TY - JOUR
T1 - Effects of compositional and rheological stratifications on small-scale convection under the oceans
T2 - Implications for the thickness of oceanic lithosphere and seafloor flattening
AU - Afonso, J. C.
AU - Zlotnik, S.
AU - Fernàndez, M.
N1 - 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.
PY - 2008/10/28
Y1 - 2008/10/28
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=58249088901&partnerID=8YFLogxK
U2 - 10.1029/2008GL035419
DO - 10.1029/2008GL035419
M3 - Article
AN - SCOPUS:58249088901
SN - 0094-8276
VL - 35
SP - 1
EP - 5
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 20
M1 - L20308
ER -