Ordovician to Devonian sea-level changes in western and northern Canada
Lower Paleozoic sediments of central, Cordilleran, and arctic Canada are dominated by two megafacies: supratidal to shallow subtidal carbonates and minor evaporites of the platformal (cratonic) areas, and deeper water dark shales and dark limestones of the slope and basinal areas. Large areas of the...
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crcansciencepubl:10.1139/e82-170 2023-12-17T10:25:45+01:00 Ordovician to Devonian sea-level changes in western and northern Canada Lenz, A. C. 1982 http://dx.doi.org/10.1139/e82-170 http://www.nrcresearchpress.com/doi/pdf/10.1139/e82-170 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 19, issue 10, page 1919-1932 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1982 crcansciencepubl https://doi.org/10.1139/e82-170 2023-11-19T13:38:54Z Lower Paleozoic sediments of central, Cordilleran, and arctic Canada are dominated by two megafacies: supratidal to shallow subtidal carbonates and minor evaporites of the platformal (cratonic) areas, and deeper water dark shales and dark limestones of the slope and basinal areas. Large areas of the platform may be covered or exposed in response to relatively small changes in sea level, whereas sea-level changes in the slope and basinal areas are generally recognized only in changes in the sediments and organism content.Employing multiple lines of evidence from stratigraphic, sedimentologic, and paleontologic data, it is generally possible to recognize bathymetrie changes in local stratigraphic sequences, although present inadequate knowledge of fossil "communities" prevents incorporation of that form of paleobathymetric analysis.Composite sections of platformal areas of the central Mackenzie Valley and Williston Basin and of deformed areas of Cornwallis–Bathurst Islands, northern Yukon, central Mackenzie Mountains, and northeastern British Columbia, as well as central and southern Nevada were examined for indications of sea-level changes. Assuming reasonable correlations between sections of the seven areas, fairly good evidence exists for widespread sea-level changes. Sea-level rises (transgressions) are suggested for the Tremadoc and Arenig, early Caradoc and Ashgill, late early and later Llandovery and earliest Wenlock, latest Wenlock and Ludlow, to some extent the Zlichov and Daleje (Emsian), late Eifel and early Givet, and especially Frasne. Sea-level lowering (regression) is indicated possibly for about the middle Arenig, the Llandeilo, approximately the middle Llandovery, the middle Wenlock, the Pridoli, and the lower Lochkov, and approximately the middle Eifel. Anomalies, probably the result of local orogenic activities, are evident in lower Lochkov, Prag, and upper Givet strata of Nevada and the central Arctic Islands. Article in Journal/Newspaper Arctic Central Arctic Mackenzie mountains Mackenzie Valley Yukon Canadian Science Publishing (via Crossref) Arctic Yukon Canada British Columbia ENVELOPE(-125.003,-125.003,54.000,54.000) Mackenzie Valley ENVELOPE(-126.070,-126.070,52.666,52.666) Cornwallis ENVELOPE(-54.464,-54.464,-61.072,-61.072) Canadian Journal of Earth Sciences 19 10 1919 1932 |
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 Lenz, A. C. Ordovician to Devonian sea-level changes in western and northern Canada |
topic_facet |
General Earth and Planetary Sciences |
description |
Lower Paleozoic sediments of central, Cordilleran, and arctic Canada are dominated by two megafacies: supratidal to shallow subtidal carbonates and minor evaporites of the platformal (cratonic) areas, and deeper water dark shales and dark limestones of the slope and basinal areas. Large areas of the platform may be covered or exposed in response to relatively small changes in sea level, whereas sea-level changes in the slope and basinal areas are generally recognized only in changes in the sediments and organism content.Employing multiple lines of evidence from stratigraphic, sedimentologic, and paleontologic data, it is generally possible to recognize bathymetrie changes in local stratigraphic sequences, although present inadequate knowledge of fossil "communities" prevents incorporation of that form of paleobathymetric analysis.Composite sections of platformal areas of the central Mackenzie Valley and Williston Basin and of deformed areas of Cornwallis–Bathurst Islands, northern Yukon, central Mackenzie Mountains, and northeastern British Columbia, as well as central and southern Nevada were examined for indications of sea-level changes. Assuming reasonable correlations between sections of the seven areas, fairly good evidence exists for widespread sea-level changes. Sea-level rises (transgressions) are suggested for the Tremadoc and Arenig, early Caradoc and Ashgill, late early and later Llandovery and earliest Wenlock, latest Wenlock and Ludlow, to some extent the Zlichov and Daleje (Emsian), late Eifel and early Givet, and especially Frasne. Sea-level lowering (regression) is indicated possibly for about the middle Arenig, the Llandeilo, approximately the middle Llandovery, the middle Wenlock, the Pridoli, and the lower Lochkov, and approximately the middle Eifel. Anomalies, probably the result of local orogenic activities, are evident in lower Lochkov, Prag, and upper Givet strata of Nevada and the central Arctic Islands. |
format |
Article in Journal/Newspaper |
author |
Lenz, A. C. |
author_facet |
Lenz, A. C. |
author_sort |
Lenz, A. C. |
title |
Ordovician to Devonian sea-level changes in western and northern Canada |
title_short |
Ordovician to Devonian sea-level changes in western and northern Canada |
title_full |
Ordovician to Devonian sea-level changes in western and northern Canada |
title_fullStr |
Ordovician to Devonian sea-level changes in western and northern Canada |
title_full_unstemmed |
Ordovician to Devonian sea-level changes in western and northern Canada |
title_sort |
ordovician to devonian sea-level changes in western and northern canada |
publisher |
Canadian Science Publishing |
publishDate |
1982 |
url |
http://dx.doi.org/10.1139/e82-170 http://www.nrcresearchpress.com/doi/pdf/10.1139/e82-170 |
long_lat |
ENVELOPE(-125.003,-125.003,54.000,54.000) ENVELOPE(-126.070,-126.070,52.666,52.666) ENVELOPE(-54.464,-54.464,-61.072,-61.072) |
geographic |
Arctic Yukon Canada British Columbia Mackenzie Valley Cornwallis |
geographic_facet |
Arctic Yukon Canada British Columbia Mackenzie Valley Cornwallis |
genre |
Arctic Central Arctic Mackenzie mountains Mackenzie Valley Yukon |
genre_facet |
Arctic Central Arctic Mackenzie mountains Mackenzie Valley Yukon |
op_source |
Canadian Journal of Earth Sciences volume 19, issue 10, page 1919-1932 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e82-170 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
19 |
container_issue |
10 |
container_start_page |
1919 |
op_container_end_page |
1932 |
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1785577409955758080 |