摘要
The evolution of Altyn Fault holds a key link in understanding the formation process of Tibet Plateau. The sedimentary and tectonic study of seismic sections,strata isopach maps and sedimentary facies maps of NW Qaidam Basin reveals the initial uplifting related with Altyn Fault at the Late Eocene,which led to the formation of the growth strata at the NW margin of Qaidam Basin. While in the map view,these NWW-SEE trending uplift sintersect with Altyn Fault by an angle of ~ 30° and induce marginal sedimentary environment such as alluvial fan etc. Based on these observations,we conclude the initial development of Altyn Fault started at the Late Eocene,which may form a ductile sinistral shear zone in the deep and as a result a left-ordered echelon folding zone on the surface for accommodating the displacement.