Evidence for two pulses of glaciation during the late Proterozoic in northern Utah and southeastern Idaho

Geological Society of America Bulletin
By: , and 

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Abstract

Over much of this area, the glacial deposits and associated rocks thicken westward and form the basal part of a miogeoclinal wedge that accumulated near the late Proterozoic and early Paleozoic continental margin. In the east, such deposits are thin and rest on Archean basement or rocks of Proterozoic Y age; in the west, they are part of thicker sequences in which deposition apparently continued without significant interruption from late Proterozoic into Cambrian time. Recent mapping shows that glacial episodes represented either by diamictite or by dropstones enclosed in fine-grained laminated beds are separated by as much as 1000m of non-glacial deposits, including black slate, alternating graywacke and siltstone, quartzite, and conglomerate. Using reasonable sedimentation rates for such deposits and by comparison with modern analogues, we infer that two episodes of glaciation, each probably consisting of multiple advances and retreats, were separated by a non-glacial interval of a few hundred thousand to a few million years' duration.-from Author

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Evidence for two pulses of glaciation during the late Proterozoic in northern Utah and southeastern Idaho
Series title Geological Society of America Bulletin
DOI 10.1130/0016-7606(1983)94<437:EFTPOG>2.0.CO;2
Volume 94
Issue 4
Year Published 1983
Language English
Publisher Geological Society of America
Description 14 p.
First page 437
Last page 450
Country United States
State Idaho, Utah
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