Identifikasi Struktur Bawah Permukaan Tuff ring Dengan Menggunakan Metode Geolistrik Konfigurasi Dipol-Dipol

Abstract

Tuff ring Geoelectric Resistivity Dipole-dipole The research has been done to identify the subsurface structure of the tuff ring in plantation area Mahawu using geoelectric method of dipole-dipole configuration.It has been divided into two lines measuring with the length of 480 m for each lines, one space 10 m between the electrodes and the line 2 has 240 m length with spaces 5 m between electrodes. The data was obtained and processed using software RES2DINV to get an image of the structure below the tuff ring into two dimensions. The results of data processing shown an image of resistivitas beneath the surface on the line 1. In general, it can be seen that the resistivitas beneath the surface line 1 is dominated by resistivitas more than 300 Ωm (purple colour image). Especially in meter 250-260 and meter 280-290, there are two zones with resistivitas value that is relatively small at less than 50 m. While on the line two, the resistivitas value is less than 60 Ωm (blue and green coloured zone ) that form patterns extend from the maximum depth to the surface, visible form a funnel/the cust from a depth of about 40 m (under electrodes to 18 or in meters to 90) To the surface (under electrodes 25 – 33 or in meters 125 -165) is directed to the northwest-southeast with the angle of inclination of about 40°42°and the resistivitas pattern elongated funnelshaped by contrast it also limited by the high resistivitas (> 300 Ωm) which is a structure with high density and less conductive. Which is interpreted as a former eruption channel preatomagmatic.