Distribution, facies, ages, and proposed tectonic associations of regionally metamorphosed rocks in Southwestern Alaska and the Alaska Peninsula
Professional Paper
1497-B
Prepared in cooperation with the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys
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- Document: Report (1.04 MB pdf)
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Abstract
The oldest dated metamorphic sequence in Alaska, the fault-bounded Kilbuck Terrane, consists of continental rocks that were metamorphosed under amphibolite-facies conditions during early Proterozoic (1.77 Ga) time. Proterozoic or early Paleozoic metamorphic ages are also possible for greenschist- and amphibolite-facies continental rocks in interior Alaska (Ruby and Nixon Fork terranes). Medium-grade metamorphism on the Alaska Peninsula accompanied intrusion of a Jurassic arc. North of Bristol Bay, low-grade, locally high-pressure Mesozoic metamorphism is attributed to the progressive underthrusting of a subduction complex beneath an oceanic arc followed by underthrusting of the Kilbuck Terrane beneath the subduction complex.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Distribution, facies, ages, and proposed tectonic associations of regionally metamorphosed rocks in Southwestern Alaska and the Alaska Peninsula |
| Series title | Professional Paper |
| Series number | 1497 |
| Chapter | B |
| DOI | 10.3133/pp1497B |
| Year Published | 1996 |
| Language | English |
| Publisher | U.S. Government Printing Office |
| Description | Report: iii, p. B1-B30; 2 Plates: 40 x 54 inches and 40 x 53.5 inches |
| Larger Work Title | Regionally metamorphosed rocks of Alaska |
| Country | United States |
| State | Alaska |
| Google Analytic Metrics | Metrics page |