Regional tectonic and geochemical approach to distinguish bauxite characteristics in Pahang, Malaysia and West Kalimantan, Indonesia

[摘要] Indonesia and Malaysia are neighboring countries that situated in a tropical area and suitable for weathering, particularly favorable for lateritic deposit. One of laterite deposit is bauxite, where bauxite was formed as a chemical weathering product of metaluminous to peraluminous igneous rocks. The study area is located in the Kuantan area, Pahang State, Malaysia and West Kalimantan Province, Indonesia, which has contrasting tectonic origin and serve a different parent rock of bauxite. This study aims to distinguish the geochemical characteristics of bauxite in West Kalimantan against bauxite in Pahang Province. Method used in this study consists of pitting examination, where samples were collected from surface to maximum 10 m intervals and vertically logged. Samples were analyzed petrographically, XRD and XRF in order to observe the mineralogical composition and chemical compound. Result shows that magmatism in Pahang is dominated by basalt with oxide concentration of Al2O3, Fe2O3, SiO2 and TiO2 respectively ranges from 43.96 - 51.01%, 16.59 - 18.97%, 2.17 - 9.01% and 2.83 - 2.91%. In Indonesia, the parent rock of andesite and diorite (Al2O3 = 48.11 - 53.49%; Fe2O3 = 6.15 - 17.25%) shows higher amount of Al2O3 than that in granodiorit (Al2O3 = 30.10 - 48.68%). It can be inferred that andesite and diorite as bauxite's parent rock found in Kalimantan Barat generates abundant gibbsite and higher proportion of Al2O3 with lesser goethite and hematite (Fe2O3) relative to basalt as bauxite's parent rock in Pahang.

[发布机构] Geological Engineering Study Program, Faculty of Earth Technology and Energy, Universitas Trisakti, Jl. Kyai Tapa no.1, Grogol, Jakarta Barat, Indonesia^1;PT Aneka Tambang Tbk, Unit Geomin, Jl. Letjen T.B. Simatupang no.1, Lingkar Selatan, Tanjung Barat, Jakarta Selatan, Indonesia^2

[效力级别] 矿业工程

[关键词] Chemical weathering;Geochemical approaches;Geochemical characteristic;Magmatisms;Mineralogical compositions;Peraluminous;Regional tectonics;Study areas