Peneplains and tectonics in North-East Greenland after opening of the North-East Atlantic
Elevated plateaus with deeply incised valleys characterise elevated, passive continental margins (EPCMs) in all climate zones. These features are, however, a topic of debate regarding when and how the large-scale landscapes formed. We have investigated and mapped the partly glaciated landscape of No...
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Uppsala universitet, Kulturgeografiska institutionen
2021
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ftuppsalauniv:oai:DiVA.org:uu-442281 2023-05-15T16:03:37+02:00 Peneplains and tectonics in North-East Greenland after opening of the North-East Atlantic Bonow, Johan M. Japsen, Peter 2021 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-442281 https://doi.org/10.34194/geusb.v45.5297 eng eng Uppsala universitet, Kulturgeografiska institutionen Geovisiona AB, Bro, Sweden.;Geol Survey Denmark & Greenland GE Us, Copenhagen, Denmark. Geol Survey Denmark & Greenland GE Us, Copenhagen, Denmark. Geological Survey of Denmark and Greenland , 2021, 45:1, GEUS Bulletin, 2597-2154, 2021, 45:1, orcid:0000-0003-0547-0565 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-442281 doi:10.34194/geusb.v45.5297 ISI:000634473700001 info:eu-repo/semantics/openAccess Cenozoic denudation chronology passive margin stratigraphic landscape analysis uplift Geology Geologi Physical Geography Naturgeografi Article in journal info:eu-repo/semantics/article text 2021 ftuppsalauniv https://doi.org/10.34194/geusb.v45.5297 2023-02-23T22:00:07Z Elevated plateaus with deeply incised valleys characterise elevated, passive continental margins (EPCMs) in all climate zones. These features are, however, a topic of debate regarding when and how the large-scale landscapes formed. We have investigated and mapped the partly glaciated landscape of North-East Greenland (70-78 degrees N). The area consists of crystalline basement and Palaeozoic-Mesozoic rift basins, capped by Palaeogene basalts that erupted during the northeast Atlantic break-up. Our stratigraphic landscape analysis reveals a typical EPCM dominated by two elevated erosion surfaces, extending 200 km east-west and 900 km north-south. The low-relief Upper Planation Surface (UPS; c. 2 km above sea level) cuts across basement and Palaeogene basalts, indicating that it was graded to base level defined by the Atlantic Ocean in post-basalt times and subsequently uplifted. The UPS formed prior to the deposition of mid-Miocene lavas that rest on it, south of the study area. In the interior basement terrains, the Lower Planation Surface (LPS) forms fluvial valley benches at c. 1 km above sea level, incised below the UPS. The LPS is thus younger than the UPS, which implies that it formed post mid-Miocene. Towards the coast, the valley benches merge to form a coherent surface that defines flat-topped mountains. This shows that the LPS was graded to near sea level and was subsequently uplifted. Hence, both the UPS and the LPS formed as pene-plains - erosion surfaces graded to base level. The fluvial valley benches associated with the LPS further indicates that full glacial conditions were only established after the uplift of the LPS in the early Pliocene (c. 5 Ma). The uplift of the LPS led to re-exposure of a Mesozoic etch surface. We conclude that episodes of late Neogene tectonic uplift shaped the stepped landscape and elevated topography in North-East Greenland. Article in Journal/Newspaper East Greenland Greenland North East Atlantic Northeast Atlantic Uppsala University: Publications (DiVA) Greenland GEUS Bulletin 45 1 |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
Cenozoic denudation chronology passive margin stratigraphic landscape analysis uplift Geology Geologi Physical Geography Naturgeografi |
spellingShingle |
Cenozoic denudation chronology passive margin stratigraphic landscape analysis uplift Geology Geologi Physical Geography Naturgeografi Bonow, Johan M. Japsen, Peter Peneplains and tectonics in North-East Greenland after opening of the North-East Atlantic |
topic_facet |
Cenozoic denudation chronology passive margin stratigraphic landscape analysis uplift Geology Geologi Physical Geography Naturgeografi |
description |
Elevated plateaus with deeply incised valleys characterise elevated, passive continental margins (EPCMs) in all climate zones. These features are, however, a topic of debate regarding when and how the large-scale landscapes formed. We have investigated and mapped the partly glaciated landscape of North-East Greenland (70-78 degrees N). The area consists of crystalline basement and Palaeozoic-Mesozoic rift basins, capped by Palaeogene basalts that erupted during the northeast Atlantic break-up. Our stratigraphic landscape analysis reveals a typical EPCM dominated by two elevated erosion surfaces, extending 200 km east-west and 900 km north-south. The low-relief Upper Planation Surface (UPS; c. 2 km above sea level) cuts across basement and Palaeogene basalts, indicating that it was graded to base level defined by the Atlantic Ocean in post-basalt times and subsequently uplifted. The UPS formed prior to the deposition of mid-Miocene lavas that rest on it, south of the study area. In the interior basement terrains, the Lower Planation Surface (LPS) forms fluvial valley benches at c. 1 km above sea level, incised below the UPS. The LPS is thus younger than the UPS, which implies that it formed post mid-Miocene. Towards the coast, the valley benches merge to form a coherent surface that defines flat-topped mountains. This shows that the LPS was graded to near sea level and was subsequently uplifted. Hence, both the UPS and the LPS formed as pene-plains - erosion surfaces graded to base level. The fluvial valley benches associated with the LPS further indicates that full glacial conditions were only established after the uplift of the LPS in the early Pliocene (c. 5 Ma). The uplift of the LPS led to re-exposure of a Mesozoic etch surface. We conclude that episodes of late Neogene tectonic uplift shaped the stepped landscape and elevated topography in North-East Greenland. |
format |
Article in Journal/Newspaper |
author |
Bonow, Johan M. Japsen, Peter |
author_facet |
Bonow, Johan M. Japsen, Peter |
author_sort |
Bonow, Johan M. |
title |
Peneplains and tectonics in North-East Greenland after opening of the North-East Atlantic |
title_short |
Peneplains and tectonics in North-East Greenland after opening of the North-East Atlantic |
title_full |
Peneplains and tectonics in North-East Greenland after opening of the North-East Atlantic |
title_fullStr |
Peneplains and tectonics in North-East Greenland after opening of the North-East Atlantic |
title_full_unstemmed |
Peneplains and tectonics in North-East Greenland after opening of the North-East Atlantic |
title_sort |
peneplains and tectonics in north-east greenland after opening of the north-east atlantic |
publisher |
Uppsala universitet, Kulturgeografiska institutionen |
publishDate |
2021 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-442281 https://doi.org/10.34194/geusb.v45.5297 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
East Greenland Greenland North East Atlantic Northeast Atlantic |
genre_facet |
East Greenland Greenland North East Atlantic Northeast Atlantic |
op_relation |
, 2021, 45:1, GEUS Bulletin, 2597-2154, 2021, 45:1, orcid:0000-0003-0547-0565 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-442281 doi:10.34194/geusb.v45.5297 ISI:000634473700001 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.34194/geusb.v45.5297 |
container_title |
GEUS Bulletin |
container_volume |
45 |
container_issue |
1 |
_version_ |
1766399306045063168 |