Reconnaissance Pb-Pb dating of single mineral phases by the step-leaching method: results from the Caledonides of East Greenland
Reconnaissance Pb-Pb step-leaching analyses have been carried out on garnet and kyanite from the Krummedal supracrustal sequence in East Greenland, yielding respectively Neoproterozoic and Caledonian ages. These data support previous analyses suggesting that the Krummedal supracrustal sequence, wide...
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ftjgeusbullet:oai:geusjournals.org:article/4819 2023-05-15T16:03:14+02:00 Reconnaissance Pb-Pb dating of single mineral phases by the step-leaching method: results from the Caledonides of East Greenland Thrane, Kristine 2004-12-30 application/pdf https://geusbulletin.org/index.php/geusb/article/view/4819 https://doi.org/10.34194/geusb.v6.4819 eng eng Geological Survey of Denmark and Greenland (GEUS) https://geusbulletin.org/index.php/geusb/article/view/4819/10455 https://geusbulletin.org/index.php/geusb/article/view/4819 doi:10.34194/geusb.v6.4819 GEUS Bulletin; Vol. 6 (2004): East Greenland Caledonides, stratigraphy, structure and geochronology; 67-76 2597-2154 2597-2162 Caledonian East Greenland geochronology Neoproterozoic step-leaching info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article. 2004 ftjgeusbullet https://doi.org/10.34194/geusb.v6.4819 2022-03-15T17:22:15Z Reconnaissance Pb-Pb step-leaching analyses have been carried out on garnet and kyanite from the Krummedal supracrustal sequence in East Greenland, yielding respectively Neoproterozoic and Caledonian ages. These data support previous analyses suggesting that the Krummedal supracrustal sequence, widespread in southern parts of the East Greenland Caledonides, was affected by both an early Neoproterozoic and a Caledonian thermal event. Titanite and apatite fractions from the underlying crystalline basement rocks were analysed in order to obtain metamorphic ages, as a contrast and supplement to the numerous existing protolith ages on orthogneisses. The titanite yielded a date of 486 ± 15 Ma which, if interpreted as a true age, is older than the usual range of Caledonian ages in East Greenland. The significance of this date is uncertain, but one possibility is that it reflects extension and subsidence taking place prior to Caledonian collision. The apatite, in contrast, yielded a very young Caledonian date of 392 ± 24 Ma that may reflect the cooling of the basement gneisses to < 500°C subsequent to collision. Article in Journal/Newspaper East Greenland Greenland GEUS Bulletin (Geological Survey of Denmark and Greenland) Greenland Geological Survey of Denmark and Greenland (GEUS) Bulletin 6 67 76 |
institution |
Open Polar |
collection |
GEUS Bulletin (Geological Survey of Denmark and Greenland) |
op_collection_id |
ftjgeusbullet |
language |
English |
topic |
Caledonian East Greenland geochronology Neoproterozoic step-leaching |
spellingShingle |
Caledonian East Greenland geochronology Neoproterozoic step-leaching Thrane, Kristine Reconnaissance Pb-Pb dating of single mineral phases by the step-leaching method: results from the Caledonides of East Greenland |
topic_facet |
Caledonian East Greenland geochronology Neoproterozoic step-leaching |
description |
Reconnaissance Pb-Pb step-leaching analyses have been carried out on garnet and kyanite from the Krummedal supracrustal sequence in East Greenland, yielding respectively Neoproterozoic and Caledonian ages. These data support previous analyses suggesting that the Krummedal supracrustal sequence, widespread in southern parts of the East Greenland Caledonides, was affected by both an early Neoproterozoic and a Caledonian thermal event. Titanite and apatite fractions from the underlying crystalline basement rocks were analysed in order to obtain metamorphic ages, as a contrast and supplement to the numerous existing protolith ages on orthogneisses. The titanite yielded a date of 486 ± 15 Ma which, if interpreted as a true age, is older than the usual range of Caledonian ages in East Greenland. The significance of this date is uncertain, but one possibility is that it reflects extension and subsidence taking place prior to Caledonian collision. The apatite, in contrast, yielded a very young Caledonian date of 392 ± 24 Ma that may reflect the cooling of the basement gneisses to < 500°C subsequent to collision. |
format |
Article in Journal/Newspaper |
author |
Thrane, Kristine |
author_facet |
Thrane, Kristine |
author_sort |
Thrane, Kristine |
title |
Reconnaissance Pb-Pb dating of single mineral phases by the step-leaching method: results from the Caledonides of East Greenland |
title_short |
Reconnaissance Pb-Pb dating of single mineral phases by the step-leaching method: results from the Caledonides of East Greenland |
title_full |
Reconnaissance Pb-Pb dating of single mineral phases by the step-leaching method: results from the Caledonides of East Greenland |
title_fullStr |
Reconnaissance Pb-Pb dating of single mineral phases by the step-leaching method: results from the Caledonides of East Greenland |
title_full_unstemmed |
Reconnaissance Pb-Pb dating of single mineral phases by the step-leaching method: results from the Caledonides of East Greenland |
title_sort |
reconnaissance pb-pb dating of single mineral phases by the step-leaching method: results from the caledonides of east greenland |
publisher |
Geological Survey of Denmark and Greenland (GEUS) |
publishDate |
2004 |
url |
https://geusbulletin.org/index.php/geusb/article/view/4819 https://doi.org/10.34194/geusb.v6.4819 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
East Greenland Greenland |
genre_facet |
East Greenland Greenland |
op_source |
GEUS Bulletin; Vol. 6 (2004): East Greenland Caledonides, stratigraphy, structure and geochronology; 67-76 2597-2154 2597-2162 |
op_relation |
https://geusbulletin.org/index.php/geusb/article/view/4819/10455 https://geusbulletin.org/index.php/geusb/article/view/4819 doi:10.34194/geusb.v6.4819 |
op_doi |
https://doi.org/10.34194/geusb.v6.4819 |
container_title |
Geological Survey of Denmark and Greenland (GEUS) Bulletin |
container_volume |
6 |
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67 |
op_container_end_page |
76 |
_version_ |
1766398856334934016 |