Geological Mapping and Reconstruction of the Geological Evolution in the Karanganyar Area, Purwanegara District, Banjarnegara, Central Java

Abstract

The Karanganyar area, Purwanegara District, Banjarnegara Regency, Central Java, forms part of the South Serayu Range, characterized by a complex geological setting resulting from the interaction of carbonate sedimentation, volcanic activity, tectonic uplift, and denudation. This study aims to reconstruct the geological evolution of the research area through geological mapping integrated with geomorphological, lithostratigraphic, petrographic, and structural geology analyses.  

The results indicate that the area is dominated by the Karanganyar Denudational Hill Unit with  lithostratigraphy comprising a Crystalline Limestone Unit, a Monomict Breccia Unit, and a Polymict Breccia Unit. Geological structures are not significantly developed at the mapping scale. The geological evolution reconstruction reveals that the area developed through four main stages: carbonate sedimentation in a shallow marine environment, followed by volcanic activity, regional uplift, and ongoing weathering and denudation that shaped the current landscape. This study presents a local geological evolution model that enhances the understanding of the geological development of the Karanganyar area as part of the South Serayu Range.