STRATIGRAPHIC AND FACIES STUDY OF BATURAJA AREA, OGAN KOMERING ULU REGENCY, SUMATRA SELATAN PROVINCE

• Main Author: Edi Sunyoto, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/70195
• Institution: Institut Teknologi Bandung

Facies and stratigraphic studies are the studies about changes in depositional environment at spatial, sequence, and time scales, which can then be used as analogoue model to subsurface conditions. In contrast to rock core data, outcrops have better aspects of spatial variation that can be observed. Outcrops can be used as analogoue model to subsurface conditions, therefore facies and stratigraphic analysis of outcrops needs to be carried out to reduce subsurface uncertainty and risk of subsurface interpretation. Stratigraphic analysis method in this study are performed by field observations, measuring stratigraphic sections, petrographic observations of rock samples, and microfossil analysis. The results of the analysis of all these components are combined in a stratigraphic column. The results of stratigraphic cross-sectional measurements, stratigraphic column, hand specimen and thin sections analysis show that the research trajectory consists of the Lemat Formation and the Talangakar Formation which is composed of 14 lithofacies and Baturaja Formation which consists of 11 lithofacies. Research trajectory is divided into 5 architectural facies in Lemat Formation and Talangakar Formation consisting of: Root Alluvial Fan, Massive Layers of Middle Alluvial Fan, Peat Bog of Middle Alluvial Fan, Deep Gravel Bed Braided, Gravel Bed Braided with Sediment Gravity Flow Deposits, and 5 architectural facies in the Baturaja Formation consisting of Carbonate Platform Interior (AA), Carbonate Platform Margin Sand Shoals (AB), Carbonate Platform Margin Reef (AC), Carbonate Foreslope (AD), Basin Margin Carbonate (B) Paleocurrents analysis on Talangakar Formation shows two different current directions, south and east. Benthic foraminifera on Baturaja Formation analysis shows middle neritic bathymetry depth on Basin Margin Carbonate - Foreslope architectural facies and shows inner neritic depth on Platform Margin Reef - Platform Interior architectural facies. Planktonic foraminifera analysis showed that biozonation age was N5 and/or older in Basin Margin Carbonate architectural facies and N6 and/or younger in the Foreslope - Platform Interior architectural facies.