Identification of Mineralization Type and Specific Radioactive Minerals in Mamuju, West Sulawesi

Mamuju is the capital city of West Sulawesi province that has high value of natural radiation dose rate (radioactivity). The specific minerals that expose the radioactivity not determined clearly. The purpose of this study was to determine of specific radioactive minerals and its type of mineralization in Mamuju area. The study was conducted by geological mapping, radiometric in order to identification the form and distribution of radioactive mineralization. Geochemical analysis was done by field sampling, mineralogy and SEM-EDS analysis to determine the specific radioactive mineral. The distribution of the value of radiation dose rates and occurrences of mineralizations are found only on the Tapalang, Ampalas, Adang and Malunda alkaline volcanic rocks complex. Radioactive minerals formed as a primary mineral are davidite ((U,Ce,Fe)2(Ti,Fe,V,Cr)5O12) and thorianite (ThO2). Beside the primary minerals also found the secondary minerals such as gummite (UO3.nH2O) and autonite (CaO.2UO3.P2O5.8H2O) as well as in association with sulphide minerals. Radioactive mineralization type are volcanic related uranium deposit structural bound and supergene enrichment type which are controlled by lithology, geological structure and hydrothermal process. Existance of davidite, thorianite, gummite and autonite in alkaline volcanic rock will produce high natural radioactivity. Therefore those locations can be developed to be exploration target