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Archean komatiites and geotherms: Solution to an apparent contradiction
Author(s) -
Jarvis Gary T.,
Campbell Ian H.
Publication year - 1983
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/gl010i012p01133
Subject(s) - archean , geology , mantle (geology) , geothermal gradient , mantle convection , subduction , geochemistry , early earth , igneous rock , petrology , geophysics , earth science , paleontology , tectonics
The high liquidus temperatures of Archean komatiites and the low geothermal gradients in Archean continents appear to give contradictory indications of temperatures in the Archean mantle. We resolve this contradiction in terms of an idealized model of convection in the Archean mantle. We suggest that temperatures in the Archean mantle were no more than 100°C higher than at present, that komatiites originate from the hot lower boundary layer of a non‐steady convection cell and that Archean continents were formed near subduction zones where near‐surface temperature gradients were lower than elsewhere in the convecting mantle.