The Bodélé Depression (pronounced [bɔ.de.le]), located at the southern edge of the Sahara Desert in north central Africa, is the lowest point in Chad.

The dry bowl that forms the depression is marked by a series of ephemeral lakes, many of which were last filled during wetter periods of the Holocene.

As the waters receded, the silts and sediments resting on the lakebed, which included fossilized diatoms, were left to dry in the scorching sun, forming a layer of fine dust.

The effect of the Tibesti massif is clearly evident in creating a split in the low-level easterly flow north and south of these mountains.

[9][10][11] The research also shows that, contrary to what was previously thought, most of the Saharan dust that reaches the east coast of the United States originates from a single source—the Bodélé depression.

[3] This work coincided with a major dust emission event during which the Bodélé Low Level Jet sustained surface wind speeds of around 16 m/s.

Instead of a simple coincidence of nature, the world's largest dust source results from a system of processes operating over paleo timescales.