对藏北嘎色地区沙木罗组的新认识

New explanation of the Shamuluo Formation in the Gase region,northern Xizang

笔者在西藏班公错-怒江结合带中段南缘嘎色地区的一套缺少化石依据的地层中,发现有孔虫Mesorbitolinasp.等化石,地层时代确定为晚侏罗世—早白垩世,层位应归属沙木罗组上部。该套地层地质时代的确定,对研究沙木罗组的沉积相,重塑古地理环境有十分重要意义。

The foraminifera Mesorbitolina sp. occurs in the unfossiliferous strata in the Gase region, northern Xizang The stratigraphic ages are traced back to the Late jurassic - Early Cretaceous. The strata should be assigned to the upper purt of the Shamuluo Fonnation. The timing of the strata is significant to the sedimentary facies analysis and palaeogeographic reconstruction of the Shamuluo Formation.