Sedimentary Facies Feature of Paleogene Lower Ganchaigou Formation in the West Segment,North Edge of Qaidam Basin

Based on description of field outcrop profiles and cores,well drilling and logging and so on,the types of the sedimentary facies and their characteristics of Paleogene Lower Ganchaigou Formation were studied.The research shows that alluvial fan,fan delta,braid river,braided delta and lacustrine facies were present in the formation.There is a set of fan,fan delta,lacustrine facies depositional system in the Eboliang-Lenghu-Qianxi area,and a set of fan,braid river,braided delta,lacustrine facies depositional system in the Mahai-Nanbaxiang area.The sedimentary facies model was established of Low-Ganchaigou Formation.It demonstrates the sedimentary facies distribution more clearly,providing the reliable geological information for the next exploration activity.