Cool kaolins in Finland
We use D/H and 18O/16O ratios to explore the age of kaolins on the Fennoscandian Shield. Sub-Cretaceous kaolins in southern Scandinavia have isotopic compositions indicative of weathering under warm mean annual temperatures (MATs) of > 15 °C. Deep kaolins on the shield surface in Finland previous...
Published in: | Palaeogeography, Palaeoclimatology, Palaeoecology |
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ftuglasgow:oai:eprints.gla.ac.uk:90564 2023-05-15T15:06:03+02:00 Cool kaolins in Finland Gilg, H.A. Hall, A.M. Ebert, K. Fallick, A.E. 2013-12-15 http://eprints.gla.ac.uk/90564/ unknown Elsevier BV Gilg, H.A., Hall, A.M., Ebert, K. and Fallick, A.E. <http://eprints.gla.ac.uk/view/author/1774.html> (2013) Cool kaolins in Finland. Palaeogeography, Palaeoclimatology, Palaeoecology <http://eprints.gla.ac.uk/view/journal_volume/Palaeogeography,_Palaeoclimatology,_Palaeoecology.html>, 392, pp. 454-462. (doi:10.1016/j.palaeo.2013.09.030 <http://dx.doi.org/10.1016/j.palaeo.2013.09.030>) Articles PeerReviewed 2013 ftuglasgow https://doi.org/10.1016/j.palaeo.2013.09.030 2021-09-23T23:05:49Z We use D/H and 18O/16O ratios to explore the age of kaolins on the Fennoscandian Shield. Sub-Cretaceous kaolins in southern Scandinavia have isotopic compositions indicative of weathering under warm mean annual temperatures (MATs) of > 15 °C. Deep kaolins on the shield surface in Finland previously also have been regarded as products of humid tropical weathering of Mesoproterozoic to Eocene age. New oxygen and hydrogen isotope ratios indicate, however, weathering by cool groundwater under MATs of 13–15 °C. Isotope ratios are also not consistent with deep (> 1 km) burial by cover rocks, indicating that a very old age for the weathering is unlikely. Palaeotemperatures are below Cretaceous MATs, yet substantially above Plio-Pleistocene MATs. Comparisons with palaeotemperatures in N Europe and around the Arctic Ocean indicate that the Finnish kaolins developed on the shield surface in the Palaeogene or, alternatively, Miocene. Deep weathering was selectively developed in highly fractured shield rocks and took place in response to latest Cretaceous and Palaeogene uplift and after stripping of Palaeozoic cover rocks. The cool kaolins in Finland indicate that previous routine attributions of kaolinitic weathering products in the geological record to humid tropical environments should be closely scrutinised. Article in Journal/Newspaper Arctic Arctic Ocean Fennoscandian University of Glasgow: Enlighten - Publications Arctic Arctic Ocean Palaeogeography, Palaeoclimatology, Palaeoecology 392 454 462 |
institution |
Open Polar |
collection |
University of Glasgow: Enlighten - Publications |
op_collection_id |
ftuglasgow |
language |
unknown |
description |
We use D/H and 18O/16O ratios to explore the age of kaolins on the Fennoscandian Shield. Sub-Cretaceous kaolins in southern Scandinavia have isotopic compositions indicative of weathering under warm mean annual temperatures (MATs) of > 15 °C. Deep kaolins on the shield surface in Finland previously also have been regarded as products of humid tropical weathering of Mesoproterozoic to Eocene age. New oxygen and hydrogen isotope ratios indicate, however, weathering by cool groundwater under MATs of 13–15 °C. Isotope ratios are also not consistent with deep (> 1 km) burial by cover rocks, indicating that a very old age for the weathering is unlikely. Palaeotemperatures are below Cretaceous MATs, yet substantially above Plio-Pleistocene MATs. Comparisons with palaeotemperatures in N Europe and around the Arctic Ocean indicate that the Finnish kaolins developed on the shield surface in the Palaeogene or, alternatively, Miocene. Deep weathering was selectively developed in highly fractured shield rocks and took place in response to latest Cretaceous and Palaeogene uplift and after stripping of Palaeozoic cover rocks. The cool kaolins in Finland indicate that previous routine attributions of kaolinitic weathering products in the geological record to humid tropical environments should be closely scrutinised. |
format |
Article in Journal/Newspaper |
author |
Gilg, H.A. Hall, A.M. Ebert, K. Fallick, A.E. |
spellingShingle |
Gilg, H.A. Hall, A.M. Ebert, K. Fallick, A.E. Cool kaolins in Finland |
author_facet |
Gilg, H.A. Hall, A.M. Ebert, K. Fallick, A.E. |
author_sort |
Gilg, H.A. |
title |
Cool kaolins in Finland |
title_short |
Cool kaolins in Finland |
title_full |
Cool kaolins in Finland |
title_fullStr |
Cool kaolins in Finland |
title_full_unstemmed |
Cool kaolins in Finland |
title_sort |
cool kaolins in finland |
publisher |
Elsevier BV |
publishDate |
2013 |
url |
http://eprints.gla.ac.uk/90564/ |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Fennoscandian |
genre_facet |
Arctic Arctic Ocean Fennoscandian |
op_relation |
Gilg, H.A., Hall, A.M., Ebert, K. and Fallick, A.E. <http://eprints.gla.ac.uk/view/author/1774.html> (2013) Cool kaolins in Finland. Palaeogeography, Palaeoclimatology, Palaeoecology <http://eprints.gla.ac.uk/view/journal_volume/Palaeogeography,_Palaeoclimatology,_Palaeoecology.html>, 392, pp. 454-462. (doi:10.1016/j.palaeo.2013.09.030 <http://dx.doi.org/10.1016/j.palaeo.2013.09.030>) |
op_doi |
https://doi.org/10.1016/j.palaeo.2013.09.030 |
container_title |
Palaeogeography, Palaeoclimatology, Palaeoecology |
container_volume |
392 |
container_start_page |
454 |
op_container_end_page |
462 |
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1766337718129786880 |