100th century BCE – 40th century BCE
Chad Basin
The highstand of palaeolake Chad was a major late-glacial and Holocene hydrological episode in the Chad Basin. After a prolonged dry interval, the lake began expanding shortly before 12,000 BP and reached a maximum level with intermittent overflows around 10,000 BP. Its water surface covered at least 400,000 square kilometres. Several recessions followed, around 8,500, 7,500, and 6,500 BP, and the highstand ended about 4,000 BP.
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The Story
The Chad Basin experienced a long interval of desiccation and aeolian activity from somewhat before 21,000 BP until shortly before 12,000 BP. During this phase, dune fields spread across the savanna in a broad belt from the Atlantic coast toward the Nile Valley. The lake then began to expand again as hydrological conditions improved.
Expansion was briefly interrupted a little before 10,300 BP, but subsequently continued. Around 10,000 BP, the lake reached a maximum level and experienced at least intermittent overflows. The water surface covered approximately 400,000 square kilometres, making this one of the most extensive documented late-glacial and Holocene lake expansions in the African interior.
The highstand was not continuous. Recessions occurred around 8,500, 7,500, and 6,500 BP, before the expanded lake phase terminated about 4,000 BP. The sequence records strong hydrological variability in the southern Sahara and Chad Basin and is linked in the passage to changing rainfall across the wider monsoonal belt.
100th century BCE – 40th century BCE
Chad Basin
The highstand of palaeolake Chad was a major late-glacial and Holocene hydrological episode in the Chad Basin. After a prolonged dry interval, the lake began expanding shortly before 12,000 BP and reached a maximum level with intermittent overflows around 10,000 BP. Its water surface covered at least 400,000 square kilometres. Several recessions followed, around 8,500, 7,500, and 6,500 BP, and the highstand ended about 4,000 BP.
Continue exploring
The Story
The Chad Basin experienced a long interval of desiccation and aeolian activity from somewhat before 21,000 BP until shortly before 12,000 BP. During this phase, dune fields spread across the savanna in a broad belt from the Atlantic coast toward the Nile Valley. The lake then began to expand again as hydrological conditions improved.
Expansion was briefly interrupted a little before 10,300 BP, but subsequently continued. Around 10,000 BP, the lake reached a maximum level and experienced at least intermittent overflows. The water surface covered approximately 400,000 square kilometres, making this one of the most extensive documented late-glacial and Holocene lake expansions in the African interior.
The highstand was not continuous. Recessions occurred around 8,500, 7,500, and 6,500 BP, before the expanded lake phase terminated about 4,000 BP. The sequence records strong hydrological variability in the southern Sahara and Chad Basin and is linked in the passage to changing rainfall across the wider monsoonal belt.