Integrated Geomorphological, Stratigraphic and Structural Controls on Landscape Evolution of the North Serayu Zone, Central Java, Indonesia

Abstract

Geological mapping is essential for understanding the relationships among geomorphology, stratigraphy, lithology, and structural geology, which collectively control landscape evolution. This study aims to characterize the geomorphology, stratigraphy, structural geology, and geological evolution of the Rembang area and its surroundings in the North Serayu Zone, Central Java, Indonesia. The research employed an integrated qualitative and quantitative geological mapping approach combining field investigations, geomorphological analysis, stratigraphic interpretation, structural measurements, petrographic observations, Geographic Information System (GIS), and Digital Elevation Model (DEM-SRTM) analysis over a 16 km² study area. The results identified two principal geomorphological units, namely denudational hills (55%) and denudational plains (45%), characterized by dendritic to sub-dendritic drainage patterns controlled by lithological resistance and tectonic structures. Stratigraphically, the area consists of three major lithological units: Andesite Intrusion, Andesite Breccia, and Quaternary Alluvial Deposits, representing successive magmatic, volcanic, and surface depositional processes. Structural analysis revealed a dominant northwest-southeast tectonic trend expressed by joints and a dextral normal fault that significantly controls ridge alignment, valley orientation, and drainage development. Petrographic observations indicate porphyritic to aphanitic andesite composed predominantly of plagioclase, quartz, and biotite, confirming shallow intrusive magmatism. The reconstructed geological evolution suggests that the area experienced Pliocene magmatism, followed by Pleistocene volcanism, subsequent tectonic deformation, and ongoing Holocene denudation and fluvial sedimentation. These findings demonstrate that the present landscape represents the combined effects of lithological resistance, tectonic deformation, and prolonged denudational processes, providing valuable insights for regional geological interpretation, geohazard assessment, land-use planning, and geotourism development.