Multi-Scale Organization of the Doumbouo-FokouéBauxites Ore Deposits (West Cameroon): Implication to the Landscape Lowering

• 作者: Momo Nouazi Mathieu Tematio Paul Yemefack Martin
• 来源期刊: 地质学期刊(英文)
• 学科: 医学
• 关键词: Bauxitic PLATEAUS SAPROLITE FACIES Pisolith FACIES RELIEF lowering West Cameroon
• 年，卷（期）: 2012,（1）
• 页码范围: 14-24
• 页数: 11页
• 分类号: R73

摘要

Landscape distribution, macroscopic, microscopic, mineral and geochemical characterizations were conducted on the Doumbouo-Fokoué bauxite ore deposit in order to estimate bauxites potential and its implication to general lowering of the relief. Fourteen bauxitic plateaus covering a surface area of 5.7 km2 were identified. Bauxitic pedons show deep weathered profiles (10.0 - 12.0 m) with thick bauxitic mantle (4.0 - 8.0 m). Saprolite and pisolith bauxitic facies own high aluminium (47.5% - 49.5% Al2O3), relatively low iron (20.0% - 22.0% Fe2O3) and low silica contents (1.8% - 7.6% SiO2). Gibbsite is the dominant mineral (49% - 68% of minerals detected by X-ray);meanwhile hematite, goethite and kaolinite occur in small amounts. Bauxitization corresponds to intense allitization with abundant accumulation of gibbsite and development of lateritic iron bearing ortho-bauxites. Bauxite ores yielded bauxite reserves of 9.2 million tons. They occur as old and residual bauxitic mantles representing remnants of the Miocene residual lateritic deposits in West Cameroon referring to the African surface of Valeton [1]. Its mean altitude (1532 - 1590 m als) below the African surface reveals general lowering of the relief.