in 1982, the authors believe that this series of rocks are comparable to the Lower Sinian Suxiong Formation and Kaijianqiao Formation in western Sichuan through lithology, lithofacies and regional stratigraphy. Therefore, for the first time, there is an early Sinian terrestrial deposition in the western part of Qinling Mountains, confirming that the area of ​​Ganzi Songpan was an ancient land.