VOL. 11, NO. 7, APRIL 2016 ISSN 1819-6608 ARPN Journal of Engineering and Applied Sciences ©2006-2016 Asian Research Publishing Network (ARPN). All rights reserved.
RADON AND THORON MAPPING TO DELINEATE THE LOCAL-FAULT
IN THE WAY RATAI GEOTHERMAL FIELD LAMPUNG INDONESIA
Nandi Haerudin1, Karyanto1 and Yudi Kuntoro2
1Department of Geophysical Engineering, Faculty of Engineering, University of Lampung, Indonesia
2Research and Development Center for Oil and Gas “LEMIGAS”, Indonesia
The Survey in the area of geothermal Way Ratai Lampung has been conducted to measure the concentration of Radon and Thoron. The Radon detector RAD 7 used to get field data. The measurement points are 70 stations. These were taken with 200 m – 400 m spacing stations which cover an area of 10 km2. Study area covered four hot spring geothermal manifestations namely Bambu Kuning, Padok, Margodadi and Way Asin. The aim of this study is to determine the local fault based on the profile of Radon concentration. The observation data were taken in 15 minutes for each station measurement to obtain the value of the Radon concentration accurately. After the Radon concentration values are obtained, it made a contour map. The peaks of contour were connected by a line to get the delineation of the local fault. The result showed three lineament anomalies through geothermal manifestations that indicating as the local fault, namely F1, F2, and F3. The first delineation fault (F1) connected Bambu Kuning and Margodadi hot springs in the northwest to southeast direction. The second (F2) connected Padok and Way Asin hot springs in the southwest to northeast directions. The third (F3) passed Margodadi hot spring in the same direction with F2. Based on the Radon to Thoron ratio, F1 and F2 were suggested as the fault that extends to depth. Both are suggested as the conduit of geothermal fluid.