Late Cenozoic unroofing sequence and foreland basin development of the central Alaska Range: implications from the Nenana Gravel
Thesis (M.S.) University of Alaska Fairbanks, 2000 Facies architecture analysis, lithostratigraphy, and ⁴⁰AR/³⁹AR analyses of syn-orogenic sediments from the Nenana Gravel consistently demonstrate that deformation and erosion of the Late Cenozoic Alaska Range progressed in a foreland propagating seq...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/6714 2023-05-15T13:09:36+02:00 Late Cenozoic unroofing sequence and foreland basin development of the central Alaska Range: implications from the Nenana Gravel Thoms, E. E. 2000-05 http://hdl.handle.net/11122/6714 en_US eng http://hdl.handle.net/11122/6714 Thesis 2000 ftunivalaska 2023-02-23T21:36:42Z Thesis (M.S.) University of Alaska Fairbanks, 2000 Facies architecture analysis, lithostratigraphy, and ⁴⁰AR/³⁹AR analyses of syn-orogenic sediments from the Nenana Gravel consistently demonstrate that deformation and erosion of the Late Cenozoic Alaska Range progressed in a foreland propagating sequence. Alluvial braidplain sediments, the oldest sourced from south of the present range divide, were shed into depozones exhibiting characteristics that indicate the growth of an underlying orogenic wedge primarily controlled deposition. Those characteristics include very immature and locally derived sediments, erosional unconformities, evidence for the competing influences of uplift and subsidence, lithology transitions that are correlated with facies transitions, and evidence for drainages that were defeated by surface uplift. Deposition of the Nenana Gravel took place between roughly 7 and 3 Ma. The Nenana Gravel depositional system changed when deformation within the proximal reaches of the basin brought resistant basement rocks to the surface forcing antecedent drainages to incise and abandon the alluvial braidplain they once fed. Thesis alaska range Alaska University of Alaska: ScholarWorks@UA Fairbanks |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
description |
Thesis (M.S.) University of Alaska Fairbanks, 2000 Facies architecture analysis, lithostratigraphy, and ⁴⁰AR/³⁹AR analyses of syn-orogenic sediments from the Nenana Gravel consistently demonstrate that deformation and erosion of the Late Cenozoic Alaska Range progressed in a foreland propagating sequence. Alluvial braidplain sediments, the oldest sourced from south of the present range divide, were shed into depozones exhibiting characteristics that indicate the growth of an underlying orogenic wedge primarily controlled deposition. Those characteristics include very immature and locally derived sediments, erosional unconformities, evidence for the competing influences of uplift and subsidence, lithology transitions that are correlated with facies transitions, and evidence for drainages that were defeated by surface uplift. Deposition of the Nenana Gravel took place between roughly 7 and 3 Ma. The Nenana Gravel depositional system changed when deformation within the proximal reaches of the basin brought resistant basement rocks to the surface forcing antecedent drainages to incise and abandon the alluvial braidplain they once fed. |
format |
Thesis |
author |
Thoms, E. E. |
spellingShingle |
Thoms, E. E. Late Cenozoic unroofing sequence and foreland basin development of the central Alaska Range: implications from the Nenana Gravel |
author_facet |
Thoms, E. E. |
author_sort |
Thoms, E. E. |
title |
Late Cenozoic unroofing sequence and foreland basin development of the central Alaska Range: implications from the Nenana Gravel |
title_short |
Late Cenozoic unroofing sequence and foreland basin development of the central Alaska Range: implications from the Nenana Gravel |
title_full |
Late Cenozoic unroofing sequence and foreland basin development of the central Alaska Range: implications from the Nenana Gravel |
title_fullStr |
Late Cenozoic unroofing sequence and foreland basin development of the central Alaska Range: implications from the Nenana Gravel |
title_full_unstemmed |
Late Cenozoic unroofing sequence and foreland basin development of the central Alaska Range: implications from the Nenana Gravel |
title_sort |
late cenozoic unroofing sequence and foreland basin development of the central alaska range: implications from the nenana gravel |
publishDate |
2000 |
url |
http://hdl.handle.net/11122/6714 |
geographic |
Fairbanks |
geographic_facet |
Fairbanks |
genre |
alaska range Alaska |
genre_facet |
alaska range Alaska |
op_relation |
http://hdl.handle.net/11122/6714 |
_version_ |
1766189647222800384 |