Investigations of temporal changes in climate and the geomagnetic field via high-resolution radiocarbon dating
Author
Summary, in English
The 14C wiggle-match dating technique was successfully applied to construct an accurate and precise chronology of the annually laminated (varved) sediments of Lake Gyltigesjön in south-west Sweden for the period around 3000-2000 cal BP. With this technique, it was possible to estimate the old-carbon effect (14C reservoir age) in the lake sediments. The bulk sediment based chronology was validated by comparison to the 14C ages of plant macrofossils. Similarly, the 14C wiggle-match dating technique was used to test the accuracy of a varve chronology of Lake Kälksjön in west-central Sweden for the same time period. The constructed chronologies of Lake Gyltigesjön and Lake Kälksjön have uncertainties of only ±30 and ±20 years (95.4% probability range), respectively. The well-constrained chronologies enabled investigations of the post-depositional remanent magnetisation lock-in effect and its influence on records of palaeomagnetic secular variation.
In addition, the hypothesis of a solar-induced climate change in southern Sweden around 2800 cal BP was investigated. The peat record of Undarsmosse in south-west Sweden has previously indicated a change to increased storminess and wet¬ter conditions around this period. The 14C wiggle-match dating technique was applied to constrain the timing of these events. Within the age model uncertainties, the shift towards wetter and windier conditions in southern Sweden can be regarded synchronous with the climate changes inferred from other sites in Europe. The recorded changes, therefore, support the hypothesis of a shift in the larger-scale atmospheric circulation, possibly induced by decreased solar activity.
Publishing year
2014
Language
English
Publication/Series
Lundqua thesis
Issue
73
Full text
Document type
Dissertation
Publisher
Department of Geology, Lund University
Topic
- Geology
Keywords
- wiggle-matching
- Radiocarbon dating
- 14C
- 2800 cal BP
- climate change
- solar activity
- palaeomagnetism
- lake sediments
- varves
- post-depositional remanent magnetisation
- PDRM
- lock-in
- peat deposits
- Sweden
Status
Published
Supervisor
- Raimund Muscheler
- Ian Snowball
- Nathalie van Der Putten
- Svante Björck
- Göran Skog
ISBN/ISSN/Other
- ISSN: 0281-3033
- ISSN: 0281-3033
- ISBN: 978-91-86746-99-5
Defence date
13 June 2014
Defence time
13:15
Defence place
Geocentrum IIs föreläsningssal Pangea, Sölvegatan 12, 223 62 Lund
Opponent
- Bas van Geel (Dr.)