Tectonostratigraphy of Ciletuh Area, Ciemas District, Sukabumi Residence, West Java Based on Surface Geological Mapping

Tectonostratigraphy of Ciletuh Area, Ciemas District, Sukabumi Residence, West Java Based on Surface Geological Mapping

Ciria Humanis Brilian

Email : ciriahumanis@yahoo.co.id

Universitas Padjadjaran

 

ABSTRACT

 

A tectonostratigraphy study is conducted in the Ciletuh area more precisely in the Kecamatan Ciemas, Kabupaten Sukabumi, West Java. This location is part of Digital Topographic Map of Indonesia (Bakosurtanal) Lembar Ciwaru (1108-642) and Lembar Ciemas (1208-431). Geographically is located between S 7 ° 13 ‘4″ to 7 ° 8′ 44″  and E 106 ° 26 ’13 “- 106 ° 31’ 38”. Based on Jampang and Balekambang Geological Map (Sukamto, 1975), the study area consists of Jampang Formation and Bayah Formation.

The aim of this study was to determine the condition of the geological structure of the area in order to know tectonic processes associated with depositional of rocks units that formed in the study area based on surface mapping that includes stratigraphic analysis, geological structure  analysis and analysis of the literature data for comparison.

The study area is composed of three lithological units from the oldest are quartz sandstone unit (Tebpk), sandstone unit (TMBP) and sediment Alluvial (Qa). There are three periods of tectonic occurred in the area of research that period of compressional tectonic Northeast – Southwest Oligocene affecting quartz sandstone unit and forms paleohigh. The second, period of compressional tectonic Northeast – Southwest Miocene affecting sandstone unit and forms folds and faults. The last, period of compressional tectonic Northwest – Southeast Pliocene forms the horizontal faults and landslide that forms a horseshoe morphology commonly called Amphitheatre Ciletuh.