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Biotic enhancement of weathering, atmospheric oxygen and carbon dioxide in the Neoproterozoic
Author(s) -
Lenton Timothy M.,
Watson Andrew J.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl018802
Subject(s) - weathering , geology , carbon dioxide in earth's atmosphere , silicate , carbon dioxide , earth science , geologic record , atmosphere (unit) , atmospheric oxygen , flux (metallurgy) , carbon fibers , geochemistry , astrobiology , oceanography , oxygen , climate change , ecology , chemistry , physics , materials science , organic chemistry , composite number , composite material , biology , thermodynamics
It has been suggested that biological colonization of the land surface began in the Neoproterozoic 1000–544 million years ago (Ma). We hypothesize that this colonization involved selective weathering of P from rocks, as well as an amplification of overall weathering rates. We show that two recent models, despite differences in the feedback mechanisms represented, predict that an increase in the weathering flux of P to the ocean would have caused a rise in atmospheric O 2 in the Neoproterozoic. This in turn may have provided a necessary condition for the evolution of animals with hard skeletons seen in the ‘Cambrian explosion’. Increased weathering of silicate rocks would also have caused a decline in atmospheric CO 2 , which could have been a causal factor in the Neoproterozoic glaciations.