Siberian-Arctic shelf surface-sediments: sources, transport pathways and processes, and diagenetic alteration
This thesis investigates lithogenic sediments on the Siberian Arctic shelf, their sources, modes of dispersal, transport pathways and post-depositional diagenetic alteration. Working with cores collected from the Chukchi, East Siberian and Laptev Seas, we characterize surface-sediment elemental chem...
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Format: | Doctoral or Postdoctoral Thesis |
Language: | English unknown |
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Oregon State University
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Online Access: | https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/k930c044g |
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ftoregonstate:ir.library.oregonstate.edu:k930c044g 2024-09-09T19:20:52+00:00 Siberian-Arctic shelf surface-sediments: sources, transport pathways and processes, and diagenetic alteration Viscosi-Shirley, Carolyn Pisias, Nicklas G. Dymond, Jack Keszler, Doug Baham, John Falkner, Kelly College of Oceanic and Atmospheric Sciences Oregon State University. Graduate School https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/k930c044g English [eng] eng unknown Oregon State University https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/k930c044g Copyright Not Evaluated Arctic Coast (Russia) Diagenesis -- Arctic Ocean Marine sediments -- Arctic Ocean Dissertation ftoregonstate 2024-07-22T18:06:06Z This thesis investigates lithogenic sediments on the Siberian Arctic shelf, their sources, modes of dispersal, transport pathways and post-depositional diagenetic alteration. Working with cores collected from the Chukchi, East Siberian and Laptev Seas, we characterize surface-sediment elemental chemistry and clay mineralogy. We identify five regions with endmember sedimentary compositions. Comparing these data with a variety of geological, physical oceanographic and other environmental observations, we conclude that endmember formation is controlled by a complex combination of sediment provenance and various physical processes. Average sediment transport pathways are inferred from gradients in geochemical endmember flux distributions. On the Chukchi shelf sediment movement is primarily offshore. In the alongshore direction, available data suggest that sediment dispersal is predominately to the east in both the Chukchi and Laptev Seas. These results corroborate the limited observations of shelf currents and suggest circulation is key in determining dominant sediment transport pathways. In the Laptev Sea, offshore sediment movement is limited compared to alongshore sediment movement. This sedimentation pattern may be controlled by currents, or by removal of sediment from the central Laptev shelf via ice rafting. A fraction of the material deposited on the shelf is recycled to overlying waters by sediment diagenesis. Chukchi surface sediments are typically depleted in Mn and Co relative to values predicted based on sediment source rock geology. Evaluating these metal depletions in the context of shelf primary production gradients and surface sediment color observations, we conclude they are caused by dissolved metal fluxes from suboxic surface sediments to overlying waters. We estimate that sediments within our Chukchi study area release 4.5-6.1 x 1O⁴ tons/yr of dissolved Mn. Less than 1/20th of this Mn is sequestered as reactive Mn in lower Chukchi slope and Canadian basin sediments. Reactive Mn deposition ... Doctoral or Postdoctoral Thesis Arctic Arctic Ocean Chukchi laptev Laptev Sea ScholarsArchive@OSU (Oregon State University) Arctic Arctic Ocean Chukchi Shelf ENVELOPE(-169.167,-169.167,70.550,70.550) Laptev Sea |
institution |
Open Polar |
collection |
ScholarsArchive@OSU (Oregon State University) |
op_collection_id |
ftoregonstate |
language |
English unknown |
topic |
Arctic Coast (Russia) Diagenesis -- Arctic Ocean Marine sediments -- Arctic Ocean |
spellingShingle |
Arctic Coast (Russia) Diagenesis -- Arctic Ocean Marine sediments -- Arctic Ocean Viscosi-Shirley, Carolyn Siberian-Arctic shelf surface-sediments: sources, transport pathways and processes, and diagenetic alteration |
topic_facet |
Arctic Coast (Russia) Diagenesis -- Arctic Ocean Marine sediments -- Arctic Ocean |
description |
This thesis investigates lithogenic sediments on the Siberian Arctic shelf, their sources, modes of dispersal, transport pathways and post-depositional diagenetic alteration. Working with cores collected from the Chukchi, East Siberian and Laptev Seas, we characterize surface-sediment elemental chemistry and clay mineralogy. We identify five regions with endmember sedimentary compositions. Comparing these data with a variety of geological, physical oceanographic and other environmental observations, we conclude that endmember formation is controlled by a complex combination of sediment provenance and various physical processes. Average sediment transport pathways are inferred from gradients in geochemical endmember flux distributions. On the Chukchi shelf sediment movement is primarily offshore. In the alongshore direction, available data suggest that sediment dispersal is predominately to the east in both the Chukchi and Laptev Seas. These results corroborate the limited observations of shelf currents and suggest circulation is key in determining dominant sediment transport pathways. In the Laptev Sea, offshore sediment movement is limited compared to alongshore sediment movement. This sedimentation pattern may be controlled by currents, or by removal of sediment from the central Laptev shelf via ice rafting. A fraction of the material deposited on the shelf is recycled to overlying waters by sediment diagenesis. Chukchi surface sediments are typically depleted in Mn and Co relative to values predicted based on sediment source rock geology. Evaluating these metal depletions in the context of shelf primary production gradients and surface sediment color observations, we conclude they are caused by dissolved metal fluxes from suboxic surface sediments to overlying waters. We estimate that sediments within our Chukchi study area release 4.5-6.1 x 1O⁴ tons/yr of dissolved Mn. Less than 1/20th of this Mn is sequestered as reactive Mn in lower Chukchi slope and Canadian basin sediments. Reactive Mn deposition ... |
author2 |
Pisias, Nicklas G. Dymond, Jack Keszler, Doug Baham, John Falkner, Kelly College of Oceanic and Atmospheric Sciences Oregon State University. Graduate School |
format |
Doctoral or Postdoctoral Thesis |
author |
Viscosi-Shirley, Carolyn |
author_facet |
Viscosi-Shirley, Carolyn |
author_sort |
Viscosi-Shirley, Carolyn |
title |
Siberian-Arctic shelf surface-sediments: sources, transport pathways and processes, and diagenetic alteration |
title_short |
Siberian-Arctic shelf surface-sediments: sources, transport pathways and processes, and diagenetic alteration |
title_full |
Siberian-Arctic shelf surface-sediments: sources, transport pathways and processes, and diagenetic alteration |
title_fullStr |
Siberian-Arctic shelf surface-sediments: sources, transport pathways and processes, and diagenetic alteration |
title_full_unstemmed |
Siberian-Arctic shelf surface-sediments: sources, transport pathways and processes, and diagenetic alteration |
title_sort |
siberian-arctic shelf surface-sediments: sources, transport pathways and processes, and diagenetic alteration |
publisher |
Oregon State University |
url |
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/k930c044g |
long_lat |
ENVELOPE(-169.167,-169.167,70.550,70.550) |
geographic |
Arctic Arctic Ocean Chukchi Shelf Laptev Sea |
geographic_facet |
Arctic Arctic Ocean Chukchi Shelf Laptev Sea |
genre |
Arctic Arctic Ocean Chukchi laptev Laptev Sea |
genre_facet |
Arctic Arctic Ocean Chukchi laptev Laptev Sea |
op_relation |
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/k930c044g |
op_rights |
Copyright Not Evaluated |
_version_ |
1809761068356993024 |