Title of article :
Metamorphic decarbonation in the Neoproterozoic and its environmental implication
Author/Authors :
Omori، نويسنده , , S. and Santosh، نويسنده , , M.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2008
Pages :
8
From page :
97
To page :
104
Abstract :
Metamorphic decarbonation reactions and volcanic degassing lead to significant influx of CO2, a major greenhouse gas, into the ocean-atmosphere system from the solid Earth. Here we present quantitative estimates on CO2 derived through metamorphic degassing during ultrahigh-temperature (UHT) metamorphism in the Neoproterozoic through the mineralogical and geological analyses of the UHT decarbonation. Our computations show that an extra flux of CO2 was added to the atmosphere through a Himalayan scale UHT metamorphism to the extent of 6 × 1016 to 3.0 × 1018 mol/my, for a duration of 10 my. A calculation of the impact of the extra CO2 influx to the global mean temperature in the context of carbon cycle and greenhouse effect of CO2 shows that at the peak influx stage, the steady state temperature would be raised by 4 °C from 15 °C and by 13 °C from 4 °C. Our results have important bearing in evaluating the mechanism of melting and the duration of the Snowball Earth. Our estimate of the maximum degassing rate during UHT metamorphism suggests that the duration of the Marinoan snowball Earth was probably shorter, and the recovery from an ice-covered Earth to ocean-covered Earth was faster than previous estimates.
Keywords :
CO2 , Ultrahigh-temperature metamorphism , carbon cycle , Greenhouse gas , Snowball Earth , Neoproterozoic
Journal title :
Gondwana Research
Serial Year :
2008
Journal title :
Gondwana Research
Record number :
2363665
Link To Document :
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