An international and interdisciplinary team of scientists has discovered a large Eocene transcontinental river system beneath the Antarctic ice that flourished between 44 and 34 million years ago.
The study was published in the journal Science Advances and briefly described by Heritage Daily. The researchers selected and analyzed cores taken from the Amundsen Sea shelf in West Antarctica.
As a result, sediments with layers from two different periods were identified. The oldest dates back to the middle Cretaceous period. It contains traces of fossils, spores and pollen from a temperate rainforest about 85 million years old.
The last upper layer, 34 to 44 million years old, is mainly made up of sand from the middle and late Eocene. Scientists report that they were able to find a relief hidden beneath the ice that resembles the layered structure of a river delta system.
“Biogeochemical data further support this interpretation, as indicated by comparable values with similar settings, suggesting a paleoenvironmental setting receiving significant contributions from river-transported organic and siliciclastic material,” the researchers wrote.
The analysis also showed that the sediments in the second layer may represent remnants of coastal estuarine marshes that were connected by rivers and streams. According to the researchers, the total length of this system could exceed 1,500 kilometers.
