Terapan ERT dan SRT pada area Tambang Batubara Terbuka PT.MHU Kaltim

Abstract

Loa Gagak sub-block operated PT MHU is known to have discontinuous coal seam which is interpreted to be the results of wash-out. Moreover, mapping the hard and soft material area seems to be very challenging. Thus, an ERT survey has been conducted using Wenner and Dipole-Dipole configuration with 9 lines each, 235 meters length, and up to 40 meters depth of penetration. The main objective of this study is to delineate the lithology including the coal seam based on the resistivity value on every line of the measurements. The results of ERT survey are displayed in resistivity section as a result of inversion on each line with two configurations. The result of Dipole-Dipole configuration is able to image the North-East trend of coal continuity while Wenner configuration could image the upright stratigraphy trend. Though these two configurations confirms coal seam with NE-SW trend, the results of resistivity imaging need to be optimized using other configuratiosn in order to able to increase the accuracy by correlating them with other geological data. Furthermore, the ERT method has not been able to determine the boundaries of swamp deposits clearly. Another method is needed to identify swamp material so that it can map the thickness and the depth of both soft and the hard material. The SRT method seems to able to image the hardness of the rock based on P-wave velocity based on 3 trial lines. Keywords: coal, ERT, Wenner, Dipole-Dipole, SRT