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Multiple causes of Earth's earliest global glaciation
Author(s) -
Melezhik Victor A.
Publication year - 2006
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2006.00672.x
Subject(s) - geology , flood basalt , glacial period , basalt , earth science , weathering , context (archaeology) , paleontology , rift , geochemistry , structural basin , volcanism , tectonics
In the context of Earth System evolution, the causal factors driving the Palaeoproterozoic Huronian global glaciations occupy a central position. The rise of O 2 at 2320 Ma, which eliminated most of the methane, was not apparently a single cause triggering the glaciation. At c. 2450 Ma mantle‐plume‐driven continental uplifts led to the emplacement of voluminous continental flood‐basalts in low latitudes that were subsequently dissected by rifting. Major topographical features and continental drainage patterns were most likely similar to those in younger continental flood‐basalt provinces and would have enabled deep weathering and erosion of extensive basalt‐covered continental areas. Intense consumption of atmospheric CO 2 by silicate weathering of fresh basaltic surfaces would have been further amplified by a constant organic carbon burial rate. These factors, similar to those of younger glacial periods, in combination with the diminished CH 4 greenhouse led to an onset of global cooling at the million‐year timescale.