Magnetic Basement Modeling at Karimata Strait Using MagB_Inv

Abstract

Indonesia is a country with abundant natural resources, such as tin, which is associated with granite rocks. Granite can be found under sedimentary rocks as basement rock. The depth of the magnetic basement will provide a value that indicates the location or presence of granite rock. This research is expected to be possible to identify the depth of the magnetic basement in the Karimata Strait area and obtain a relationship between the results of magnetic basement modeling using the MagB_Inv program and the regional geological structure in the Karimata Strait area. Based on magnetic anomaly data used, digitization was carried out to obtain contour maps using ArcMap and gridding using Oasis Montaj. Then do the calculation of the average depth estimate using the Radially Averaged Power Spectrum (RAPS) and magnetic basement modeling using MagB_Inv. Depth values that vary from 3.2 to 6.3 km, with average of 4.5 km, indicate significant undulation in the west-east direction. Meanwhile, in the north-south direction, the depth undulation tends to be less significant. According to geological modeling, there is an indication of a basin known as the Bangka Basin, and the magnetic basement in the study area is granite.