Lineament analysis of digital elevation model to identification of geological structure in Northern Manna Sub-Basin, Bengkulu

Abstract

Digital Elevation Model (DEM) is a representation of the actual landform based on elevation. DEM is part of the technological sophistication that is very helpful in planning, mapping, and surveying. This study applies DEM, which is constructed from DEMNAS, focusing on DEM optimization for geological structures identification.The applied method is ellipsoid stress model analysis approach to determine the type of structure. The scope of this study is located in North Manna Sub-Basin, tectonically is a basin that formed on Paleogen by an extensional force that forms half-graben along the Bengkulu Shelf. Interpretation of DEM in the study area showed the existence of 10 lineament patterns of NE-SW and five NNE-SSW patterns, controlled by normal fault, nine lineament patterns of NW-SE and six WNW-ESE patterns, controlled by a thrust fault and fold. Field observation using direct measurement method obtained by four faults with NE-SW and NNE-SSW pattern, one fault and four folds with NW-SE pattern,three faults and two folds with WNW-ESE trending pattern. This indicates that the accuracy level of DEM in the study area reaches 90%. The geological structure that is still active, certainly requires special attention in building construction.