Provenance of the Chugach-Prince William terrane through U/Pb dating of detrital zircons, Baranof Island, SE Alaska
The southern Alaska continental margin contains the Chugach-Prince William Terrane (CPW), a ~2200 km Mesozoic-Tertiary accretionary complex composed mainly of deep-water turbidites and is intruded by 62-47 Ma near trench plutons of the Sanak- Baranof Belt (SBB). Location of the CPW during intrusion...
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ftcarletoncoll:oai:digitalcommons.carleton.edu:comps-1793 2024-02-11T10:05:34+01:00 Provenance of the Chugach-Prince William terrane through U/Pb dating of detrital zircons, Baranof Island, SE Alaska Rick, Brianna Joy 2014-01-01T08:00:00Z application/pdf https://digitalcommons.carleton.edu/comps/794 unknown Carleton Digital Commons https://digitalcommons.carleton.edu/comps/794 Integrated Comprehensive Exercises (Comps) detrital zircon Chugach-Prince William terrane Sitka Graywacke U/Pb geochronology maximum depositional age provenance text 2014 ftcarletoncoll 2024-01-22T19:20:24Z The southern Alaska continental margin contains the Chugach-Prince William Terrane (CPW), a ~2200 km Mesozoic-Tertiary accretionary complex composed mainly of deep-water turbidites and is intruded by 62-47 Ma near trench plutons of the Sanak- Baranof Belt (SBB). Location of the CPW during intrusion has been proposed to have occurred either 1) near its current latitude, interacting with the migrating Kula- Ressurection TRT triple junction, or 2) at a southern latitude, interacting with the fixed Kula-Farallon TRT triple junction while migrating northward. This paper presents U/Pb detrital zircon data (n=725) from the Sitka Graywacke and its metamorphic equivalent, the Baranof Schist, on southern Baranof Island in an effort to better understand correlations along strike across the CPW. Maximum depositional ages (MDA) reveal an inboard to outboard (NE to SW) younging progression from ~100 Ma to ~60 Ma, suggesting nearly continuous deposition. The Sitka Graywacke can be packaged into three groups younging inboard to outboard: A) an inboard Albian belt deposited 95-105 Ma, B) an intermediate Campanian-Maastrichtian Belt deposited 65-75 Ma, C) an outboard Paleocene belt deposited 60-65 Ma. U/Pb detrital zircon data show that the youngest and most outboard Paleocene belt (60-65 Ma) on Baranof Island correlates to the Whale Bay belt (60-69 Ma) of the Orca Group in Prince William Sound. Composite detrital zircon data from the Shumigan Islands, Kodiak Island, Seward, Prince William Sound, and Baranof Island reinforce along-strike correlations across the CPW. These sites have a significant 1800-2000 Ma Precambrian grain age population, suggesting a Northern Laurentian signal for the CPW extending to Baranof Island. These data support the restoration of the Yakutat microplate, with a Southern Laurentian signal, south of Baranof Island. Text Kodiak Orca Yakutat Alaska Carleton College: Digital Commons Whale Bay ENVELOPE(69.360,69.360,-49.131,-49.131) |
institution |
Open Polar |
collection |
Carleton College: Digital Commons |
op_collection_id |
ftcarletoncoll |
language |
unknown |
topic |
detrital zircon Chugach-Prince William terrane Sitka Graywacke U/Pb geochronology maximum depositional age provenance |
spellingShingle |
detrital zircon Chugach-Prince William terrane Sitka Graywacke U/Pb geochronology maximum depositional age provenance Rick, Brianna Joy Provenance of the Chugach-Prince William terrane through U/Pb dating of detrital zircons, Baranof Island, SE Alaska |
topic_facet |
detrital zircon Chugach-Prince William terrane Sitka Graywacke U/Pb geochronology maximum depositional age provenance |
description |
The southern Alaska continental margin contains the Chugach-Prince William Terrane (CPW), a ~2200 km Mesozoic-Tertiary accretionary complex composed mainly of deep-water turbidites and is intruded by 62-47 Ma near trench plutons of the Sanak- Baranof Belt (SBB). Location of the CPW during intrusion has been proposed to have occurred either 1) near its current latitude, interacting with the migrating Kula- Ressurection TRT triple junction, or 2) at a southern latitude, interacting with the fixed Kula-Farallon TRT triple junction while migrating northward. This paper presents U/Pb detrital zircon data (n=725) from the Sitka Graywacke and its metamorphic equivalent, the Baranof Schist, on southern Baranof Island in an effort to better understand correlations along strike across the CPW. Maximum depositional ages (MDA) reveal an inboard to outboard (NE to SW) younging progression from ~100 Ma to ~60 Ma, suggesting nearly continuous deposition. The Sitka Graywacke can be packaged into three groups younging inboard to outboard: A) an inboard Albian belt deposited 95-105 Ma, B) an intermediate Campanian-Maastrichtian Belt deposited 65-75 Ma, C) an outboard Paleocene belt deposited 60-65 Ma. U/Pb detrital zircon data show that the youngest and most outboard Paleocene belt (60-65 Ma) on Baranof Island correlates to the Whale Bay belt (60-69 Ma) of the Orca Group in Prince William Sound. Composite detrital zircon data from the Shumigan Islands, Kodiak Island, Seward, Prince William Sound, and Baranof Island reinforce along-strike correlations across the CPW. These sites have a significant 1800-2000 Ma Precambrian grain age population, suggesting a Northern Laurentian signal for the CPW extending to Baranof Island. These data support the restoration of the Yakutat microplate, with a Southern Laurentian signal, south of Baranof Island. |
format |
Text |
author |
Rick, Brianna Joy |
author_facet |
Rick, Brianna Joy |
author_sort |
Rick, Brianna Joy |
title |
Provenance of the Chugach-Prince William terrane through U/Pb dating of detrital zircons, Baranof Island, SE Alaska |
title_short |
Provenance of the Chugach-Prince William terrane through U/Pb dating of detrital zircons, Baranof Island, SE Alaska |
title_full |
Provenance of the Chugach-Prince William terrane through U/Pb dating of detrital zircons, Baranof Island, SE Alaska |
title_fullStr |
Provenance of the Chugach-Prince William terrane through U/Pb dating of detrital zircons, Baranof Island, SE Alaska |
title_full_unstemmed |
Provenance of the Chugach-Prince William terrane through U/Pb dating of detrital zircons, Baranof Island, SE Alaska |
title_sort |
provenance of the chugach-prince william terrane through u/pb dating of detrital zircons, baranof island, se alaska |
publisher |
Carleton Digital Commons |
publishDate |
2014 |
url |
https://digitalcommons.carleton.edu/comps/794 |
long_lat |
ENVELOPE(69.360,69.360,-49.131,-49.131) |
geographic |
Whale Bay |
geographic_facet |
Whale Bay |
genre |
Kodiak Orca Yakutat Alaska |
genre_facet |
Kodiak Orca Yakutat Alaska |
op_source |
Integrated Comprehensive Exercises (Comps) |
op_relation |
https://digitalcommons.carleton.edu/comps/794 |
_version_ |
1790602642443993088 |