Bodélé Depression

The Bodélé depression is a depression in the center of Chad on the southern edge of the Sahara. In the north and north-east it is bounded by the Tibesti mountains or the Windkorrasionsgebiet of Borkou, on the west by the Erg du Bilma and to the east and south by the desert of Erg you Djourab. This area covers an area of ​​approximately 35,000 km ² from 16 ° 05 ' to 17 ° 38' north latitude and spreads 15 ° 50 ' to 18 ° 50' east longitude. It is located about 600 km north of present-day Lake Chad and labeled with 155 180 m, the deepest valley in the Chad Basin.

On satellite images, the surface seems to be the Bodélé depression to be made of white, yellow stripes and spots with resting, migrating south Barchanen. In the white Oberflächenaterial is strongly eroded, extensive Diatomitsedimeten older lake deposits that lie on older sand dunes and covers a large area of yellow -colored sands of the younger eolian Sedimentationphase. One finds in the Bodélé depression also fine and loose clay material in the form of younger alluvial before, these have been deposited in the valley due to the denudativer processes in the Tibesti Mountains.

In the Bodélé depression occur at an average 100 days a year, dust storms, which probably contribute to the minerals in the Amazon. An illustrative example of these dust storms was photographed on 18 February 2004 by NASA. The dust consists to a large part of deposits of diatoms, as the depression is the former property of a large prehistoric lake and the valley until 4000 years ago partially contained water.