Petrology of ultramafíc Rocks from PT. Sebuku Iron Lateritic Ore (SILO) concession area and Its Effect on Ni and Fe in Sebuku Island, South Kalimantan, Indonesia

Abstract

Widely distribution of serpentinization rock especially ultramafic rocks in Sebuku Island, South Kalimantan, primarily in the concession area of PT. Sebuku Iron Lateritic Ore (SILO). Some representative samples were taken from the site and analyses the level of serpentinization to determine the characteristic of the rocks. The ultramafic rocks in the study area consist of peridotite with a low to high degree of serpentinization to serpentinite. The pseudomorph textures are shown like mesh, bastite, blades/flaky, hourglass, vein, and veinlet. Serpentine occurs as lizardite, chrysotile, and antigorite. Geochemical analysis like XRF (X-ray fluorescence) was used to find out the composition element. By this analysis, the wt.% of the element will be shown and determine the level of Nickel (Ni), and Iron (Fe), and the level of serpentinization also. The Serpentinization levels are affecting Ni and Fe. The higher the serpentinization level, the higher Fe (wt.%), whereas the higher level of serpentinization, the lower Ni (wt.%).