The mining area lies west African Craton in northwest Africa , located west of the Republic of Guinea . mainly composed of Precambrian basement overlain by Paleozoic-Cenozoic stratigraphy , Precam-brian basement consists of metamorphic rock series of archaean group , distributed mixed granite , and greenstone belt , w hich is the main Ore-forming parent rock of large metal deposits . South ore block of the Exploration Area is close to Atlantic ocean . It is about southwest of 40 km from the Atlantic coast , be-longs to "Lower Guinea"coastal plain area;North ore block is located in the junction of Middle Guinea and Lower Guinea , belong to low mountain area , eastern border with Fouta Djallon plateau of Middle Guinea . This is weathering residual type bauxite deposits , it is easy for mining technical condition , the main natu-ral ore type is Gibbsite , industrial type is high iron and low sulfur type , is the world most easily ore type under the condition of the bayer process