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Tectonics of the Yellowstone hotspot wake in southwestern Montana

William J. Fritz and James W. Sears
Tectonics of the Yellowstone hotspot wake in southwestern Montana
Geology (Boulder) (May 1993) 21 (5): 427-430


Deposits off a Neogene paleovalley provide a geologic datum in southwestern Montana that brackets the age of faulting associated with the Yellowstone hotspot. Ages of paleovalley deposits on top of the modern Blacktail, Ruby, Tendoy, and Centennial ranges and in adjacent valleys range from 16 to 2 Ma. At least 2 km of offset has occurred since emplacement of the Timber Hill basalt (6.0 + or -0.1 Ma); much may have occurred after deposition of the 2.0 Ma Huckleberry Ridge Tuff, which is now found in isolated outcrops as far north as the Ruby Range. Gravel clasts within the paleovalley have a northern provenance, whereas volcanic and volcaniclastic rocks were derived from the Snake River Plain to the south. We propose that uplift associated with passage of the hotspot caused the drainage reversal.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 21
Serial Issue: 5
Title: Tectonics of the Yellowstone hotspot wake in southwestern Montana
Affiliation: Georgia State University, Department of Geology, Atlanta, GA, United States
Pages: 427-430
Published: 199305
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 18
Accession Number: 1993-016430
Categories: Structural geologyStratigraphy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: strat. col., sketch maps
N44°30'00" - N45°00'00", W113°00'00" - W111°00'00"
Secondary Affiliation: University of Montana, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute.
Update Code: 1993
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