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本文描述了1:20万贡岭幅水洛地区新发现的前寒武纪地层,划分为前震旦系(称恰斯群,包括五个岩组)和震旦系(上统)。前者为优地槽型的基底变质岩系,厚度四千余m,时代属元古代;后者为碎屑岩和碳酸盐岩,是地台型的沉积盖层,富含蓝藻等类化石,厚度千余m,时代属晚震旦世;两者呈角度不整合接触。水洛地区与毗邻扬子地台前寒武系具有相似的特征,该区是从扬子地台分离出来的块体,变成为松潘-甘孜印支褶皱系的组成部分。
This paper describes the newly discovered Precambrian strata in the Shui-Luo area of 1: 200000 Gongling Shovel and is divided into the Pre-Sinian system (known as the Qiaosu Group, including the Wugeyan Formation) and the Sinian System (above). The former is a well-trough basement metamorphic rock system with a thickness of more than 4000 m, belonging to the Proterozoic era. The latter is clastic rocks and carbonate rocks, and is a platform-type sedimentary cover that is rich in cyanobacteria and other fossils , The thickness of more than a thousand m, the age is late Sinian; the two are not the point of contact angle integration. The Shui Luo area has similar features to the Precambrian adjacent to the Yangtze platform, which is a block isolated from the Yangtze platform and is part of the Songpan-Ganzi Indosinian fold system.