Seismic data reveal that water level in Lake Malawi, East Africa, was 250 to 500 meters
lower before about 25,000 years ago. Water levels in Lake Tanganyika at that time
were more than 600 meters below the current lake level. A drier climate appears to
have caused these low stands, but tectonic tilting may also have been a contributing
factor in Lake Malawi. High-angle discordances associated with shallow sequence
boundaries suggest that these low stands probably lasted many tens of thousands of
years. Because of its basement topography, the Lake Tanganyika basin had three
separate paleolakes, whereas the Lake Malawi basin had only one. The different
geographies of these paleolakes may be responsible in part for the differences in the
endemic fish populations in these lakes.