The relationship of asphalt-bearing rocks and the asphalt quality at Sandangpangan Area, Buton Island, Southeast Sulawesi

Buton asphalt is one of the largest natural asphalt deposits in the world. The Asphalt-bearing rocks in Buton Island are calcarenite limestone, bioclastic limestone, and crystalline limestone. This research aims to determine the relationship between asphalt-bearing rocks and asphalt quality. This research uses several methods the soxhlet extraction method to determine bitumen and water content, XRF analysis to determine the chemical content of asphalt, and petrographic observations to determine rock composition and rock porosity. The result shows that, in general, the quality of the asphalt-bearing rocks was influenced by their porosity. With the increase of the porosity of the asphalt-bearing rocks, it will be easier for asphalt liquid to penetrate the rocks. The greater porosity of the rocks will produce the higher quality of the asphalt. The asphalt-bearing rock in the research area with the best bitumen quality is calcarenite limestone, which has the highest porosity level.