The Chad basin has been forming on a section of the Precambrian African Shield for thousands of years. Evidence of crystalline rock has been found under the more recent deposits. Researchers believe that the ancient sea, Mega-Chad, had the most significant influence on the formation of the Chad basin because the basins of the sea and the lake overlap in some areas. The sea itself was over 600 ft (180 m) deep in most regions and covered over 154,400 square miles (441,584 square km) of central African land before draining into the Atlantic Ocean via the Benue River. The floor of the Chad basin intersects with the ancient Mega-Chad basin in the northeastern portion of Lake Chad at the lowest point of the lake called the Djourab Depression.
© Copyright 1998, ThinkQuest team 16645
All rights reserved.