Eight thousand year old cave paintings in the Sahara have helped scientists identify ancient lake beds.

The prehistoric paintings in the Cave of Swimmers, discovered by the Hungarian explorer Laszlo Almasy in 1933, depict figures that appear to be swimming and diving - although literal interpretations often compete with metaphorical interpretations - despite their location in south-western Egypt in a desert environment. Scientists, however, have now discovered mineral remnants in this region.

This supports the idea that the climate was much wetter and the Sahara much greener, which makes sense of the wild life, such as giraffes and cattle, also depicted in the rock art as paintings and petroglyphs. This earlier wetter climate, according to the researchers Chris McKay from the NASA Ames Research Center, Margarita Marinova from the Bay Area Environmental Research Institute and Nele Meckler of ETH Zurich , is now believed to be much more recent than previously thought.

Carbonate deposits on rock faces in the Gebel Uweinat region, just south of the Cave of the Swimmers, would have been formed in shallow water along a lake shoreline. From carbon dating, the researchers estimate that at least two lakes existed between 8,100 and 9,400 years ago. This seems to coincide with the age of the rock art.

To read more about the Cave of swimmers:

http://www.bradshawfoundation.com/africa/gilf_kebir_cave_of_swimmers/index.php