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Deglaciation history and subsequent lake dynamics in the Siljan region, south-central Sweden, based on new LiDAR evidence and sediment records

Möller, Per LU orcid ; Björck, Svante LU ; Dowling, T.P.F. ; Hammarlund, Dan LU ; Jakobsson, Martin ; Ljung, Karl LU orcid ; Lund, Martin LU and Paradeisis-Stathis, Savvas (2022) In Earth Surface Processes and Landforms 47. p.3515-3545
Abstract
The Siljan region hosts Europe´s largest impact structure. The high-relief landscape, with a central granite dome bordered by lake basins, contains an array of glacial and shore-level landforms. We investigated its deglaciation history by mapping and analysing landforms on high resolution LiDAR-based Digital Surface Models coupled with well-dated sediment successions from peat and lake sediment cores. The granite dome and bordering areas are characterized by streamlined terrain and ribbed moraine with a streamlined overprint. These suggest an ice-flow direction from NNW with wet-based thermal conditions prior to deglaciation. During its retreat, the ice sheet was split into thinner plateau ice and thicker basin ice. Sets of low-gradient... (More)
The Siljan region hosts Europe´s largest impact structure. The high-relief landscape, with a central granite dome bordered by lake basins, contains an array of glacial and shore-level landforms. We investigated its deglaciation history by mapping and analysing landforms on high resolution LiDAR-based Digital Surface Models coupled with well-dated sediment successions from peat and lake sediment cores. The granite dome and bordering areas are characterized by streamlined terrain and ribbed moraine with a streamlined overprint. These suggest an ice-flow direction from NNW with wet-based thermal conditions prior to deglaciation. During its retreat, the ice sheet was split into thinner plateau ice and thicker basin ice. Sets of low-gradient glaciofluvial erosion channels suggest intense ice-lateral meltwater drainage across gradually ice-freed slopes, while 'down-the-slope' erosion channels and eskers show meltwater drainage from stagnated plateau ice. Thick basin ice receded with a subaqueous margin across the deep Siljan–Orsasjön Basin c. 10,700–10,500 cal. BP. During ice recession the ingression of the Baltic Ancylus Lake led to diachronous formation of highest shoreline marks, from c. 207 m in the south to c. 220 m a.s.l. in the north. Differential uplift resulted in shallowing of the water body, which led to the isolation of the Siljan–Orsasjön Basin from the Baltic Basin at c. 9800 cal. BP. The post-isolation water body – the ‘Ancient Lake Siljan' – was drained through the ancient Åkerö Channel with a water level at 168–169 m a.s.l. during c. 1000 years. A later rerouting of the outlet to the present course was initiated at c. 8800 cal. BP, which led to a lake-level lowering of 6–7 m to today’s level of Lake Siljan (c. 162 m a.s.l.). This study shows the strength of an integrated methodological approach for deciphering the evolution of a complex landscape, combining highly resolved geomorphological analysis with well-dated sediment successions. (Less)
Abstract (Swedish)
The Siljan region hosts Europe´s largest impact structure. The high-relief landscape, with a central granite dome bordered by lake basins, contains an array of glacial and shore-level landforms. We investigated its deglaciation history by mapping and analysing landforms on high resolution LiDAR-based Digital Surface Models coupled with well-dated sediment successions from peat and lake sediment cores. The granite dome and bordering areas are characterized by streamlined terrain and ribbed moraine with a streamlined overprint. These suggest an ice-flow direction from NNW with wet-based thermal conditions prior to deglaciation. During its retreat, the ice sheet was split into thinner plateau ice and thicker basin ice. Sets of low-gradient... (More)
The Siljan region hosts Europe´s largest impact structure. The high-relief landscape, with a central granite dome bordered by lake basins, contains an array of glacial and shore-level landforms. We investigated its deglaciation history by mapping and analysing landforms on high resolution LiDAR-based Digital Surface Models coupled with well-dated sediment successions from peat and lake sediment cores. The granite dome and bordering areas are characterized by streamlined terrain and ribbed moraine with a streamlined overprint. These suggest an ice-flow direction from NNW with wet-based thermal conditions prior to deglaciation. During its retreat, the ice sheet was split into thinner plateau ice and thicker basin ice. Sets of low-gradient glaciofluvial erosion channels suggest intense ice-lateral meltwater drainage across gradually ice-freed slopes, while 'down-the-slope' erosion channels and eskers show meltwater drainage from stagnated plateau ice. Thick basin ice receded with a subaqueous margin across the deep Siljan–Orsasjön Basin c. 10,700–10,500 cal. BP. During ice recession the ingression of the Baltic Ancylus Lake led to diachronous formation of highest shoreline marks, from 207 m in the south to 220 m a.s.l. in the north. Differential uplift resulted in shallowing of the water body, which led to the isolation of the Siljan¬–Orsasjön Basin from the Baltic Basin at c. 9800 cal. BP. The post-isolation water body – the ‘Ancient Lake Siljan' – was drained through the ancient Åkerö Channel with a water level at 168–169 m a.s.l. during c. 1000 years. A later rerouting of the outlet to the present course was initiated at c. 8800 cal. BP, which led to a lake-level lowering of 6–7 m to today’s level of Lake Siljan (162 m a.s.l.). This study shows the strength of an integrated methodological approach for deciphering the evolution of a complex landscape, combining highly resolved geomorphological analysis with well-dated sediment successions. (Less)
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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Dalarna, ice sheet recession, glacial geomorphology, streamlined terrain, ribbed moraine, glaciofluvial deposits, lake isolation, drainage re-routing, lake bathymetry, ice-dammed lake, shoreline displacement, Baltic Basin, glacio-isostatic rebound, LiDAR, digital terrain models
in
Earth Surface Processes and Landforms
volume
47
pages
3515 - 3545
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:85138985081
ISSN
0197-9337
DOI
10.1002/esp.5471
language
English
LU publication?
yes
id
d90f220b-6d6b-47dd-877a-f64a05762cc8
date added to LUP
2022-08-22 11:37:34
date last changed
2023-05-16 12:57:28
@article{d90f220b-6d6b-47dd-877a-f64a05762cc8,
  abstract     = {{The Siljan region hosts Europe´s largest impact structure. The high-relief landscape, with a central granite dome bordered by lake basins, contains an array of glacial and shore-level landforms. We investigated its deglaciation history by mapping and analysing landforms on high resolution LiDAR-based Digital Surface Models coupled with well-dated sediment successions from peat and lake sediment cores. The granite dome and bordering areas are characterized by streamlined terrain and ribbed moraine with a streamlined overprint. These suggest an ice-flow direction from NNW with wet-based thermal conditions prior to deglaciation. During its retreat, the ice sheet was split into thinner plateau ice and thicker basin ice. Sets of low-gradient glaciofluvial erosion channels suggest intense ice-lateral meltwater drainage across gradually ice-freed slopes, while 'down-the-slope' erosion channels and eskers show meltwater drainage from stagnated plateau ice. Thick basin ice receded with a subaqueous margin across the deep Siljan–Orsasjön Basin c. 10,700–10,500 cal. BP. During ice recession the ingression of the Baltic Ancylus Lake led to diachronous formation of highest shoreline marks, from c. 207 m in the south to c. 220 m a.s.l. in the north. Differential uplift resulted in shallowing of the water body, which led to the isolation of the Siljan–Orsasjön Basin from the Baltic Basin at c. 9800 cal. BP. The post-isolation water body – the ‘Ancient Lake Siljan' – was drained through the ancient Åkerö Channel with a water level at 168–169 m a.s.l. during c. 1000 years. A later rerouting of the outlet to the present course was initiated at c. 8800 cal. BP, which led to a lake-level lowering of 6–7 m to today’s level of Lake Siljan (c. 162 m a.s.l.). This study shows the strength of an integrated methodological approach for deciphering the evolution of a complex landscape, combining highly resolved geomorphological analysis with well-dated sediment successions.}},
  author       = {{Möller, Per and Björck, Svante and Dowling, T.P.F. and Hammarlund, Dan and Jakobsson, Martin and Ljung, Karl and Lund, Martin and Paradeisis-Stathis, Savvas}},
  issn         = {{0197-9337}},
  keywords     = {{Dalarna; ice sheet recession; glacial geomorphology; streamlined terrain; ribbed moraine; glaciofluvial deposits; lake isolation; drainage re-routing; lake bathymetry; ice-dammed lake; shoreline displacement; Baltic Basin; glacio-isostatic rebound; LiDAR; digital terrain models}},
  language     = {{eng}},
  month        = {{09}},
  pages        = {{3515--3545}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Earth Surface Processes and Landforms}},
  title        = {{Deglaciation history and subsequent lake dynamics in the Siljan region, south-central Sweden, based on new LiDAR evidence and sediment records}},
  url          = {{http://dx.doi.org/10.1002/esp.5471}},
  doi          = {{10.1002/esp.5471}},
  volume       = {{47}},
  year         = {{2022}},
}