Possible emplacement of crustal rocks into the forearc mantle of the Cascadia Subduction Zone Public Deposited

http://ir.library.oregonstate.edu/concern/defaults/g158bp60g

Copyrighted by American Geophysical Union.

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • Seismic reflection profiles shot across the Cascadia forearc show that a 5–15 km thick band of reflections, previously interpreted as a lower crustal shear zone above the subducting Juan de Fuca plate, extends into the upper mantle of the North American plate, reaching depths of at least 50 km. In the extreme western corner of the mantle wedge, these reflectors occur in rocks with P wave velocities of 6750–7000 ms⁻¹. Elsewhere, the forearc mantle, which is probably partially serpentinized, exhibits velocities of approximately 7500 ms⁻¹. The rocks with velocities of 6750–7000 ms⁻¹ are anomalous with respect to the surrounding mantle, and may represent either: (1) locally high mantle serpentinization, (2) oceanic crust trapped by backstepping of the subduction zone, or (3) rocks from the lower continental crust that have been transported into the uppermost mantle by subduction erosion. The association of subparallel seismic reflectors with these anomalously low velocities favours the tectonic emplacement of crustal rocks.
Resource Type
DOI
Date Available
Date Issued
Citation
  • Calvert, A. J., M. A. Fisher, K. Ramachandran, and A. M. Tre´hu, Possible emplacement of crustal rocks into the forearc mantle of the Cascadia Subduction Zone, Geophys. Res. Lett., 30(23), 2196, 2003.
Rights Statement
Publisher
Replaces
Additional Information
  • description.provenance : Made available in DSpace on 2010-04-26T21:43:01Z (GMT). No. of bitstreams: 1 Calvert et al GRL 2003.pdf: 456457 bytes, checksum: c83e495e90690c27b34d836edc16b811 (MD5) Previous issue date: 2003-12-05
  • Geophysical Research Letters
  • Vol. 30 No. 23 (2003)
  • description.provenance : Approved for entry into archive by Linda Kathman(linda.kathman@oregonstate.edu) on 2010-04-26T21:43:01Z (GMT) No. of bitstreams: 1 Calvert et al GRL 2003.pdf: 456457 bytes, checksum: c83e495e90690c27b34d836edc16b811 (MD5)
  • description.provenance : Submitted by David Moynihan (dmscanner@gmail.com) on 2010-04-26T19:55:04Z No. of bitstreams: 1 Calvert et al GRL 2003.pdf: 456457 bytes, checksum: c83e495e90690c27b34d836edc16b811 (MD5)

Relationships

In Administrative Set:
Last modified: 12/07/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items