摘要:The Halang formation consists of sandstones, mudstones and breccias. Facies study on the Halang Formation in Cibalung Area, Cimanggu District, Cilacap Regency, and Central Java has been carried out based on the detailed stratigraphic measurements along the Cikawung and Cimindi River. The Halang Formation can be divided into 7 lithofacies namely: A1, B1, B2, C2, D2, E2 and F2. The facies associations suggest that there are sub-depositional environment for the Halang Formation, which are slope, inner fan, middle fan and outer fan of the deep marine fan. Changes in depositional environment suggest a prominent influence from the sea level change during sedimentation that may also cause by the volcanic activity.