Mapping bauxite-associated alterations in the Boke region (NW part of Republic of Guinea), using the airborne gamma-ray spectrometry data

Abstract

Mapping of highly altered zones favorable to mineralization is crucial to finding useful mineral deposits. However, several methods have been used to locate areas subject to weathering processes, including analysis of airborne gamma-ray spectrometry data, which have demonstrated accurate and reliable results. In order to target other promising areas, and ensure the sustainability of bauxite mining, gamma-ray spectrometry was carried out and applied for the first time in the Boke region, located in the north–west of the Republic of Guinea which encompassing the world's famous bauxite district. The results obtained from the K/eU, K/eTh ratios, the F parameter and the potassium map were processed by the fuzzy logic model using ArcGIS software, the model can be used to merge the resulting informative maps into a single mineral prospectivity map, serving as a guide for mineral exploration. Three zones of high mineral prospectivity have been identified, essentially the Ordovician formations at Pita, the Silurian at Telimele and the Devonian at Faro. According to these preliminary prospecting results, the delineated areas contain localities that are probably potential, giving the green light for more advanced prospecting.

Keywords

• Aeroradiometric data
• Mineral exploration
• Alterations
• Fuzzy Logic modelling
• Bauxite deposite
• Mineral prospectivity mapping