The Congo Basin – with its massive, lush tropical rain forest – was far different 150 million to 200 million years ago.
At that time Africa and South America were part of the single continent Gondwana. The Congo Basin was arid, with a small amount of seasonal rainfall, and few bushes or trees populated the landscape, according to a new geochemical analysis of rare ancient soils.
The geochemical analysis provides new data for the Jurassic period, when very little is known about central Africa’s paleoclimate, says Timothy Myers, a paleontology doctoral student in SMU’s Huffington Department of Earth Sciences, Dedman College.
There aren’t a whole lot of terrestrial deposits from that time period preserved in Central Africa,” Myers says. “Scientists have been looking at Africa’s paleoclimate for some time, but data from this time period is unique.”
There are several reasons for the scarcity of deposits: Ongoing armed conflict makes it difficult and challenging to retrieve them; and the thick vegetation, a humid climate and continual erosion prevent the preservation of ancient deposits, which would safeguard clues to Africa’s paleoclimate.
Myers’ research is based on a core sample drilled by a syndicate interested in the oil and mineral deposits in the Congo Basin. Myers accessed the sample – drilled from a depth of more than 2 kilometers – from the Royal Museum for Central Africa in Tervuren, Belgium, where it is housed. With the permission of the museum, he analyzed pieces of the core at the SMU Huffington Department of Earth Science’s Isotope Laboratory.
“I would love to look at an outcrop in the Congo,” Myers says, “but I was happy to be able to do this.” (Above, an ancient soil crack, called a clastic dike, produced by alternate wetting and drying cycles from seasonal rainfall.)