PEMODELAN BATUAN BAWAH PERMUKAAN SECARA DUA DIMENSI MENGGUNAKAN DATA ANOMALI MAGNETIK DI MIOMAFO BARAT KABUPATEN TIMOR TENGAH UTARA

Abstract

Abstrak

Penelitian tentang pemodelan batuan bawah permukaan secara dua dimensi menggunakan data anomali magnetik ini dilaksanakan di Miomafo Barat Kabupaten Timor Tengah Utara yang bertujuan untuk mengetahui perlapisan batuan dan sebarannya. Pada penelitian ini, data anomali magnetik diperoleh dari Proton Precession Magnetometer (PPM) tipe GSM–19T, dimana data tersebut berupa medan magnet total dan variasi harian. Interpretasi kualitatif terhadap hasil penelitian menunjukkan adanya anomali rendah, sedang dan tinggi sedangkan interpretasi kuantitatifnya memberikan dugaan adanya batu pasir, lempung, batu gamping dan batu ultrabasa sebagai penyusun perlapisan batuan bawah permukaan. Batu pasir dan lempung diduga tersebar setempat-setempat di sekitar arah barat laut, tenggara, timur, selatan barat daya dan barat daya. Sementara, batu gamping diduga memiliki arah sebaran setempat-setempat pada arah sekitar barat laut, utara, timur, Timur laut, timur timur laut, tenggara, timur tenggara, selatan, barat daya dan barat daya. Untuk batu ultrabasa, arah sebarannya diduga hampir merata dan dominan pada sekitar bagian tengah lokasi penelitian, arah barat barat daya, barat, barat-barat laut, timur laut, timur-timur laut, timur tenggara serta selatan

Kata kunci : Pemodelan, anomali magnetik, dua dimensi, Miomaffo Barat

Abstract

This research on subsurface rock modeling in two dimensions using magnetic anomaly data was carried out in West Miomafo, North Central Timor Regency, which aims to determine the rock layers and their distribution.  In this study, magnetic anomaly data were obtained from the Proton Precession Magnetometer (PPM) GSM-19T type, where the data consisted of a total magnetic field and daily variations.  Qualitative interpretation of the research results shows the presence of low, medium and high anomalies, while the quantitative interpretation suggests the presence of sandstone, clay, limestone and ultramafic rocks as constituents of subsurface rock layers.  Sandstone and clay are thought to be scattered locally around the northwest, southeast, east, south, and southwest directions.  Meanwhile, limestone is thought to have a local-local distribution direction in the direction of around northwest, north, east, northeast, northeast, southeast, east southeast, south, and southwest.  For ultramafic rocks, the distribution direction is assumed to be almost evenly distributed and dominant around the center of the study site, in the southwest, west, west-northwest, northeast, east-northeast, east-southeast and south directions.

Key words: Modeling, magnetic anomaly, two dimensions, West Miomaffo