2024-03-29T14:52:01Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/196202018-07-11T09:54:36Zcom_10261_82com_10261_8col_10261_335
Effects of compositional and rheological stratifications on small-scale convection under the oceans: Implications for the thickness of oceanic lithosphere and seafloor flattening
Afonso, Juan Carlos
Zlotnik, Sergio
Fernandez, Manel
Small-scale convection
Oceanic mantle
Geophysical observables
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.
This work was supported by the projects CTM2005-08071-C03-03/MAR and Consolider TopoIberia CSD2006-00041.
Peer reviewed
2009-12-16T13:18:35Z
2009-12-16T13:18:35Z
2008-10
artículo
http://purl.org/coar/resource_type/c_6501
Geophysical Research Letters35: L20308 (2008)
0094-8276
http://hdl.handle.net/10261/19620
10.1029/2008GL035419
en
http://www.agu.org/journals/gl/gl0820/2008GL035419/
none
502670 bytes
application/pdf
American Geophysical Union