Post-IR IRSL dating of K-feldspar from Loess at Lowland Point, SW England : Developing a Chronology for Past Climate Records
Loess deposits are terrestrial clastic sediments derived from aeolian deposition. Loess is transported in periglacial conditions and was mainly deposited in cold environments around glaciers during the Quaternary period. To be able to understand and interpret past climate and how it was changing, lo...
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Uppsala universitet, Institutionen för geovetenskaper
2022
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ftuppsalauniv:oai:DiVA.org:uu-476903 2023-05-15T16:37:57+02:00 Post-IR IRSL dating of K-feldspar from Loess at Lowland Point, SW England : Developing a Chronology for Past Climate Records Post-IR IRSL datering av kalifältspat från löss vid Lowland Point, sydvästra England : utveckling av kronologi för tidigare klimatregister Törnqvist, Elin 2022 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-476903 eng eng Uppsala universitet, Institutionen för geovetenskaper http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-476903 info:eu-repo/semantics/openAccess loess post-IR IRSL Lowland Point SW England Quaternary löss England kvartär Physical Geography Naturgeografi Student thesis info:eu-repo/semantics/bachelorThesis text 2022 ftuppsalauniv 2023-02-23T21:59:24Z Loess deposits are terrestrial clastic sediments derived from aeolian deposition. Loess is transported in periglacial conditions and was mainly deposited in cold environments around glaciers during the Quaternary period. To be able to understand and interpret past climate and how it was changing, loess deposits can be used as an indicator for example wind circulation and dustiness in the atmosphere. However, good independent chronological control is essential for using loess as a past climate archive. This study has examined loess from Lowland Point in the southwest of England. The loess at Lowland Point is relatively thin at 180 cm compared with more studied loess deposits further east on continental Europe. To be able to date the k-feldspar mineral grains from the loess deposit at Lowland Point, two values should be constrained for each sample: the equivalent dose (DE), a quantitative factor of the amount of energy accumulated by the mineral grain during burial from ionising radiation, and the dose rate (DR), a rate of ionising radiation absorbed from the surrounding environment per year. By using the post infrared-infrared stimulated luminescence (post-IR IRSL) method, the DE values were obtained, and by examine radioactive isotopes in the samples, the DR values were attained. The results of each average age per sample depth was then identified and the loess deposit could be determined to the age about 10.8-22.4 ka, which is suggested to have been deposited by meltwater from the British Irish Ice Sheet and permafrost. Lössjordar är avlagringar av markbundna klastiska sediment härledda från eolisk deposition och transporteras under periglaciala förhållanden för att huvudsakligen deponeras i kalla miljöer runt glaciärer under kvartärperioden. För att kunna förstå och tolka tidigare klimat och hur det förändrades kan lössavlagringar användas som en indikation över till exempel vindcirkulation och dammighet i atmosfären. Denna studie har undersökt löss från Lowland Point i sydvästra England. Lössen vid Lowland ... Bachelor Thesis Ice Ice Sheet permafrost Uppsala University: Publications (DiVA) Kalla ENVELOPE(19.617,19.617,67.050,67.050) |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
loess post-IR IRSL Lowland Point SW England Quaternary löss England kvartär Physical Geography Naturgeografi |
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loess post-IR IRSL Lowland Point SW England Quaternary löss England kvartär Physical Geography Naturgeografi Törnqvist, Elin Post-IR IRSL dating of K-feldspar from Loess at Lowland Point, SW England : Developing a Chronology for Past Climate Records |
topic_facet |
loess post-IR IRSL Lowland Point SW England Quaternary löss England kvartär Physical Geography Naturgeografi |
description |
Loess deposits are terrestrial clastic sediments derived from aeolian deposition. Loess is transported in periglacial conditions and was mainly deposited in cold environments around glaciers during the Quaternary period. To be able to understand and interpret past climate and how it was changing, loess deposits can be used as an indicator for example wind circulation and dustiness in the atmosphere. However, good independent chronological control is essential for using loess as a past climate archive. This study has examined loess from Lowland Point in the southwest of England. The loess at Lowland Point is relatively thin at 180 cm compared with more studied loess deposits further east on continental Europe. To be able to date the k-feldspar mineral grains from the loess deposit at Lowland Point, two values should be constrained for each sample: the equivalent dose (DE), a quantitative factor of the amount of energy accumulated by the mineral grain during burial from ionising radiation, and the dose rate (DR), a rate of ionising radiation absorbed from the surrounding environment per year. By using the post infrared-infrared stimulated luminescence (post-IR IRSL) method, the DE values were obtained, and by examine radioactive isotopes in the samples, the DR values were attained. The results of each average age per sample depth was then identified and the loess deposit could be determined to the age about 10.8-22.4 ka, which is suggested to have been deposited by meltwater from the British Irish Ice Sheet and permafrost. Lössjordar är avlagringar av markbundna klastiska sediment härledda från eolisk deposition och transporteras under periglaciala förhållanden för att huvudsakligen deponeras i kalla miljöer runt glaciärer under kvartärperioden. För att kunna förstå och tolka tidigare klimat och hur det förändrades kan lössavlagringar användas som en indikation över till exempel vindcirkulation och dammighet i atmosfären. Denna studie har undersökt löss från Lowland Point i sydvästra England. Lössen vid Lowland ... |
format |
Bachelor Thesis |
author |
Törnqvist, Elin |
author_facet |
Törnqvist, Elin |
author_sort |
Törnqvist, Elin |
title |
Post-IR IRSL dating of K-feldspar from Loess at Lowland Point, SW England : Developing a Chronology for Past Climate Records |
title_short |
Post-IR IRSL dating of K-feldspar from Loess at Lowland Point, SW England : Developing a Chronology for Past Climate Records |
title_full |
Post-IR IRSL dating of K-feldspar from Loess at Lowland Point, SW England : Developing a Chronology for Past Climate Records |
title_fullStr |
Post-IR IRSL dating of K-feldspar from Loess at Lowland Point, SW England : Developing a Chronology for Past Climate Records |
title_full_unstemmed |
Post-IR IRSL dating of K-feldspar from Loess at Lowland Point, SW England : Developing a Chronology for Past Climate Records |
title_sort |
post-ir irsl dating of k-feldspar from loess at lowland point, sw england : developing a chronology for past climate records |
publisher |
Uppsala universitet, Institutionen för geovetenskaper |
publishDate |
2022 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-476903 |
long_lat |
ENVELOPE(19.617,19.617,67.050,67.050) |
geographic |
Kalla |
geographic_facet |
Kalla |
genre |
Ice Ice Sheet permafrost |
genre_facet |
Ice Ice Sheet permafrost |
op_relation |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-476903 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766028255654051840 |