Interrelations between intermediate-depth earthquakes and fluid flow within subducting oceanic plates: Constraints from eclogite facies pseudotachylytes
- 1Institut für Geowissenschaften and SFB 574, Universität Kiel, Olshausenstrasse 40, 24098 Kiel, Germany
Abstract
Field evidence preserved in ancient subducted oceanic crust documents that eclogite facies frictional failure with melting (pseudotachylyte formation during intermediate-depth earthquakes) was accompanied and followed, not preceded, by infiltration of external fluids and progressive vein formation in the eclogites. Eclogitization began during seismic failure and fluid passage through the shear zone. Subsequent fluid flow produced hydraulic fracturing and continuous vein formation during ongoing burial. We suggest that this kind of shear zone may allow channelized fluid flow within and out of slabs.
- pseudotachylyte
- intermediate-depth earthquake
- eclogite facies
- oceanic crust
- subduction zone
- fluid flow
Footnotes
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↵*tj{at}min.uni-kiel.de
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↵GSA Data Repository item 2006107, Tables DR1–DR2 and Figures DR1–DR2, is available online at www.geosociety.org/pubs/ft2006.htm, or on request from editing{at}geosociety.org or Documents Secretary, GSA, P.O. Box 9140, Boulder, CO 80301, USA.
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- Accepted 16 February 2006.
- Received 8 November 2005.
- Revision received 15 February 2006.
- The Geological Society of America, Inc.
