MINERALOGY AND ENRICHMENT OF ION-ADSORPTION TYPE REE ON WEATHERED GRANITOID PROFILES IN WEST SULAWESI: IMPLICATIONS FOR EXPLORATION

• Main Author: Febbi Alvionita, A.
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/73853
• Institution: Institut Teknologi Bandung

The rare earth elements (REE) are the lanthanide+Y+Sc group of elements which are currently needed in the industrial world and are raw materials for making advanced and modern technology. As the need for REE increases, REE exploration activities also increase, therefore this research was conducted as a preliminary study which aims to determine the characteristics of the REE adsorption type in West Sulawesi using optical mineral petrography, X-ray diffraction (XRD), X-ray fluorescence (XRF), and inductively coupled plasma mass spectrometry (ICP-MS). Optical mineral observations show that the source rock at Polewali is quartz monzonite, while at Mamasa it is granodiorite. REEbearing minerals seen on optical mineral petrography are zircon, apatite, alanite and monazite. Clay minerals that have been successfully detected as minerals that bind REE in the weathered zone are kaolinite, halloysite, montmorillonite and nontronite. REE enrichment in the A horizon on both profiles shows that the percentage of clay minerals also affects the amount of TREE, as evidenced by the percentage of kaolinite content of around 13.3% and 5.3% halloysite, more than in the other horizons. The positive Ce anomaly in the weathered samples indicates that both weathered profiles are leaching zones except for the A horizon in Mamasa. The negative Eu anomaly also indicates that plagioclase was released during the differentiation of magma process when rocks are formed. Factors that influence the distribution and accumulation of REE are the type of source rock and the degree of weathering.