PHASE TENSOR AND MODELING OF MAGNETOTELLURIC DATA TO DETECT FAULT STRUCTURES IN ETHERIDGE AREA

Abstrak

This study aims to identify subsurface fault structures in the Etheridge region, Queensland, Australia, using the magnetotelluric (MT) method. The data used consists of 21 secondary MT points from Geoscience Australia. Phase tensor analysis shows the dominance of a 2D structure with a geophysical direction of N175°E, which is then used as the basis for 2D inversion modeling using the Non-Linear Conjugate Gradient (NLCG) algorithm to a depth of ±2.2 km. The modeling results show a low-to-medium resistivity zone (<500 Ωm) interpreted as a fault zone and fluid-saturated rock, as well as high resistivity (>1500 Ωm) representing igneous-metamorphic rock. The main structures identified are the Delaney Fault and the Palmerville Fault. The novelty of this study lies in the mapping of regional fault continuity based on phase tensor integration and 2D inversion, which provides a better understanding of tectonic control and potential fluid flow pathways in the Etheridge area.