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Detrital mineral chronology of the Uinta Mountain Group: Implications for the Grenville flood in southwestern Laurentia

Geology

By:
, , , , , and
DOI: 10.1130/G23148A.1

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Abstract

Numerous studies have shown that large quantities of Grenville-age detritus dominate Neo-proterozoic to Cambrian arenites in southwest Laurentia (southwestern United States). U-Pb ages and Hf isotopic compositions of zircons and 40Ar/39Ar ages of white mica from clastic sedimentary rocks of the Neoproterozoic Uinta Mountain Group also indicate significant Mesoproterozoic detritus mixed with a variably abundant Archean component. Zircons with ages representative of the Paleoproterozoic basement in the eastern Uinta Mountains or the younger Paleoproterozoic rocks of the adjacent Yavapai-Mazatzal terranes were not observed. A limited range of initial ??Hf (???90% between -3 and +3) for Mesoproterozoic zircons suggests derivation from a source region (or regions) characterized by mixing between juvenile and reworked older crust during Grenville orogenesis. The enriched Grenville-age basement proposed to underlie much of southeastern North America may be this source based on similarities of Hf isotopic data from Mesoproterozoic zircons in Mississippi River sand and available paleocurrent data. If so, then disruption of this supply in the Cambrian may be related to Iapetan rifting and, perhaps, the separation of the Precordillera terrane from Laurentia. ?? 2007 The Geological Society of America.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Detrital mineral chronology of the Uinta Mountain Group: Implications for the Grenville flood in southwestern Laurentia
Series title:
Geology
DOI:
10.1130/G23148A.1
Volume
35
Issue:
5
Year Published:
2007
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geology
First page:
431
Last page:
434
Number of Pages:
4