Metamorphic rocks of the Yakutat-St. Elias area, south-central Alaska

Journal of Research of the U.S. Geological Survey
By: , and 

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Abstract

Metamorphic rocks in the Yakutat-St. Elias area range in grade from zeolite to amphibolite facies. Radiometric age determinations on selected metamorphic rocks have helped to identify two major metamorphic events, one in Late Cretaceous time that was characterized by penetrative deformation, and one in the Miocene Epoch that resulted in widespread recrystallization and igneous intrusions. Mapped facies units show many discontinuities across major faults, and their distribution indicates major differential uplift between several structurally bound crustal blocks within a strongly deformed mobile belt west of the Art Lewis fault. Late Cretaceous metamorphic gradients indicate that the blocks have been tilted to the west or northwest parallel to their general structural grain. As mineral assemblages that were recrystallized during Miocene time occur on both sides of the Fairweather fault, large-scale, post-Miocene strike-slip movement along the fault is not indicated.

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Publication type Article
Publication Subtype Journal Article
Title Metamorphic rocks of the Yakutat-St. Elias area, south-central Alaska
Series title Journal of Research of the U.S. Geological Survey
Volume 5
Issue 2
Year Published 1977
Language English
Publisher U. S. Geological Survey
Description 12 p.
First page 173
Last page 184
Country United States
State Alaska
Other Geospatial St. Elias, Yakutat
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