Stratigraphy, palynology, and provenance of the Colorado Creek basin, Alaska, USA: Oligocene transpressional tectonics along the central Denali fault system
New sedimentologic, biostratigraphic, and compositional data from a 415-m-thick section of siliciclastic and volcanic strata document Oligocene synthrusting sedimentation south of the McKinley segment of the Denali fault system. Strata of the Colorado Creek basin are presently exposed on the south s...
Published in: | Canadian Journal of Earth Sciences |
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crcansciencepubl:10.1139/e04-003 2023-12-17T10:17:51+01:00 Stratigraphy, palynology, and provenance of the Colorado Creek basin, Alaska, USA: Oligocene transpressional tectonics along the central Denali fault system Trop, Jeffrey M Ridgway, Kenneth D Sweet, Arthur R 2004 http://dx.doi.org/10.1139/e04-003 http://www.nrcresearchpress.com/doi/pdf/10.1139/e04-003 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 41, issue 4, page 457-480 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 2004 crcansciencepubl https://doi.org/10.1139/e04-003 2023-11-19T13:38:36Z New sedimentologic, biostratigraphic, and compositional data from a 415-m-thick section of siliciclastic and volcanic strata document Oligocene synthrusting sedimentation south of the McKinley segment of the Denali fault system. Strata of the Colorado Creek basin are presently exposed on the south side of the central Alaska Range in the footwalls of north-dipping thrust faults. New measured sections define a three-part stratigraphy. Lowermost strata consist of a ~30-m-thick unit of marine sandstone and mudstone that contain Late Cretaceous dinoflagellate taxa. The middle unit consists of ~330 m of conglomerate, sandstone, and mudstone interpreted as braided stream and floodplain deposits. This middle unit contains early Oligocene pollen and spore assemblages. The upper unit is 55 m thick and contains lava flows, tuff, and pumice interpreted as the product of subaerial volcanic eruptions. Direct age data are lacking from the upper unit. Compositional data from the middle unit indicate that detritus was derived from sedimentary and igneous source terranes exposed on both the north and south side of the McKinley fault. Matching source lithologies north of the McKinley fault with conglomerate clast types in the Colorado Creek basin implies 3033 km of maximum post-early Oligocene dextral displacement along the fault. We interpret the Oligocene strata of the Colorado Creek basin as a product of transpressional deformation that produced north-dipping thrust faults associated with strike-slip displacement on the central Denali fault. Our data from the Colorado Creek basin, in combination with previous studies, document a major episode of middle Eocene late Oligocene synorogenic sedimentation along the Denali fault from British Columbia to southwestern Alaska. Article in Journal/Newspaper alaska range Alaska Canadian Science Publishing (via Crossref) Colorado Creek ENVELOPE(-138.850,-138.850,62.522,62.522) Canadian Journal of Earth Sciences 41 4 457 480 |
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 Trop, Jeffrey M Ridgway, Kenneth D Sweet, Arthur R Stratigraphy, palynology, and provenance of the Colorado Creek basin, Alaska, USA: Oligocene transpressional tectonics along the central Denali fault system |
topic_facet |
General Earth and Planetary Sciences |
description |
New sedimentologic, biostratigraphic, and compositional data from a 415-m-thick section of siliciclastic and volcanic strata document Oligocene synthrusting sedimentation south of the McKinley segment of the Denali fault system. Strata of the Colorado Creek basin are presently exposed on the south side of the central Alaska Range in the footwalls of north-dipping thrust faults. New measured sections define a three-part stratigraphy. Lowermost strata consist of a ~30-m-thick unit of marine sandstone and mudstone that contain Late Cretaceous dinoflagellate taxa. The middle unit consists of ~330 m of conglomerate, sandstone, and mudstone interpreted as braided stream and floodplain deposits. This middle unit contains early Oligocene pollen and spore assemblages. The upper unit is 55 m thick and contains lava flows, tuff, and pumice interpreted as the product of subaerial volcanic eruptions. Direct age data are lacking from the upper unit. Compositional data from the middle unit indicate that detritus was derived from sedimentary and igneous source terranes exposed on both the north and south side of the McKinley fault. Matching source lithologies north of the McKinley fault with conglomerate clast types in the Colorado Creek basin implies 3033 km of maximum post-early Oligocene dextral displacement along the fault. We interpret the Oligocene strata of the Colorado Creek basin as a product of transpressional deformation that produced north-dipping thrust faults associated with strike-slip displacement on the central Denali fault. Our data from the Colorado Creek basin, in combination with previous studies, document a major episode of middle Eocene late Oligocene synorogenic sedimentation along the Denali fault from British Columbia to southwestern Alaska. |
format |
Article in Journal/Newspaper |
author |
Trop, Jeffrey M Ridgway, Kenneth D Sweet, Arthur R |
author_facet |
Trop, Jeffrey M Ridgway, Kenneth D Sweet, Arthur R |
author_sort |
Trop, Jeffrey M |
title |
Stratigraphy, palynology, and provenance of the Colorado Creek basin, Alaska, USA: Oligocene transpressional tectonics along the central Denali fault system |
title_short |
Stratigraphy, palynology, and provenance of the Colorado Creek basin, Alaska, USA: Oligocene transpressional tectonics along the central Denali fault system |
title_full |
Stratigraphy, palynology, and provenance of the Colorado Creek basin, Alaska, USA: Oligocene transpressional tectonics along the central Denali fault system |
title_fullStr |
Stratigraphy, palynology, and provenance of the Colorado Creek basin, Alaska, USA: Oligocene transpressional tectonics along the central Denali fault system |
title_full_unstemmed |
Stratigraphy, palynology, and provenance of the Colorado Creek basin, Alaska, USA: Oligocene transpressional tectonics along the central Denali fault system |
title_sort |
stratigraphy, palynology, and provenance of the colorado creek basin, alaska, usa: oligocene transpressional tectonics along the central denali fault system |
publisher |
Canadian Science Publishing |
publishDate |
2004 |
url |
http://dx.doi.org/10.1139/e04-003 http://www.nrcresearchpress.com/doi/pdf/10.1139/e04-003 |
long_lat |
ENVELOPE(-138.850,-138.850,62.522,62.522) |
geographic |
Colorado Creek |
geographic_facet |
Colorado Creek |
genre |
alaska range Alaska |
genre_facet |
alaska range Alaska |
op_source |
Canadian Journal of Earth Sciences volume 41, issue 4, page 457-480 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e04-003 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
41 |
container_issue |
4 |
container_start_page |
457 |
op_container_end_page |
480 |
_version_ |
1785523475789643776 |