Academic Commons

Articles

Age of oceanic plates at subduction and volatile recycling

Abbott, Dallas Helen; Lyle, Mitchell

The age of the subducting plate as it enters the trench controls the maximum depth of volatile transport by the downgoing plate. As the slab descends and heats up, decarbonation and dehydration reactions cause alteration minerals and sediments to release volatiles. Our calculations show that subducting oceanic plates <11 m.y. old in oceanic arcs and <34 m.y. old in continental arcs heat up so rapidly that no H2O or CO2 can return to the asthenosphere. Instead, these volatiles rise into the over-riding lithospheric plate. CO2 and H2O are released differently during subduction. A thickly-sedimented plate subducting beneath an oceanic arc will return H2O to the asthenosphere only if the subducting plate is older than 11 m.y. and CO2 only if it is older than 25 m.y. If Archaean oceanic lithosphere had a maximum age of 30-50 m.y. and an average age of 10-18 m.y., then the amount of volatile recycling to the asthenosphere could have been much lower than at present, despite a greater total consumption rate.

Files

  • thumnail for Abbott_et_al-1984-Geophysical_Research_Letters__1_.pdf Abbott_et_al-1984-Geophysical_Research_Letters__1_.pdf application/pdf 324 KB Download File

Also Published In

Title
Geophysical Research Letters
DOI
https://doi.org/10.1029/GL011i010p00951

More About This Work

Academic Units
Lamont-Doherty Earth Observatory
Publisher
American Geophysical Union
Published Here
January 21, 2016
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.