Analisis Efektivitas Konfigurasi Pole-Dipole Pada Geolistrik Dengan Tiga Metode Inversi Berbeda Di Res2dinv Untuk Pemodelan Bawah Permukaan

Ryuliano, Muhammad Luthfi (2025) Analisis Efektivitas Konfigurasi Pole-Dipole Pada Geolistrik Dengan Tiga Metode Inversi Berbeda Di Res2dinv Untuk Pemodelan Bawah Permukaan. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Permasalahan utama di daerah penelitian ini adalah penentuan metode yang tepat untuk pemetaan bawah permukaan secara lateral dan vertikal dengan akurasi data yang tinggi, mengingat kondisi wilayah yang berbukit dan tidak rata. Sehingga penelitian ini bertujuan untuk menganalisis efektivitas konfigurasi pole-dipole pada metode geolistrik Induced Polarization dan Resistivitas (IP-RES) untuk mengatasai masalah pada daerah penelitain dengan membandingkan tiga pendekatan inversi yaitu least square, robust, dan combined. dalam perangkat lunak RES2DINV untuk pemodelan bawah permukaan di daerah mineralisasi sulfida. Metode ini memanfaatkan sensitivitas IP terhadap mineral logam konduktif seperti pirit serta perbedaan resistivitas batuan akibat porositas dan kandungan fluida. Inversi least square menghasilkan model halus dan stabil, sesuai untuk zona homogen, namun cenderung menyamarkan anomali tajam; Robust lebih cocok untuk mendeteksi struktur diskontinu dengan menjaga nilai ekstrem, sementara combined menawarkan keseimbangan keduanya. Pengujian dilakukan pada dua lintasan sepanjang 2200 meter dengan kedalaman hingga 700 meter, dan faktor damping bervariasi dari 0,1 hingga 1 dengan rentang 0.05. Hasil menunjukkan bahwa Combined inversion menghasilkan absolute error terendah pada penampang resistivitas (2,6-2,8%) dengan visualisasi geologi yang utuh, sedangkan least square lebih unggul dalam interpretasi chargeability dengan kontur halus dan error 2,3-4,2%. Robust cocok untuk chargeability ekstrem namun menghasilkan model resistivitas kasar dan error tinggi (hingga 13,3%). Hasil interpretasi menunjukkan bahwa lintasan 1 mengindikasikan keberadaan granit atau quartzite teralterasi dengan kandungan sulfida rendah hingga sedang (pirit/kalkopirit), ditandai oleh resistivitas 600–1500 Ωm dan chargeability 15–50 mV/V, serta zona lempung termineralisasi. Lintasan 2 didominasi batuan beku segar (granit/andesit) dengan resistivitas >1500 Ωm dan chargeability <10 mV/V, namun juga ditemukan zona mineralisasi sulfida (galena/kalkopirit) hingga sulfida masif (chargeability >100 mV/V). Kombinasi resistivitas dan chargeability efektif untuk identifikasi zona prospek mineralisasi. Oleh karena itu, pendekatan optimal adalah kombinasi metode: Combined untuk resistivitas dan least square untuk chargeability, agar diperoleh hasil yang representatif terhadap kondisi bawah permukaan daerah mineralisasi sulfida.
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The main issue in this study area is determining the most appropriate method for accurate subsurface mapping both laterally and vertically, considering the hilly and uneven terrain. Therefore, this research aims to analyze the effectiveness of the pole-dipole configuration in the Induced Polarization and Resistivity (IP-RES) geoelectrical method to address the challenges in this region by comparing three inversion approaches least square, robust, and combined using the RES2DINV software for subsurface modeling in sulfide zones. This method leverages the sensitivity of IP to conductive metallic minerals such as pyrite, as well as variations in rock resistivity due to porosity and fluid content. The least quare inversion produces smooth and stable models, making it suitable for homogeneous zones, but it tends to smooth out sharp anomalies. The robust method is more effective in detecting discontinuous structures by preserving extreme values, while the combined inversion offers a balance between the two. The tests were conducted on two survey lines, each 2200 meters long and reaching depths of up to 700 meters, with damping factors ranging from 0.1 to 1, incremented by 0.05. Results show that the combined inversion yields the lowest absolute error in resistivity sections (2.6-2.8%) with coherent geological visualization, while the least square approach performs better for chargeability interpretation, producing smoother contours with an error range of 2.3-4.2%. The robust method is suitable for highlighting extreme chargeability values but results in rough resistivity models with higher errors (up to 13.3%). Interpretation results indicate that Line 1 reflects altered granite or quartzite with low to moderate sulfide content (pyrite/chalcopyrite), characterized by resistivity values of 600–1500 Ωm and chargeability of 15–50 mV/V, along with clay-rich mineralized zones. Line 2 is dominated by fresh igneous rocks (granite/andesite) with high resistivity (>1500 Ωm) and low chargeability (<10 mV/V), but also reveals zones of sulfide mineralization (galena/chalcopyrite) and massive sulfides (chargeability >100 mV/V). The combination of resistivity and chargeability proves effective for mapping and identifying prospective mineralization zones. Therefore, the optimal approach is to combine methods: using combined inversion for resistivity and least square for chargeability, in order to obtain results that best represent the subsurface conditions of sulfide areas.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Pole-Dipole Configuration, Induced polarization, Pole-Dipole Configuration, 2D Inversion, Resistivity, Konfigurasi Pole-Dipole, Induced polarization, Inversi 2D, Resistivitas.
Subjects:	G Geography. Anthropology. Recreation > GA Mathematical geography. Cartography > GA105.3 Cartography. Q Science > QE Geology > QE1.F557 Magnetic anomalies--Measurement. T Technology > T Technology (General) > T57.5 Data Processing
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Geophysics Engineering > 33201-(S1) Undergraduate Thesis
Depositing User:	Muhammad Luthfi Ryuliano
Date Deposited:	01 Aug 2025 02:43
Last Modified:	01 Aug 2025 02:43
URI:	http://repository.its.ac.id/id/eprint/123934

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