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Geochronometric and lead isotope data on samples from the Wallace 1 degree by 2 degrees Quadrangle, Montana and Idaho

Miscellaneous Field Studies Map 1354-G
By: , and 

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Abstract

Most of the bedrock in the Wallace quadrangle belongs to the Belt Supergroup, a thick (about 18,000 m) sequence of generally fine-grained clastic and carbonate rocks of Middle Proterozoic age.  Regional metamorphism prior to Cambrian time prograded the Belt rocks to greenschist facies, and some metal-bearing veins were emplaced in fractures.  The Belt rocks were intruded in Late Proterozoic time by basic dikes and sills.

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Publication type Report
Publication Subtype USGS Numbered Series
Title Geochronometric and lead isotope data on samples from the Wallace 1 degree by 2 degrees Quadrangle, Montana and Idaho
Series title Miscellaneous Field Studies Map
Series number 1354
Chapter G
DOI 10.3133/mf1354G
Year Published 1984
Language English
Publisher U.S. Geological Survey
Description 31.43 x 41.26 inches
Country United States
State Idaho, Montana
Scale 250000
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