U-Pb geochronology of two pre-Tertiary plutons in the Coast Mountains batholith near Ketchikan, southeastern Alaska
U-Pb geochronologic studies indicate that the central part of the Coast Mountains batholith in the Ketchikan area contains plutons of Triassic and possibly mid-Paleozoic age in addition to the previously recognized early Tertiary plutons. Zircons from a foliated granodiorite in Burroughs Bay yield a...
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1991
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crcansciencepubl:10.1139/e91-081 2023-12-17T10:32:51+01:00 U-Pb geochronology of two pre-Tertiary plutons in the Coast Mountains batholith near Ketchikan, southeastern Alaska Gehrels, George E. Mcclelland, William C. Samson, Scott D. Jackson, Jay L. Patchett, P. Jonathan 1991 http://dx.doi.org/10.1139/e91-081 http://www.nrcresearchpress.com/doi/pdf/10.1139/e91-081 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 28, issue 6, page 894-898 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1991 crcansciencepubl https://doi.org/10.1139/e91-081 2023-11-19T13:38:29Z U-Pb geochronologic studies indicate that the central part of the Coast Mountains batholith in the Ketchikan area contains plutons of Triassic and possibly mid-Paleozoic age in addition to the previously recognized early Tertiary plutons. Zircons from a foliated granodiorite in Burroughs Bay yield an upper concordia intercept of 336 ± 34 Ma, which is tentatively interpreted as the crystallization age, and a lower intercept of 79 ± 7 Ma, which may record extreme Pb loss and growth of metamorphic zircon during amphibolite- to granulite-facies metamorphism. Zircons from a tonalite in Boca de Quadra yield an upper intercept (crystallization age) of 215 ± 15 Ma and a lower intercept (Pb-loss age) of 50 ± 20 Ma. The presence of these Triassic and possibly mid-Paleozoic plutons supports previous interpretations that pre-Tertiary rocks in this part of the batholith may belong to the Yukon-Tanana terrane. Article in Journal/Newspaper Ketchikan Alaska Yukon Canadian Science Publishing (via Crossref) Yukon Canadian Journal of Earth Sciences 28 6 894 898 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Gehrels, George E. Mcclelland, William C. Samson, Scott D. Jackson, Jay L. Patchett, P. Jonathan U-Pb geochronology of two pre-Tertiary plutons in the Coast Mountains batholith near Ketchikan, southeastern Alaska |
topic_facet |
General Earth and Planetary Sciences |
description |
U-Pb geochronologic studies indicate that the central part of the Coast Mountains batholith in the Ketchikan area contains plutons of Triassic and possibly mid-Paleozoic age in addition to the previously recognized early Tertiary plutons. Zircons from a foliated granodiorite in Burroughs Bay yield an upper concordia intercept of 336 ± 34 Ma, which is tentatively interpreted as the crystallization age, and a lower intercept of 79 ± 7 Ma, which may record extreme Pb loss and growth of metamorphic zircon during amphibolite- to granulite-facies metamorphism. Zircons from a tonalite in Boca de Quadra yield an upper intercept (crystallization age) of 215 ± 15 Ma and a lower intercept (Pb-loss age) of 50 ± 20 Ma. The presence of these Triassic and possibly mid-Paleozoic plutons supports previous interpretations that pre-Tertiary rocks in this part of the batholith may belong to the Yukon-Tanana terrane. |
format |
Article in Journal/Newspaper |
author |
Gehrels, George E. Mcclelland, William C. Samson, Scott D. Jackson, Jay L. Patchett, P. Jonathan |
author_facet |
Gehrels, George E. Mcclelland, William C. Samson, Scott D. Jackson, Jay L. Patchett, P. Jonathan |
author_sort |
Gehrels, George E. |
title |
U-Pb geochronology of two pre-Tertiary plutons in the Coast Mountains batholith near Ketchikan, southeastern Alaska |
title_short |
U-Pb geochronology of two pre-Tertiary plutons in the Coast Mountains batholith near Ketchikan, southeastern Alaska |
title_full |
U-Pb geochronology of two pre-Tertiary plutons in the Coast Mountains batholith near Ketchikan, southeastern Alaska |
title_fullStr |
U-Pb geochronology of two pre-Tertiary plutons in the Coast Mountains batholith near Ketchikan, southeastern Alaska |
title_full_unstemmed |
U-Pb geochronology of two pre-Tertiary plutons in the Coast Mountains batholith near Ketchikan, southeastern Alaska |
title_sort |
u-pb geochronology of two pre-tertiary plutons in the coast mountains batholith near ketchikan, southeastern alaska |
publisher |
Canadian Science Publishing |
publishDate |
1991 |
url |
http://dx.doi.org/10.1139/e91-081 http://www.nrcresearchpress.com/doi/pdf/10.1139/e91-081 |
geographic |
Yukon |
geographic_facet |
Yukon |
genre |
Ketchikan Alaska Yukon |
genre_facet |
Ketchikan Alaska Yukon |
op_source |
Canadian Journal of Earth Sciences volume 28, issue 6, page 894-898 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e91-081 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
28 |
container_issue |
6 |
container_start_page |
894 |
op_container_end_page |
898 |
_version_ |
1785586692709679104 |