The signatures study of sinistral-type fault at Krueng Raya, Aceh using 2-D resistivity

Earthquakes that occurred along the Sumatran fault had ruptured to about 20 segments starting with small slip rate at the southernmost and increasing rate to the north end of Sumatra Island. In the Aceh Province; located at the northernmost, the fault system is split into two sub- parallel fault lines (segment) which are Aceh fault and Seulimeum fault. Lithologically, the Aceh Province consists of sedimentary and metamorphic rocks from Late Paleozoic to Quaternary age. The Seulimeum Fault cuts the Lam Teubavolcanics and strongly interfere the Tertiary sediments to the southeast, where it has an element of downthrown to the northeast. The geophysical survey was done aimed to study the features of fault. Using pole-dipole array, the 2D-resistivity covering Krueng Raya districts which located at the Aceh province by several lines with length from 800 m up to 1200 m with minimum 20 m electrode spacing. The data processed using Res2Dinv and result presented using Surfer8 software shows two major areas of overburden and bedrock. The layer of overburden consists of alluvium with resistivity value of 10-800 Ωm located at a depth 140 Ωm. The fault identified by the contrast of low and high resistivity value.