9725339 Bruhn A lingering controversy in plate tectonics surrounds the way in which continental crusts interact in collision zones. The arguments center on if and how strain is partitioned among or around several possible crustal blocks. In southeast Alaska the St. Elias collision region includes the largest concentration of high peaks in North America. The conventional explanation for this region is that a continental microplate (the Yakutat block) is converging with the North American plate. An alternative hypothesis holds that slip is partitioned into a strike-slip component and a contractional component allowing a transpressional boundary and that microplates are not involved. This Pavlis and Bruhn study will test these hypotheses by looking for the predictions of the second. In particular, field mapping and structural analysis will be done to evaluate recent an active motion on the predicted strike-slip faults, and examining off-shore seismic reflection data will be analyzed to look for deformation in the predicted off shore fold and thrust belt. The results will bear directly on the resolving the controversy here in Alaska, but will also reveal generic results that will allow generalizing about the behavior of transpressive plate boundaries in general.

Agency
National Science Foundation (NSF)
Institute
Division of Earth Sciences (EAR)
Application #
9725339
Program Officer
Arthur G. Goldstein
Project Start
Project End
Budget Start
1998-03-01
Budget End
2002-02-28
Support Year
Fiscal Year
1997
Total Cost
$157,847
Indirect Cost
Name
University of Utah
Department
Type
DUNS #
City
Salt Lake City
State
UT
Country
United States
Zip Code
84112