INTERPRETASI STRUKTUR BAWAH PERMUKAAN MENGGUNAKAN METODE MAGNETIK PADA GUNUNG MUDJIL KULON PROGO; SUBSURFACE INTERPRETATION USING GEOMAGNETIC METHOD IN GUNUNG MUDJIL KULON PROGO

Celia, Alfania R, Wahyudi

2016 | Skripsi | FMIPA

Gunung Mudjil is located in the east of Kulon Progo highlands, and is administratively belong to Kalibawang, Kulon Progo, Daerah Istimewa Yogyakarta district. There were some hypothesis about how Gunung Mudjil was formed, either due to Old Andesite Formation landslide or intrusion of Old Andesite Formation. Therefore to answer those hypothesis, magnetic method was used in this study. The field campaign were conducted in six days, from July 29th until August 3rd 2015, covering 2x2 km2 area, with 100 m spacing for each point. Proton Precession Magnetometer Geotron G-5 and Proton Precession Magnetometer Geometric G-856 were used. Firstly, global magnetic Earth correction and daily variance correction were used to get magnetic field anomalies. And then, 200 m upward continuation was performed. Quantitative interpretation was done by magnetic anomaly modelling. The models show that the susceptibility of basement is 0.025 SI, the susceptibility of Nanggulan Formation is 0.007 SI and the Old Andesite Formation susceptibility is 0.017 SI. Gunung Mudjil could be formed by landslide process of the Old Andesite Formation to the west of Gunung Mudjil.

Kata Kunci : Gunung Mudjil; magnetic method; susceptibility; Old Andesite Formation