When the River Began—The Formation of River Motala Ström and Human Presence in the Early Holocene, Sweden
| Autor: | Jens Heimdahl, Jan Risberg, Fredrik Molin, Jonas Bergman, Fredrik Hallgren, Anna Plikk, Linus Hagberg |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
congenital
hereditary and neonatal diseases and abnormalities 010506 paleontology Kanaljorden river formation process lcsh:GN281-289 Structural basin 010502 geochemistry & geophysics 01 natural sciences Tectonic uplift lcsh:Stratigraphy Earth and Planetary Sciences (miscellaneous) cardiovascular diseases Holocene 0105 earth and related environmental sciences Earth-Surface Processes lcsh:QE640-699 geography geography.geographical_feature_category Ancient lake shoreline displacement Macrofossil Water level surgical procedures operative River Motala Ström cardiovascular system lcsh:Human evolution Physical geography Strandvägen Ice sheet Lake Vättern human activities Geology Mesolithic Marine transgression |
| Zdroj: | Quaternary, Vol 3, Iss 25, p 25 (2020) Quaternary Volume 3 Issue 3 |
| Popis: | In conjunction with the extensive archaeological projects conducted at the current outlet of Sweden&rsquo s second largest lake, Lake Vä ttern, macrofossil, pollen and diatom records have been studied from 14C-dated lake and river sediments from River Motala Strö m in Motala and Lake Boren. These investigations have revealed sedimentary evidence of the Yoldia Sea regression, the Ancient Lake Vä ttern transgression, and the following stepwise river formation process. Around 9000 cal BC, two small kettlehole basins at Strandvä gen and Kanaljorden became isolated from the Baltic basin. As the ice sheet retreated further north, the isostatic uplift isolated the Vä ttern basin from the Baltic basin. Due to the uneven isostatic uplift, the basin tilted toward the south, and the Ancient Lake Vä ttern transgression started in Motala. The threshold in Motala at 92.5 m a.s.l. was reached around 7200 cal BC, and River Motala Strö m was formed. 14C-dated diatom records from Lake Boren, and shoreline deposits in Motala, confirm this event. The water level in Lake Vä ttern initially fell around 1.5 m, and around 5800 cal BC, a second erosional event cut down the threshold to modern day level. At this time, the Late Mesolithic settlements in Motala were established and expanded. |
| Databáze: | OpenAIRE |
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