Occurance of Interdunal Soda Depressions in the Mangagrass Land of Yobe State and their Impact on the Economic Geology

Manga Grassland constitutes an important geologic zone and a unique landscape of interdunal soda depressions within the semi ? arid southern Sahel of Yobe state, Nigeria. Two fold methodological approach; field observations and previous investigation findings were used to demonstrate the existence of these phenomena, which are believed to be controlled by complex and amalgamated factors of water balance, xeric climatic condition and nature of geology. Results of analyses of some samples of these phenomena shown they are laden with large deposits of sodium carbonates and Bicarbonates largely in form of trona, which its reserve estimate shown it be over 800 million tons abound the study area.