DISCOVERY OF ASBUTON

The early exploration of the asbuton deposits was carried out by mining engineers and geologists of the Nederlands Indies Geological Survey in the early 1920's to 1930's, with publication of preliminary results in the mid 1920's to late 1930's. The earliest reports were composed by Van Haeften (1924) and Zwierzycki (1925). Bothe (1928) reported on the some deposits areas, which because of their location were considered a favorite for development at the time.

Hetzel (1936) reviewed the work to date and and outlined 19 "asphalt fields" or deposits and presented geologic and resource evaluation results for each deposit.

Van Bemmelen (1949) in his treatise on the geology of the Indonesian archipelago reviews both the geology of Buton Island and the resources and origin of asbuton deposits.

In 1960-61 Pacific Consultants (1961) of Tokyo carried out a detailed geological and geophysical survey of an area named Lawele in south Buton Island. This detailed evaluation showed that the Lawele deposit occurs over a large area and "huge amounts of rock asphalt is certainly anticipated" (Pacific Consultants, 1961, p.20).

In another area a bit lower named Kabungka where mining of the asbuton deposits has been intermittently carried out since 1926, resource evaluation and geological studies have been more numerous. The Cameron McNamara (1980) study defined resources of several of the deposits there. In addition, the Kasoep et al (1975) drilling and the Hardjono (1966) geophysical study have served to further define the Kabungka asbuton resources. PT. Sarana Karya has a large amount of unpublished exploration and mine planning data in its Kabungka offices. This data is the most definitive mining reserve estimate available for Kabungka area.

Sarah, Saroso and Suharto (1986) in their proposal for the exploration of the asphalt areas of Buton Island give a history of and a reference list for papers and reports on the asbuton deposits. This proposal was a valuable resource for the author. Hamilton (1968) discusses Buton Island in terms of  microplate movements in the evolution of the Indonesian archipelago. Wiryosujono and Hainim (1975) discuss the geologic history history of Buton Island in light of modern theories on plate tectonics. Sikumbang and Sanyoto (1981, 1984) also discuss the geology of Buton Island and present a detailed geological map (scale of 1:250,000) as well as a comprehensive reference list to the geological literature on Buton Island.

Since 1988, Conoco Indonesia has been carrying out detailed, basic geologic mapping on Buton Island in their exploration for conventional oil and/or natural gas deposits. In this mapping program Conoco geologists have located a number of asbuton occurrences on both north an south Buton Island which were not previously known. In addition, seeps of high gravity oil were discovered and sampled. Planned seismic work to delinate the structure of the sedimentary succession on Buton Island will contribute immeasurably to the knowledge of the geologic history of Buton Island and the location, size and origin of the asbuton deposits. Any further detailed exploration of the Buton Island asbuton deposits should certainly avail themselves of the up-to-date, detailed geologic information being gathered by Conoco Indonesia.