Escape tectonics and the extrusion of Alaska: Past, present, and future
- 1Geological Survey of Norway, Leiv Eirikssens vei 39, 7491 Trondheim, Norway
- 2Department of Geophysics, Stanford University, Stanford, California 94035, USA, and U.S. Geological Survey, Menlo Park, California 94025, USA
- 3Department of Earth Sciences, Syracuse University, Syracuse, New York 13244, USA
- 4Department of Geology, Western Washington University, Bellingham, Washington 98225, USA
Abstract
The North Pacific Rim is a tectonically active plate boundary zone, parts of which may be characterized as a laterally moving orogenic stream. Crustal blocks are transported along large-magnitude strike-slip faults in western Canada and central Alaska toward the Aleutian–Bering Sea subduction zones. Throughout much of the Cenozoic, at and west of its Alaskan nexus, the North Pacific Rim orogenic Stream (NPRS) has undergone tectonic escape. During transport, relatively rigid blocks acquired paleomagnetic rotations and fault-juxtaposed boundaries while flowing differentially through the system, from their original point of accretion and entrainment toward the free face defined by the Aleutian–Bering Sea subduction zones. Built upon classical terrane tectonics, the NPRS model provides a new framework with which to view the mobilistic nature of the western North American plate boundary zone.
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- Accepted 29 June 2007.
- Received 1 March 2007.
- Revision received 21 June 2007.
- The Geological Society of America, Inc.
