GEOLOGY AND KINEMATIC ANALYSIS OF BALANTAK FAULT, RAU AREA, BANGGAI REGENCY, CENTRAL SULAWESI

• Main Author: Ghiffari, Guntur
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/43848
• Institution: Institut Teknologi Bandung

The study area is 100 km2 large located in Balantak and South Balantak Sub-district, Banggai Regency, Central Sulawesi Province. The area coordinate is UTM 535000 mE – 545000 mE and 9898000 mN – 9908000 mN (UTM WGS 84, Zone 51S). This research’s aim to understand the geological conditions of Rau area and to analyze Balantak's Fault kinematic using fault slip data to identify its deformation and its correlation to other developed structures within the study area. The methods of this study are direct field observation of which later conducted petrography analysis, micropaleontology analysis, dan structural kinematic analysis. The geological unit divided into seven lithological units which comprise from the oldest into, Ultramafic Rocks Unit, Grainstone Unit, Rudstone Unit, Conglomerate Unit, Boundstone Unit, Sandstone Unit and Alluvial Unit. Almost all of the ultramafic rocks in the area had been severely serpentinized, consist of Gabbro and Serpentinized Peridotite. The limestone units consist of wackestone, packestone, grainstone, rudstone, floatstone, and boundstone, Conglomerate unit is poorly sorted, well rounded, mud-supported, and unconsolidated carbonate clay matrix, consist of serpentinized peridotite, gabbro and a few limestones. Sandstone unit is dark colored, well sorted, well rounded, grains-supported, consist of serpentinized peridotite, gabbro, and a few limestones. The age of the lithological unit in the area ranges from Cretaceous to Recent. Kinematic analysis based on 5 station of fault slip data along the Balantak Fault resulting in similar results. The strike orientation of Balantak Fault ranging from N278oE to N297oE, with shortening axis (P) ranging from N325oE to N344oE and extension axis (T) ranging from N235oE - N253oE showing that this fault is a dextral strike-slip fault. The folds and thrust shown in the study area could not developed from Balantak Fault. Based on regional study, the folds and thrust was formed by the Batui Thrust on the far west then rotated by Balantak Fault on Late Miocene – Pliocene