Identifikasi Struktur Tektonik Sistem Geothermal Non-Vulkanik Daerah Nyelanding dan Permis Bangka Selatan Menggunakan Metode Gravity

Abstract

Non-volcanic geothermal is a heat system that is not related to volcanism such as in Nyelanding and Permis areas. In previous studies, hot springs in the Nyelanding area were spread from West to Northeast, with the constituent rocks of sandstone, dry gravel and granite. In the Permis area, the manifestation is influenced by shear faults trending Northwest to Southeast and the geothermal source is granite. Therefore, this study was conducted to determine the strenght of local tectonic structures using the gravity method. The data used in this study are the FAA (Free Air Anomaly) and topography data obtained through the TOPEX website. The gravity anomaly is obtained by performing spectral analysis using the Fourier Transform and moving average filter. 2D modeling is performed using inverse modeling with the smoothness constraint equation. The result of this research is that the Permis and Nyelanding geothermal systems are controlled by local tectonic structures in the Northwest and Southeast of the study area, in the form of fractures (possibly faults) with a Northeast – Southwest direction

Analisis Anomali Gravity Daerah Panas Bumi Non-Vulkanik Di Bangka Tengah (Studi Kasus Panas Bumi Terak dan Keretak)

“…Anomali regional disebabkan oleh perbedaan densitas batuan pada daerah yang lebih dalam [6]. Nilai anomali tinggi dimungkinkan adanya batuan yang memiliki densitas dan ketebalan yang tinggi [19]. Nilai anomali sedang dimungkinkan adanya batuan yang memiliki densitas sedang dan kedalaman yang tinggi sedangkan nilai anomali rendah memiliki densitas rendah dan kedalaman yang tinggi.…”

“…Sebaran anomali residual dapat dilihat pada gambar 3(b). Nilai sebaran anomali residual berbeda-beda disebabkan adanya densitas batuan yang berbeda [19]. Berdasarkan gambar 3, nilai anomali residual berkisar antara 7 mGal sampai 29 mGal (warna unggu sampai orange).…”