Deglaciation history of Frøyabanken and Halsafjorden, Norway
Master thesis
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Date
2023-02-06Metadata
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- Master theses [113]
Abstract
This thesis aims to reconstruct post-glacial ice sheet dynamics on the Norwegian coast and adjacent continental shelf area, a region for which there is significant uncertainty regarding ice sheet movement due to a lack of reliable and accurate chronological data. To address this gap, new data from Halsafjorden Frøyabanken and previously published dates were analyzed using various geological and geophysical methods, including analyzing a 4.27 m gravity core from Frøyabanken. They were compared with geological and geophysical data provided by Fugro in Halsafjorden. The chronology of the events was compared with previously published data to retrace the ice sheet movement from Frøyabanken to Halsafjorden. All data were recalibrated using the Normarine18 curve to correct for potential dating errors. Based on the combined analysis of seismic stratigraphy, lithostratigraphy, and chronology, it is concluded that the deglaciation of Frøyabanken began around 17.7-17.1 ka cal. yrs BP was followed by a readvance, the Frøyabanken readvance, approximately 15.1 ka cal. yrs BP. The Halsafjorden region is believed to have become ice-free around 16-18 ka cal. yrs BP, with the overall retreat of the regional ice sheet across the mid-Norwegian continental shelf beginning around 18 ka cal. yrs BP. This retreat was followed by a Late Karmøy/Bremanger readvance of around 16-15 ka cal. yrs BP, possibly correlated with the Heinrich Event 1. The ice sheet then retreated from the shelf at around 15-14 ka cal. yrs BP, with the following possible local readvance occurring in the Haltenbanken region. The findings of this master thesis provide essential insights into the ice sheet dynamics of the Norwegian coast and continental shelf area following the last glacial maximum. These findings significantly impact our understanding of the glacial history of this region and have potential impacts on future research in this field.