Petrology of Ultramafic Rocks at Sebuku Island, PT. Sebuku Iron Lateritic Ore, South Kalimantan - Indonesia Ikhwan Rasyidin Hadi Abbas (a*), Adi Maulana (a)
a) Geological Engineering Department, Hasanuddin University, Makassar, South Sulawesi, 90245, Indonesia
*ikhwan.abbas[at]gmail.com
Abstract
Sebuku Island is located in South Kalimantan, Indonesia. It has consisted of Meratus complex^s rock of Mesozoic to Cenozoic aged in the eastern of the island. The research area is in the concession area of PT. Sebuku Iron Lateritic Ore, which is indicated to consist of ultramafic rock. Using petrography method to observe the rock in the thin section and describes the rock^s type also the level of serpentinization. Ultramafic rocks in this area consist of peridotite type with varying levels of serpentinization. Not only peridotite but it consists also of serpentinite and gabbro. Type of serpentine minerals like lizardite, chrysotile, and antigorite with chlorite, magnetite, and talc as the alteration minerals. The textures of serpentinization are mesh, bastite, blades/flaky, hourglass, vein and veinlet.
