Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Geology Email Content Delivery
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Geology; May 2005; v. 33; no. 5; p. 385-388; DOI: 10.1130/G21273.1
© 2005 Geological Society of America
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Mahan, K.H.
Right arrow Articles by Williams, M.L.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Reconstruction of a large deep-crustal terrane: Implications for the Snowbird tectonic zone and early growth of Laurentia

K.H. Mahan*,1 and M.L. Williams1

1 Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA

The ~2800-km-long Snowbird tectonic zone is a well-recognized but still enigmatic feature in the western Canadian Shield. It has been interpreted as a Paleoproterozoic continental suture or an Archean strike-slip fault system, but here we suggest that the distinctive geometry of the central Snowbird tectonic zone is primarily due to the interaction of crosscutting Paleoproterozoic intracontinental thrust and strike-slip shear zones having a length of hundreds of kilometers. First, a major zone of thrust-sense shearing, coeval with early continent-continent collision between the Superior and western Churchill provinces, accommodated uplift of a large exposure of granulite facies lower continental crust. Younger strike-slip shear zones, perhaps analogous to Asian fault systems behind the Himalayan orogen, offset the thrust zone. Thus, the current geometry and distribution of deep-crustal rocks in this region represent a relatively late stage in the tectonic evolution of the western Churchill province rather than an accretionary one. Earlier structures oriented at a high angle to the Snowbird tectonic zone may record the fundamental accretionary history in this part of Laurentia.

Key Words: shear zones • deep crust • intracontinental • exhumation • Canadian Shield




This article has been cited by other articles:


Home page
 GeologyHome page
R.G. Berman, W.J. Davis, and S. Pehrsson
Collisional Snowbird tectonic zone resurrected: Growth of Laurentia during the 1.9 Ga accretionary phase of the Hudsonian orogeny
Geology, October 1, 2007; 35(10): 911 - 914.
[Abstract] [Full Text] [PDF]

Home page
 Geological Society of America BulletinHome page
G. Dumond, K. H. Mahan, M. L. Williams, and K. E. Karlstrom
Crustal segmentation, composite looping pressure-temperature paths, and magma-enhanced metamorphic field gradients: Upper Granite Gorge, Grand Canyon, USA
Geological Society of America Bulletin, January 1, 2007; 119(1-2): 202 - 220.
[Abstract] [Full Text] [PDF]

Home page
 South African Journal of GeologyHome page
S. Master
Pangaean megalineaments: geophysical indications for the existence of Laurentian counterparts of the 6000 km Trans-Saharan Tibesti Lineament, and implications for lithospheric tectonics and mineral deposits
South African Journal of Geology, December 1, 2006; 109(4): 503 - 514.
[Abstract] [Full Text] [PDF]


JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Geological Society of America