Tectonic Evolution of the Northern Margin of North America
The northern margin of North America records a protracted history of Neoproterozoic–early Paleozoic rifting and passive margin development, followed by the middle Paleozoic accretion of continental fragments. Contrasting tectonic models have been proposed for the history of continent separation, the...
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ftdartmouthcoll:oai:digitalcommons.dartmouth.edu:dissertations-1144 2023-10-01T03:53:48+02:00 Tectonic Evolution of the Northern Margin of North America Faehnrich, Karol 2023-03-13T07:00:00Z application/pdf https://digitalcommons.dartmouth.edu/dissertations/154 https://digitalcommons.dartmouth.edu/context/dissertations/article/1144/viewcontent/Faehnrich_PhD_Thesis.pdf unknown Dartmouth Digital Commons https://digitalcommons.dartmouth.edu/dissertations/154 https://digitalcommons.dartmouth.edu/context/dissertations/article/1144/viewcontent/Faehnrich_PhD_Thesis.pdf Dartmouth College Ph.D Dissertations Tectonics Geology of North America strike-slip geochronology stratigraphy Alaska Yukon Ellesmere Island Geology Tectonics and Structure text 2023 ftdartmouthcoll 2023-09-03T16:58:18Z The northern margin of North America records a protracted history of Neoproterozoic–early Paleozoic rifting and passive margin development, followed by the middle Paleozoic accretion of continental fragments. Contrasting tectonic models have been proposed for the history of continent separation, the role of strike-slip displacement during terrane accretion, and the Mesozoic opening of the Arctic Ocean. Here, I explore several of these models by investigating Neoproterozoic–early Paleozoic sedimentary and volcanic rocks across the northern margin of North American, as well as the main faulted boundaries between displaced terranes and autochthonous rocks of North America. First, I present a new tectonic model for late Ediacaran to early Cambrian rifting recorded in volcanic and sedimentary rocks of the Yelverton Formation exposed on northern Ellesmere Island, Canada. I constrain the timing of volcanism to ~570-530 Ma and relate it to decompression melting during progressive rifting. I suggest that rifting led to the separation of the North Slope subterrane of Arctic Alaska from the Laurentian margin. Second, I reconstruct the complex stratigraphy within the Porcupine Fault System, which marks the current tectonic boundary between the North Slope subterrane and the autochthonous Yukon block. I define a new succession of late Tonian sedimentary deposits, named the Ch’oodeenjìk succession. I suggest it represents a unique peri-Laurentian crustal fragment displaced along the Porcupine Fault System. Finally, I integrate detailed geological mapping with various thermochronometric and geochronometric techniques to determine the displacement history within the Porcupine Fault System. A new ca. 119 Ma U/Pb date on a calcite vein within the fault system highlights an episode of Early Cretaceous deformation, supporting models that involve terrane translation rather than rotation during the formation of the Canada Basin of the Arctic Ocean. Together, I propose that the northern margin of North America was characterized by ... Text Arctic Arctic Ocean canada basin Ellesmere Island north slope Alaska Yukon Dartmouth Digital Commons (Dartmouth College) Arctic Arctic Ocean Yukon Ellesmere Island Canada |
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Open Polar |
collection |
Dartmouth Digital Commons (Dartmouth College) |
op_collection_id |
ftdartmouthcoll |
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unknown |
topic |
Tectonics Geology of North America strike-slip geochronology stratigraphy Alaska Yukon Ellesmere Island Geology Tectonics and Structure |
spellingShingle |
Tectonics Geology of North America strike-slip geochronology stratigraphy Alaska Yukon Ellesmere Island Geology Tectonics and Structure Faehnrich, Karol Tectonic Evolution of the Northern Margin of North America |
topic_facet |
Tectonics Geology of North America strike-slip geochronology stratigraphy Alaska Yukon Ellesmere Island Geology Tectonics and Structure |
description |
The northern margin of North America records a protracted history of Neoproterozoic–early Paleozoic rifting and passive margin development, followed by the middle Paleozoic accretion of continental fragments. Contrasting tectonic models have been proposed for the history of continent separation, the role of strike-slip displacement during terrane accretion, and the Mesozoic opening of the Arctic Ocean. Here, I explore several of these models by investigating Neoproterozoic–early Paleozoic sedimentary and volcanic rocks across the northern margin of North American, as well as the main faulted boundaries between displaced terranes and autochthonous rocks of North America. First, I present a new tectonic model for late Ediacaran to early Cambrian rifting recorded in volcanic and sedimentary rocks of the Yelverton Formation exposed on northern Ellesmere Island, Canada. I constrain the timing of volcanism to ~570-530 Ma and relate it to decompression melting during progressive rifting. I suggest that rifting led to the separation of the North Slope subterrane of Arctic Alaska from the Laurentian margin. Second, I reconstruct the complex stratigraphy within the Porcupine Fault System, which marks the current tectonic boundary between the North Slope subterrane and the autochthonous Yukon block. I define a new succession of late Tonian sedimentary deposits, named the Ch’oodeenjìk succession. I suggest it represents a unique peri-Laurentian crustal fragment displaced along the Porcupine Fault System. Finally, I integrate detailed geological mapping with various thermochronometric and geochronometric techniques to determine the displacement history within the Porcupine Fault System. A new ca. 119 Ma U/Pb date on a calcite vein within the fault system highlights an episode of Early Cretaceous deformation, supporting models that involve terrane translation rather than rotation during the formation of the Canada Basin of the Arctic Ocean. Together, I propose that the northern margin of North America was characterized by ... |
format |
Text |
author |
Faehnrich, Karol |
author_facet |
Faehnrich, Karol |
author_sort |
Faehnrich, Karol |
title |
Tectonic Evolution of the Northern Margin of North America |
title_short |
Tectonic Evolution of the Northern Margin of North America |
title_full |
Tectonic Evolution of the Northern Margin of North America |
title_fullStr |
Tectonic Evolution of the Northern Margin of North America |
title_full_unstemmed |
Tectonic Evolution of the Northern Margin of North America |
title_sort |
tectonic evolution of the northern margin of north america |
publisher |
Dartmouth Digital Commons |
publishDate |
2023 |
url |
https://digitalcommons.dartmouth.edu/dissertations/154 https://digitalcommons.dartmouth.edu/context/dissertations/article/1144/viewcontent/Faehnrich_PhD_Thesis.pdf |
geographic |
Arctic Arctic Ocean Yukon Ellesmere Island Canada |
geographic_facet |
Arctic Arctic Ocean Yukon Ellesmere Island Canada |
genre |
Arctic Arctic Ocean canada basin Ellesmere Island north slope Alaska Yukon |
genre_facet |
Arctic Arctic Ocean canada basin Ellesmere Island north slope Alaska Yukon |
op_source |
Dartmouth College Ph.D Dissertations |
op_relation |
https://digitalcommons.dartmouth.edu/dissertations/154 https://digitalcommons.dartmouth.edu/context/dissertations/article/1144/viewcontent/Faehnrich_PhD_Thesis.pdf |
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1778520760075157504 |