Cluster of water molecules in garnet from ultrahigh-pressure eclogite
- 1Laboratory of Lithosphere Tectonic Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
- 2China University of Geosciences, Wuhan 430074, China
- 3Laboratory of Lithosphere Tectonic Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
- 4China University of Geosciences, Wuhan 430074, China
Abstract
Through the use of transmission electron microscopy and infrared spectroscopy, hydrous components have been identified as hydroxyl and free water (H2O) in elongate garnet of ultrahigh-pressure eclogite from the Dabie Mountains, eastern China. The H2O occurs as clusters of water molecules and as hydroxyl in garnet; the clusters of water molecules are interpreted to have promoted elongation of garnet through hydrolytic weakening. The presence of hydrous species in ultrahigh-pressure garnet from continental-crust protoliths indicates that such protoliths are able to carry water into the mantle during the subduction of continental lithosphere.
Footnotes
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- Accepted April 9, 2002.
- Received January 13, 2002.
- Revision received March 11, 2002.
- Geological Society of America
