Volcanic deposit thickness in the area around Manglayang Mountain by one-dimensional data interpretation of magnetotelluric

Abstract

The Manglayang mountain is one of volcanoes located in Bandung Basin area, it is limiting the Lembang active faults in the eastern part. Relationship between those can be interpreted by the information of volcanic deposit thickness and it has conducted by Magnetotelluric method (MT). This method utilizing the sources of natural electromagnetic wave that induce subsurface rocks and produce secondary fields which can be measured orthogonally on the surface. The results are presented in the form of resistivity rock variation resulting by one dimensional (1D) inversion. Interpretation of volcanic deposit thickness in the eastern of Manglayang Mountain indicated reaches 443 m (55-115 Ωm). It is unconformable on soft sediment (3-13 Ωm) with thickness 1,671 m. Those products covered the basement rock (11-42 Ωm). The subsurface geological conditions suggest that the dominated by low resistivity values (<1000 Ωm) suspected correlated with the soft rock as clay, sand, high porosity rocks, and the weathered rock. It is very different from western part of Manglayang mountain which consist of igneous rock dominantly, so that the relationship with Lembang active faults can interpreted separated by geological structure.