Study site administratively located in the village of Besuki, Lumbir district, Banyumas regency, Central Java. Study area is located to the west of the Banyumas regency. Geographically the area of research lies in 108o58’40” E – 109o01’20” E and 7o29’30” S - 7o32’00” S
Geomorphological units of the study area was divided into three units Geomorphology, namely Canduk Homocline Hills Unit, Parungkamal Anticline Hills Unit, and Besuki Alluvial Plain Unit.
Stratigraphy of the study area is divided into four units based on an unofficial unit. Sequence of lithologies from the old to the young age are : Marl Unit (Pemali Formation), Sandstone-Mudstone Unit (Sandstone Member of
Halang Formation). Mudstone-Sandstone Unit (Halang Formation). Alluvial sediment Units deposited above the unconformity lithologies older age and the deposition process has continued until today.
Structural Geology of the study area is consist of Besuki Anticline Fold Structural, Karanggayam Sincline Fold Structural, and Randegan Reverse Right Slip Fault Structural.
Pemali Formation in the study area which is dominated by marl unit of material is fine clastic sediments were deposited by the current mechanism turbidit and deposited on lower fan, which is compiled by marl, sandstone, and limestone. Age of Pemali Formation older than the Halang Formation is in accordance with Late Miocene based on Sumarso and Suparyono (1974), also Casdira (2007) that estimated as Upper Pemali Formation. Not consistent with Lunt (2008) of Early Pliocene age - Pliestosen. This study indicates that stratigraphic contact between Pemali Formation and Halang Formation above is gradually contact.