Recognition of boulder in granite deposit using integrated borehole and 2D electrical resistivity imaging for effective mine planning and development

Abstract

Evaluations of a mineral resource are necessary for mineral rights, owners and investors alike. However, for resource evaluation the detail documentation of subsurface geological spatial distribution such as lateral and vertical extent of bedrock and topsoil, hydrogeological investigation and boulder characterisation is mandatory. Boulder is hard and crystalline compact rock block, which substantial presence in a deposit highly influence the drilling equipment selection. A traditional exploration technique particularly for granite resource evaluation is drilling. But even finite number of drilling sample fails in the accurate delineation of boulders because drilling is limited to small point and rock mass is heterogenous and thus immense portion of the deposit via drilling method remain discern. 2D electrical resistivity imaging (2D ERT) technique of the study area over an area of 3.5 km 2 was accomplished by six resistivity lines using a Schlumberger protocol with inner and outer electrode spacing of 5 m and 10 m respectively. Inverted resistivity images successfully identify the existence of boulders in the area of investigation in the topsoil region; characterized by high resistivity values more than 2400 Ω.m. Whereas, only one core log (BH3) out of three reported presence of boulders. Thus, the research study presented in this paper enables us to conclude that the combined application of borehole and ERT allows us to derive that 2D ERT enhances the resource evaluation efficiency and reduces the cost considerably for underlying subsurface geological characterization.

Determining the origin of volcanic rocks in the mélange complex of Karangsambung based on the electrical resistivity imaging

“…For this purpose, we applied the electrical resistivity imaging. The method has been efficiently used in (Junaid et al, 2019) for the subsurface investigation to find granite boulders. Previous researches have used it for volcanic body investigations (Barde-cabusson et al, 2013;Ingham, 2005;Troiano, Isaia, Di Giuseppe, Tramparulo, & Vitale, 2019).…”

Hydrogeophysical Characterization of Fractured Aquifers for Groundwater Exploration in the Federal District of Brazil

“…The ERT technique has been widely used to investigate many sites around the world for various purposes, including bedrock detection, geological mapping, and groundwater exploration [6][7][8][9][10]. Recent case studies of hard rock aquifers in Brazil have highlighted the significance of regional structures, hydrogeology, and petrophysical properties of the site in groundwater development [2,[11][12][13][14].…”