Implications of Non-Carbonate Dolomite Minerals in the Formation of Red Soils in a Paleokarstic Context in the Taoudeni Basin in Burkina Faso  

作　　者：Fidèle Kaboré Gounwendmanaghré Hubert Zongo Bright Fafali Dogbey Korodjouma Ouattara Younoussa Millogo Limata Kaboré Edmond Hien Prosper N. Zombré Fidèle Kaboré;Gounwendmanaghré Hubert Zongo;Bright Fafali Dogbey;Korodjouma Ouattara;Younoussa Millogo;Limata Kaboré;Edmond Hien;Prosper N. Zombré(Laboratoire Sols, Matériaux et Environnement (LSME), Université Joseph KI-ZERBO, Ouagadougou, Burkina Faso;Laboratoire de Géosciences et Environnement Minier, Université de Fada, Ouagadougou, Burkina Faso;Department of Soil Resources Management, CSIR-College of Science and Technology, Accra, Ghana;Institut de l’Environnement et de Recherches Agricoles (INERA), Ouagadougou, Burkina Faso;Unité de Formation et de Recherche en Sciences et Techniques (UFR/ST), Université Nazi BONI, Bobo-Dioulasso, Burkina Faso;Bureau des Mines et de la Géologie du Burkina Faso (BUMIGEB), Ouagadougou, Burkina Faso;Institut de Recherche pour le Développement (IRD), Montpellier, France)

机构地区：[1]Laboratoire Sols, Matériaux et Environnement (LSME), Université Joseph KI-ZERBO, Ouagadougou, Burkina Faso [2]Laboratoire de Géosciences et Environnement Minier, Université de Fada, Ouagadougou, Burkina Faso [3]Department of Soil Resources Management, CSIR-College of Science and Technology, Accra, Ghana [4]Institut de l’Environnement et de Recherches Agricoles (INERA), Ouagadougou, Burkina Faso [5]Unité de Formation et de Recherche en Sciences et Techniques (UFR/ST), Université Nazi BONI, Bobo-Dioulasso, Burkina Faso [6]Bureau des Mines et de la Géologie du Burkina Faso (BUMIGEB), Ouagadougou, Burkina Faso [7]Institut de Recherche pour le Développement (IRD), Montpellier, France

出　　处：《Open Journal of Soil Science》2021年第2期59-71,共13页土壤科学期刊（英文）

摘　　要：Uncertainties remain as to the ability of certain carbonate rocks to form the red soils covering them. These doubts, which have been the subject of debate for several decades, become real when carbonate rocks are pure and low in insoluble residues. In the carbonate rocks of the Taoudeni basin in Burkina Faso, brown-red to red soils develop, at the top of hillsides and in karstic cavities. No study in the region has yet shown the existence in these carbonate rocks of sufficient insolubles to form soils after decalcification. The objective of this study was therefore to identify and quantify the minerals of carbonate rocks in order to identify the origin of red soils. Petrographic, chemical (XRF) and mineralogical (XRD) investigations on dominant carbonate rocks features in the study area show that the rocks studied are mainly magnesian dolomites (Dolomite > 50% of carbonate minerals and Ca/Mg ratio < 1.5). Non-carbonate residues from detrital and hydrothermal origin, negligible in certain pure dolomites (<2%), are on the other hand significant (>12%) in other dolomitic features. These insoluble silicates formed of quartz, potassium feldspar (orthoclase), clays (talc, phlogopite and kaolinite) and iron oxides constitute the main original material of reddened soils in karstic cavities.Uncertainties remain as to the ability of certain carbonate rocks to form the red soils covering them. These doubts, which have been the subject of debate for several decades, become real when carbonate rocks are pure and low in insoluble residues. In the carbonate rocks of the Taoudeni basin in Burkina Faso, brown-red to red soils develop, at the top of hillsides and in karstic cavities. No study in the region has yet shown the existence in these carbonate rocks of sufficient insolubles to form soils after decalcification. The objective of this study was therefore to identify and quantify the minerals of carbonate rocks in order to identify the origin of red soils. Petrographic, chemical (XRF) and mineralogical (XRD) investigations on dominant carbonate rocks features in the study area show that the rocks studied are mainly magnesian dolomites (Dolomite > 50% of carbonate minerals and Ca/Mg ratio < 1.5). Non-carbonate residues from detrital and hydrothermal origin, negligible in certain pure dolomites (<2%), are on the other hand significant (>12%) in other dolomitic features. These insoluble silicates formed of quartz, potassium feldspar (orthoclase), clays (talc, phlogopite and kaolinite) and iron oxides constitute the main original material of reddened soils in karstic cavities.

关 键 词：DOLOSTONE MINERALOGY Parent Material ALTERATION Rubification 

分 类 号：P59[天文地球—地球化学]