CaltechAUTHORS
  A Caltech Library Service

Water and magma generation at subduction zones

Wyllie, P. J. (1978) Water and magma generation at subduction zones. Bulletin Volcanologique, 41 (4). pp. 360-377. ISSN 0366-483X. https://resolver.caltech.edu/CaltechAUTHORS:20160129-080231674

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20160129-080231674

Abstract

The basaltic ocean crust, metasomatized and metamorphosed during and after generation at the ocean ridge, contains H_2O stored in minerals and pore fluid. Phase equilibrium data establish the conditions for dehydration, and the conditions for melting of amphibole-gabbro or amphibole-quartz-eclogite, or for quartz-eclogite or mantle peridotite if aqueous fluids are available. But there is no concensus about the temperature distribution through the subducted crust, or within the overlying mantle wedge. Therefore, a variety of magmatic models can be derived from the experimental data. According to some calculations, endothermic dehydration reactions in the depth interval 75–125 km cool the oceanic crust to such an extent that it cannot be a major source of magmas; instead, concentrated aqueous fluids released from the crust generate magmas in the overlying peridotite. However, according to most existing thermal models, if temperatures in ocean crust are cool enough to prohibit melting of amphibolite, then temperatures in the mantle above the main sources of expelled fluids are too low for hydrous melting. The ocean crust appears to be effectively dehydrated by 100–125 km depth. Dense hydrous magnesian silicates are not likely candidates for deeper H_2O transport. The extent to which H_2O can be fixed in metasomatic phlogopite in crust or mantle is a significant but undetermined factor. Experimental data on minerals and liquid compositions do not support the concept of primary magmas for andesites and associated lavas from mantle or subducted crust. Complex, multi-stage processes appear to be more likely, which is consistent with recent interpretations of geochemical data.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1007/BF02597371DOIArticle
http://link.springer.com/article/10.1007%2FBF02597371PublisherArticle
Additional Information:© 1978 Springer International Publishing AG. This research was supported by the Earth Sciences Section, National Science Foundation, by Grant EAR 76-20413.
Funders:
Funding AgencyGrant Number
NSFEAR 76-20413
Issue or Number:4
Record Number:CaltechAUTHORS:20160129-080231674
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20160129-080231674
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:64075
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:29 Jan 2016 20:18
Last Modified:03 Oct 2019 09:34

Repository Staff Only: item control page