Geoelectric Prospection of Copper Occurrence in Folding Layers in the Sul-Riograndense Shield (Brazil)

Abstract

Sulfide prospecting with the geophysical methods, such as electrical resistivity and induced polarization, are promising due to the contrast of electrical resistivity and chargeability, where deposits with disseminated sulfides or filoneans are characterized by low resistivity and high polarizability. This work carried out a study of geophysical prospecting by means of tomographic acquisition in mineral copper occurrence, in the region of Caçapava do Sul. Three acquisition lines were performed by means of electrical tomography technique using a Dipole-dipole arrangement, with a length of 400 m and a spacing of 5 m between the electrodes, arranged in perpendicular layout to the structure of the area, represented by a large synclinal where research galleries with carbonates and copper sulfides were recognized in the ridge. The 2D inversion models and 3D multilevel maps indicate central and lateral regions with high resistivity and chargeability with indication of probable presence of copper sulfide, possibly housed in quartz veins. Peripheral zones with moderate resistivity and chargeability infer possible areas with presence of argilization, zones with high chargeability and low resistivity are likely to be zones of sulfation and possible silicification zones with high resistivity and low chargeability, observed in the vicinity of the probable mineralized zones.Keywords: Chargeability, Mineral Research, Resistivity, Sulfide, 3D Multilevel modeling.RESUMO A prospecção de sulfetos por meio de métodos geofísicos de eletrorresistividade e polarização induzida são altamente efetivos devido ao contraste de resistividade elétrica e cargabilidade, uma vez que os depósitos com sulfetos disseminados ou filoneanos são cvaracterizados por baixa resistividade e alta polarizabilidade. Esse trabalho realizou aquisição de tomografia elétricas em ocorrência mineral de cobre, na região de Caçapava do Sul (RS). Foram realizadas 3 linhas de tomografia elétrica em arranjo dipolo-dipolo, com 400 m de comprimento e 5 m de espaçamento entre eletrodos, dispostas de forma perpendicular à crista de um anticlinal, onde no passado foram reconhenhecidos carbonatos e sulfetos de cobre, em galerias de exploração mineral. Os modelos de inversão 2D e mapas de multiníveis 3D indicam regiões centrais e laterais com alta resistividade e alta cargabilidade com provável zona de sulfetos alojados em veios de quartzo. Zonas periféricas com moderada resistividade e cargabilidade sugerem a presença de argilização; zonas com alta cargabilidade e baixa resistividade são prováveis zonas de sulfetação e altos valores de resistividade e baixos de cargabilidade indicam zonas de silicificação.Palavras-chave: Cargabilidade, Pesquisa Mineral, Resistividade Elétrica, Sulfeto, Modelamento Multinível 3D.

Identifikasi Persebaran Batuan Andesit Sebagai Bahan Utama Agregat Menggunakan Metode Geolistrik Profiling Konfigurasi Wenner-Alpha

“…Agar memastikan potensi tersebut sesuai harapan, perlu adanya pendekatan metode tidak langsung untuk mengecek keberadaan batu andesit, salah satunya menggunakan metode geolistrik profiling. Metode ini merupakan teknik resistivitas 2D yang umum digunakan dalam menganalisis lapisan air tanah (Antosia et al, 2022;Antosia and Ramdan, 2023;Gemilang et al, 2018;Minarto et al, 2021;Padlilah et al, 2021), mengindentifikasi bidang gelincir untuk zona rawan longsor (Simanjuntak and Cahyo, 2022;Souisa et al, 2015;Taufiqurrohman et al, 2017), mengeksplorasi mineral tambang (Arifin et al, 2019;Azis et al, 2019;Bahri et al, 2021;Fernandes et al, 2018;Yuniarto, 2020), dan tentunya dapat juga digunakan untuk investigasi sebaran batu andesit (Antosia et al, 2021;Prastowo, 2018;Ratminah et al, 2021;Simamora et al, 2021;Wahyono et al, 2020).…”

Beneath the Surface: Identifying Subsurface Caves in "Gua Pandan" Using Integrated Electrical Profiling Method

“…The second one is the induced polarization method, which is generally applied to mineral exploration, for instance, gold [18][19][20][21][22][23][24][25], copper [26,27], and galena [28,29]. However, only a few researchers utilized it for underground cave detection, all deployed dipole-dipole arrays [12][13][14].…”