Ketebalan Lapisan Sedimen Molasa Sulawesi Daerah Labokeo, Konawe Selatan Berdasarkan Penampang Electrical Resistivity Tomography

Al Rubaiyn; La Ode Ngkoimani

doi:10.56099/ophi.v5i1.p28-34

Authors

Al Rubaiyn Jurusan Teknik Geofisika, Universitas Halu Oleo https://orcid.org/0000-0003-0636-9821
La Ode Ngkoimani Jurusan Teknik Geologi, Universitas Halu Oleo https://orcid.org/0000-0001-9076-9355

DOI:

https://doi.org/10.56099/ophi.v5i1.p28-34

Keywords:

Electrical Resistivity Tomography, Molasa Sulawesi, Langkowala

Abstract

Desa Labokeo merupakan area yang keseluruhan ditutupi oleh sedimen Molasa Sulawesi. Adanya aktifitas penambangan nikel yang mengindikasikan bahwa terdapat endapan nikel laterit di bawah Molasa Sulawesi di Desa Laboke. Penelitian ini bertujuan untuk mengestimasi ketebalan lapisan sedimen Molasa Sulawesi berdasarkan citra bawah permukaan Electrical Resistivity Tomography (ERT) dekat lokasi penambangan nikel di Desa Labokeo. Metode ERT adalah metode pengukuran resistivitas di permukaan tanah dengan menggunakan banyak elektroda, agar diperoleh variasi distribusi resistivitas bawah permukaan secara lateral dan vertikal, sehingga didapatkan citra bawah permukaan. Akuisisi data ERT menggunakan konfigurasi dipole-dipole. Inversi data ERT menggunakan perangkat lunak Res2Dinv. Berdasarkan penampang inversi ERT diperoleh bahwa nilai resistivitas perlapisan sedimen di lokasi yaitu resistivitas batupasir > 250 Ohm.m dengan ketebalan 5-29 meter, dan resistivitas batulempung-lanau 10,4 – 100 Ohm.m dengan ketebalan hingga 60-90 meter. Batuan ini merupakan batuan sedimen Formasi Langkowala dengan ketebalan hingga 120 meter yang terdiri atas lapisan batupasir yang menindih lapisan batulempung-lanau

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