Why Earth continues to remain habitable
Researchers have suggested that geologic cycles act as a climate control, releasing and absorbing atmospheric carbon dioxide in a balance that helps keep Earth planet neither too hot nor too cold.
Mark Torres, a doctoral fellow at the USC Dornsife College of Letters, Arts and Sciences, said that life's presence on Earth is dependent upon this carbon cycle, asserting that this shy it is able to survive.
Torres and Joshua West, professor of Earth Sciences at USC Dornsife, and Gaojun Li of Nanjing University in China, studied rocks taken from the Andes mountain range in Peru and found that weathering processes affecting rocks released far more carbon than previously estimated, which motivated them to consider the global implications of CO2 release during mountain formation.
The researchers noted that rapid erosion in the Andes unearths abundant pyrite — the shiny mineral known as "fool's gold" because of its deceptive appearance — and its chemical breakdown produces acids that release CO2 from other minerals. These observations motivated them to consider the global implications of CO2 release during mountain formation.
Like many other large mountain ranges, such as the great Himalayas, the Andes began to form during the Cenozoic period, which began about 60 million years ago and happened to coincide with a major perturbation in the cycling of atmospheric carbon dioxide.
Using marine records of the long-term carbon cycle, Torres, West, and Gaojun Li of Nanjing University in China, reconstructed the balance between CO2 release and uptake caused by the uplift of large mountain ranges and found that the release of CO2 release by rock weathering may have played a large, but thus far unrecognized, role in regulating the concentration of atmospheric carbon dioxide over the last roughly 60 million years.
The findings have been published in the journal Nature.
(Posted on 20-03-2014)