Airborne Magnetic and Radiometric Geophysical Mapping in South and Central Range Mountains, Papua Indonesia.

Abstract

The Center for Geological Survey (CGS) of Geological Agency, Indonesia, known as Pusat Survei Geologi, commissioned an airborne magnetic and radiometric survey covering the Indonesian Papuan Central Highlands Region and the southern side of the highlands during 2010 and 2011. The survey was funded by the State Revenue and Expenditure of the Ministry of Energy and Mineral Resources of The Republic of Indonesia and covered an area of 156,964 square kilometres. Geological mapping in this area is recognised as being difficult predominately due to the extreme terrain and weather. The objective of the survey was to map the surface geology as well as sub-surface geology, identify and map the structure of the region, to model new geophysical data along with previously collected ground gravity data, and integrate all the results with the previously known geology. The expected outcome would be a better understanding of the geology and structure in the region and an increase in mineral and oil and gas exploration for Indonesia. The survey consisted of a helicopter based magnetic and radiometric survey in the Central Highlands Region at 500 m spacing totalling 20,045 km and a fixed-wing aircraft based magnetic and radiometric survey over the south side of the highlands at 1,000 m spacing totalling 155,530 km. The results highlighted and extended the geological, structural, and tectonic evolution knowledge of the region and identified areas for further mineral and oil and gas exploration. The modelling of the magnetic and gravity data supported the interpretation and added further information to the depth analysis of the data.