The Open Mineralogy Journal

2007, 1 : 1-4
Published online 2007 August 20. DOI: 10.2174/18744567000701010001
Publisher ID: TOMJ-1-1

The Lehmann Discontinuity Due to Dehydration of Subducted Sediment

Shigeaki Ono
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK.

ABSTRACT

Recent high-pressure experiments have led to the conclusion that water release from subducted sediments lying under continents in subduction regions occurs at about 220 km depth. This dehydration reaction is in good agreement with the seismological signature of the discontinuity indicating that sediment dehydration causes the Lehmann discontinuity in the upper mantle.

Keywords:

Lehmann discontinuity, high pressure, water.