IDENTIFICATION OF SUBSURFACE GEOLOGICAL STRUCTURE IN KARANGSAMBUNG-KEBUMEN USING GRAVITY METHOD
<p align="justify">Geological characteristic of Indonesia is unique because of tectonic boundary among three major plates. One of subduction zone in Cretaceous Period is located at Karangsambung in Kebumen Regency, Central Java. Karangsambung is the locations of subduction zone betwe...
Saved in:
| Main Author: | |
|---|---|
| Format: | Final Project |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/27261 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | <p align="justify">Geological characteristic of Indonesia is unique because of tectonic boundary among three major plates. One of subduction zone in Cretaceous Period is located at Karangsambung in Kebumen Regency, Central Java. Karangsambung is the locations of subduction zone between Eurasian Plate and Indo-Australian Plate. This type of subduction is convergent resulting in the mix of oceanic base rock and sedimentary rocks which is deposited in continental crust basin. The mixing rocks were lift up to the surface in Karangsambung, thus the area contains of variety of rocks; igneous rocks, sedimentary rocks and metamorphic rocks. Since combination of rocks in Karangsambung came from different sources and random distribution, therefore, this area seems difficult to be mapped. This uniqueness of Karangsambung area encourages both local and international geoscientists to conduct fieldworks in order to map and to discover the real geological subsurface condition. In this research, gravity method is used to analyse subsurface geological structure and the map of Karangsambung area. Started with finding gravity anomaly map. Then, this map is digitized for further processing data. This method can be conducted with separating the regional anomaly and residual anomaly from a complete Bouguer anomaly map by moving average and spectrum analyses method to obtained windowing filter. Then SVD is conducted to analyze geological structure around research area. Followed by 2.5D forward modelling with geological data support. The interpretation result of geological subsurface model could describe the relation between sedimentary rocks of Karangsambung Formation, Totogan Formation, Waturanda Formation, Penosogan Formation, Breccias Group of Halang Formation, Halang Formation, and alluvium which is deposited in Karangsambung and Luk Ulo Melange Complex rocks. <p align="justify"> |
|---|