Setting the Holocene clock using varved lake sediments in Sweden
The aim of this thesis was to study annually laminated (varved) Holocene lake sediment in Sweden, their formation and their potential as chronological and palaeoecological archives. Five lakes with continuous Holocene varved lake sediment sequences in northern (Västerbotten) and west central Sweden...
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Format: | Doctoral or Postdoctoral Thesis |
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Quaternary Sciences, Department of Geology, Lund University
2003
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Online Access: | https://lup.lub.lu.se/record/466190 https://portal.research.lu.se/files/4598425/3159876.PDF |
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ftulundlup:oai:lup.lub.lu.se:1f68e59a-85c7-4b17-a79b-cee1a0ce41d3 2023-05-15T16:19:41+02:00 Setting the Holocene clock using varved lake sediments in Sweden Zillén, Lovisa 2003 application/pdf https://lup.lub.lu.se/record/466190 https://portal.research.lu.se/files/4598425/3159876.PDF eng eng Quaternary Sciences, Department of Geology, Lund University https://lup.lub.lu.se/record/466190 urn:isbn:91-86746-52-9 https://portal.research.lu.se/files/4598425/3159876.PDF scopus:1642457195 info:eu-repo/semantics/openAccess Lundqua thesis; (50) (2003) ISSN: 0281-3033 Geology climate change Physical geography tephrochronology palaeomagnetic secular variations radiocarbon time-scale Holocene varved lake sediments varve chronology geomorphology pedology cartography climatology Fysisk geografi geomorfologi marklära kartografi klimatologi thesis/doccomp info:eu-repo/semantics/doctoralThesis text 2003 ftulundlup 2023-02-01T23:27:32Z The aim of this thesis was to study annually laminated (varved) Holocene lake sediment in Sweden, their formation and their potential as chronological and palaeoecological archives. Five lakes with continuous Holocene varved lake sediment sequences in northern (Västerbotten) and west central Sweden (Värmland) were investigated. Three of these sequences were discovered during this study, which identified the climatic and environmental prerequisites for the formation of varves and, therefore, provides a tool for finding annually laminated sediments in the Swedish boreal environment. Varve chronologies, supported by other independent dating methods, i.e. radiocarbon dating, tephra isochrones and paleomagnetic secular variations were established for two sediment sequences in Värmland. These are the longest geological records with an annual resolution known to exist in Sweden. Three mid-Holocene Icelandic tephra horizons were identified within 1-cm horizons, corresponding to c. 20 years of sediment accumulation and the varve chronologies were used to assign calendar years ages to the tephra isochrones with a precision better than ± 110 varve years. Paleomagnetic secular variation curves (both directions and intensity) presented in this thesis can be used to correlate and relatively date Holocene sedimentary sequences in Northwest and Central Europe. The accuracy and precision of the method is determined by errors associated with the varve chronologies (i.e. c. 1-2%), sampling resolution (c. 50-100 years), definition uncertainties and possible remanence lock-in effects. Comparison between the paleomagnetic secular variation curves in this study and previous obtained records from Northwest Europe suggests that no significant westwards drift of the non-dipole field has occurred in this region during the majority of the Holocene. Reconstructed virtual geomagnetic pole positions for the last c. 9000 show that the Magnetic North Pole has changed its position significantly during the Holocene. Relative palaeointensities ... Doctoral or Postdoctoral Thesis Geomagnetic Pole North Pole Lund University Publications (LUP) North Pole |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Geology climate change Physical geography tephrochronology palaeomagnetic secular variations radiocarbon time-scale Holocene varved lake sediments varve chronology geomorphology pedology cartography climatology Fysisk geografi geomorfologi marklära kartografi klimatologi |
spellingShingle |
Geology climate change Physical geography tephrochronology palaeomagnetic secular variations radiocarbon time-scale Holocene varved lake sediments varve chronology geomorphology pedology cartography climatology Fysisk geografi geomorfologi marklära kartografi klimatologi Zillén, Lovisa Setting the Holocene clock using varved lake sediments in Sweden |
topic_facet |
Geology climate change Physical geography tephrochronology palaeomagnetic secular variations radiocarbon time-scale Holocene varved lake sediments varve chronology geomorphology pedology cartography climatology Fysisk geografi geomorfologi marklära kartografi klimatologi |
description |
The aim of this thesis was to study annually laminated (varved) Holocene lake sediment in Sweden, their formation and their potential as chronological and palaeoecological archives. Five lakes with continuous Holocene varved lake sediment sequences in northern (Västerbotten) and west central Sweden (Värmland) were investigated. Three of these sequences were discovered during this study, which identified the climatic and environmental prerequisites for the formation of varves and, therefore, provides a tool for finding annually laminated sediments in the Swedish boreal environment. Varve chronologies, supported by other independent dating methods, i.e. radiocarbon dating, tephra isochrones and paleomagnetic secular variations were established for two sediment sequences in Värmland. These are the longest geological records with an annual resolution known to exist in Sweden. Three mid-Holocene Icelandic tephra horizons were identified within 1-cm horizons, corresponding to c. 20 years of sediment accumulation and the varve chronologies were used to assign calendar years ages to the tephra isochrones with a precision better than ± 110 varve years. Paleomagnetic secular variation curves (both directions and intensity) presented in this thesis can be used to correlate and relatively date Holocene sedimentary sequences in Northwest and Central Europe. The accuracy and precision of the method is determined by errors associated with the varve chronologies (i.e. c. 1-2%), sampling resolution (c. 50-100 years), definition uncertainties and possible remanence lock-in effects. Comparison between the paleomagnetic secular variation curves in this study and previous obtained records from Northwest Europe suggests that no significant westwards drift of the non-dipole field has occurred in this region during the majority of the Holocene. Reconstructed virtual geomagnetic pole positions for the last c. 9000 show that the Magnetic North Pole has changed its position significantly during the Holocene. Relative palaeointensities ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Zillén, Lovisa |
author_facet |
Zillén, Lovisa |
author_sort |
Zillén, Lovisa |
title |
Setting the Holocene clock using varved lake sediments in Sweden |
title_short |
Setting the Holocene clock using varved lake sediments in Sweden |
title_full |
Setting the Holocene clock using varved lake sediments in Sweden |
title_fullStr |
Setting the Holocene clock using varved lake sediments in Sweden |
title_full_unstemmed |
Setting the Holocene clock using varved lake sediments in Sweden |
title_sort |
setting the holocene clock using varved lake sediments in sweden |
publisher |
Quaternary Sciences, Department of Geology, Lund University |
publishDate |
2003 |
url |
https://lup.lub.lu.se/record/466190 https://portal.research.lu.se/files/4598425/3159876.PDF |
geographic |
North Pole |
geographic_facet |
North Pole |
genre |
Geomagnetic Pole North Pole |
genre_facet |
Geomagnetic Pole North Pole |
op_source |
Lundqua thesis; (50) (2003) ISSN: 0281-3033 |
op_relation |
https://lup.lub.lu.se/record/466190 urn:isbn:91-86746-52-9 https://portal.research.lu.se/files/4598425/3159876.PDF scopus:1642457195 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766006090136289280 |