Effects of compositional and rheological stratifications on small-scale convection under the oceans : implications for the thickness of oceanic lithosphere and seafloor flattening | Macquarie University ResearchOnline

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Effects of compositional and rheological stratifications on small-scale convection under the oceans : implications for the thickness of oceanic lithosphere and seafloor flattening

Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.14/91178

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Title: Effects of compositional and rheological stratifications on small-scale convection under the oceans : implications for the thickness of oceanic lithosphere and seafloor flattening
Related: Geophysical research letters, Vol. 35, (2008), p.L20308-1-L20308-5
DOI: 10.1029/2008GL035419
Publisher: American Geophysical Union
Date: 2008
FoR/RFCD Code(s): 040400 Geophysics
Author/Creator: Afonso, J. C
Author/Creator: Zlotnik, S
Author/Creator: Fernàndez, M
Description: Pressure‐release melting at mid‐ocean ridges generate compositional and rheological layering in the oceanic mantle that may control the evolution of the oceanic lithosphere. We use dynamic models coupled with melting and petrological models to explore 1) the influence of this layering on the development of small‐scale convection under the oceans, 2) its role in determining the thickness of oceanic lithosphere, and 3) its feasibility as responsible for the deviations of seafloor and surface heat flow from predictions by conductive models in mature oceanic lithosphere. Here we show that the existence of small‐scale convection is entirely compatible with experimental creep parameters and flow laws, and that the viscosity stratification due to melt extraction (i.e., H₂O removal) is the main factor controlling the plate's thermal evolution, its asymptotic thickness, and the flattening of seafloor and surface heat flow at ages ≳70 Ma. The effects of Al‐rich phase transitions and compositional layering are minor.
Description: 5 page(s)
Subject Keyword: 040400 Geophysics
Subject Keyword: small-scale convection
Subject Keyword: oceanic mantle
Subject Keyword: geophysical observables
Resource Type: journal article
Organisation: Macquarie University. National Key Centre for Geochemical Evolution and Metallogeny of Continents (GEMOC)

Identifier: http://hdl.handle.net/1959.14/91178
Identifier: ISSN:0094-8276
Identifier: mq-rm-2009001548
Language: eng
Rights: Copyright American Geophysical Union (AGU) 2008. Originally published in Geophysical research letters, Vol. 35, L20308. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.
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