A multimethod approach to dating Quaternary sediments from the Arctic Ocean
The marine sedimentary environment in the polar regions is different from the rest of the world’s oceans, as it is greatly influenced by the cryosphere. In the Arctic, sea ice and icebergs can transport vast amounts of sediments, delivered by extensive fluvial systems from the surrounding continents...
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Stockholms universitet, Institutionen för geologiska vetenskaper
2022
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ftstockholmuniv:oai:DiVA.org:su-199265 2023-05-15T14:37:39+02:00 A multimethod approach to dating Quaternary sediments from the Arctic Ocean West, Gabriel 2022 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-199265 eng eng Stockholms universitet, Institutionen för geologiska vetenskaper Stockholm : Department of Geological Sciences, Stockholm University Meddelanden från Stockholms universitets institution för geologiska vetenskaper 383 orcid:0000-0002-6458-6245 http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-199265 urn:isbn:978-91-7911-724-5 urn:isbn:978-91-7911-725-2 info:eu-repo/semantics/openAccess Arctic Ocean Amino Acid Geochronology Optically Stimulated Luminescence Dating Palaeomagnetism Geology Geologi Earth and Related Environmental Sciences Geovetenskap och miljövetenskap Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2022 ftstockholmuniv 2023-02-23T21:41:04Z The marine sedimentary environment in the polar regions is different from the rest of the world’s oceans, as it is greatly influenced by the cryosphere. In the Arctic, sea ice and icebergs can transport vast amounts of sediments, delivered by extensive fluvial systems from the surrounding continents, which have been shaped by the waxing and waning of large terrestrial ice sheets during the Quaternary period. Reconstructing palaeoenvironmental changes in the Arctic Ocean during this time requires the accurate dating of marine sediment cores, something that has been more difficult than in most other marine environments. This thesis investigates and integrates less developed methods to date marine sediments in the Arctic Ocean. It focuses on applying amino acid racemization geochronology and optically stimulated luminescence dating to sediments from across the Arctic Ocean, accompanied by palaeo- and rock magnetic measurements, and sedimentological analyses. The presented results show that racemization of aspartic and glutamic acids in foraminifera follow a predictable rate at the Yermak Plateau and the Greenland and Iceland Seas, and existing calibrated age equations can be used to confidently date late Quaternary sediments in these regions. Purportedly high rates of racemization are observed in the benthic foraminifera, Cibicidoides wuellerstorfi from central Arctic sediments, confirming that the high rates cannot be attributed to taxonomic effects. Their possible causes, which include variable environmental and diagenetic conditions are considered. Optically stimulated luminescence dating of quartz grains from the Lomonosov Ridge provide much needed absolute age control for sediments from this area, further constraining the timing of glacial activity near the Siberian margin and illustrating the potentials of luminescence dating as a geochronological tool in the Arctic. Palaeomagnetic and rock magnetic analyses provide additional evidence that putative polarity reversals and excursions are not always due to ... Doctoral or Postdoctoral Thesis Arctic Arctic Ocean Foraminifera* Greenland Iceberg* Iceland Lomonosov Ridge Sea ice Yermak plateau Stockholm University: Publications (DiVA) Arctic Arctic Ocean Greenland Yermak Plateau ENVELOPE(5.000,5.000,81.250,81.250) |
institution |
Open Polar |
collection |
Stockholm University: Publications (DiVA) |
op_collection_id |
ftstockholmuniv |
language |
English |
topic |
Arctic Ocean Amino Acid Geochronology Optically Stimulated Luminescence Dating Palaeomagnetism Geology Geologi Earth and Related Environmental Sciences Geovetenskap och miljövetenskap |
spellingShingle |
Arctic Ocean Amino Acid Geochronology Optically Stimulated Luminescence Dating Palaeomagnetism Geology Geologi Earth and Related Environmental Sciences Geovetenskap och miljövetenskap West, Gabriel A multimethod approach to dating Quaternary sediments from the Arctic Ocean |
topic_facet |
Arctic Ocean Amino Acid Geochronology Optically Stimulated Luminescence Dating Palaeomagnetism Geology Geologi Earth and Related Environmental Sciences Geovetenskap och miljövetenskap |
description |
The marine sedimentary environment in the polar regions is different from the rest of the world’s oceans, as it is greatly influenced by the cryosphere. In the Arctic, sea ice and icebergs can transport vast amounts of sediments, delivered by extensive fluvial systems from the surrounding continents, which have been shaped by the waxing and waning of large terrestrial ice sheets during the Quaternary period. Reconstructing palaeoenvironmental changes in the Arctic Ocean during this time requires the accurate dating of marine sediment cores, something that has been more difficult than in most other marine environments. This thesis investigates and integrates less developed methods to date marine sediments in the Arctic Ocean. It focuses on applying amino acid racemization geochronology and optically stimulated luminescence dating to sediments from across the Arctic Ocean, accompanied by palaeo- and rock magnetic measurements, and sedimentological analyses. The presented results show that racemization of aspartic and glutamic acids in foraminifera follow a predictable rate at the Yermak Plateau and the Greenland and Iceland Seas, and existing calibrated age equations can be used to confidently date late Quaternary sediments in these regions. Purportedly high rates of racemization are observed in the benthic foraminifera, Cibicidoides wuellerstorfi from central Arctic sediments, confirming that the high rates cannot be attributed to taxonomic effects. Their possible causes, which include variable environmental and diagenetic conditions are considered. Optically stimulated luminescence dating of quartz grains from the Lomonosov Ridge provide much needed absolute age control for sediments from this area, further constraining the timing of glacial activity near the Siberian margin and illustrating the potentials of luminescence dating as a geochronological tool in the Arctic. Palaeomagnetic and rock magnetic analyses provide additional evidence that putative polarity reversals and excursions are not always due to ... |
format |
Doctoral or Postdoctoral Thesis |
author |
West, Gabriel |
author_facet |
West, Gabriel |
author_sort |
West, Gabriel |
title |
A multimethod approach to dating Quaternary sediments from the Arctic Ocean |
title_short |
A multimethod approach to dating Quaternary sediments from the Arctic Ocean |
title_full |
A multimethod approach to dating Quaternary sediments from the Arctic Ocean |
title_fullStr |
A multimethod approach to dating Quaternary sediments from the Arctic Ocean |
title_full_unstemmed |
A multimethod approach to dating Quaternary sediments from the Arctic Ocean |
title_sort |
multimethod approach to dating quaternary sediments from the arctic ocean |
publisher |
Stockholms universitet, Institutionen för geologiska vetenskaper |
publishDate |
2022 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-199265 |
long_lat |
ENVELOPE(5.000,5.000,81.250,81.250) |
geographic |
Arctic Arctic Ocean Greenland Yermak Plateau |
geographic_facet |
Arctic Arctic Ocean Greenland Yermak Plateau |
genre |
Arctic Arctic Ocean Foraminifera* Greenland Iceberg* Iceland Lomonosov Ridge Sea ice Yermak plateau |
genre_facet |
Arctic Arctic Ocean Foraminifera* Greenland Iceberg* Iceland Lomonosov Ridge Sea ice Yermak plateau |
op_relation |
Meddelanden från Stockholms universitets institution för geologiska vetenskaper 383 orcid:0000-0002-6458-6245 http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-199265 urn:isbn:978-91-7911-724-5 urn:isbn:978-91-7911-725-2 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766309870656552960 |