thumbnail

Closing of the Midcontinent-Rift - a far-field effect on Grenvillian compression

Geology

By:

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time

Abstract

The Midcontinent rift formed in the Laurentian supercontinent between 1109 and 1094 Ma. Soon after rifting, stresses changed from extensional to compressional, and the central graben of the rift was partly inverted by thrusting on original extensional faults. Thrusting culminated at about 1060 Ma but may have begun as early as 1080 Ma. On the southwest-trending arm of the rift, the crust was shortened about 30km; on the southeast-trending arm, strike-slip motion was dominant. The rift developed adjacent to the tectonically active Grenville province, and its rapid evolution from an extensional to a compressional feature at c1080 Ma was coincident with renewal of northwest-directed thrusting in the Grenville, probably caused by continent-continent collision. A zone of weak lithosphere created by rifting became the locus for deformation within the otherwise strong continental lithosphere. Stresses transmitted from the Grenville province utilized this weak zone to close and invert the rift. -Author

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Closing of the Midcontinent-Rift - a far-field effect on Grenvillian compression
Series title:
Geology
Volume
22
Issue:
2
Year Published:
1994
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
155
Last page:
158
Number of Pages:
4