A 40Ar/39Ar and U/Pb isotopic study of the Ilímaussaq complex, South Greenland: Implications for the 40K decay constant and for the duration of magmatic activity in a peralkaline complex
Magmatism in the Gardar Province, South Greenland, is related to two main rifting events at 1280 Ma and 1180 to 1140 Ma. Little is known about the duration of the magmatic activity in a specific complex. The Ilímaussaq intrusion belongs to the second period of rifting and comprises an extraordinary...
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Online Access: | http://hdl.handle.net/10281/3737 https://doi.org/10.1016/j.chemgeo.2005.10.004 |
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ftunivmilanobic:oai:boa.unimib.it:10281/3737 2024-04-14T08:12:21+00:00 A 40Ar/39Ar and U/Pb isotopic study of the Ilímaussaq complex, South Greenland: Implications for the 40K decay constant and for the duration of magmatic activity in a peralkaline complex Krumrei, TV Marks, MAW Markl, G. VILLA, IGOR MARIA Krumrei, T Villa, I Marks, M Markl, G 2006 http://hdl.handle.net/10281/3737 https://doi.org/10.1016/j.chemgeo.2005.10.004 eng eng ELSEVIER SCIENCE BV country:NL info:eu-repo/semantics/altIdentifier/wos/WOS:000236661700008 volume:227 issue:3-4 firstpage:258 lastpage:273 journal:CHEMICAL GEOLOGY http://hdl.handle.net/10281/3737 doi:10.1016/j.chemgeo.2005.10.004 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-33644948092 geochronology Greenland decay constant GEO/08 - GEOCHIMICA E VULCANOLOGIA info:eu-repo/semantics/article 2006 ftunivmilanobic https://doi.org/10.1016/j.chemgeo.2005.10.004 2024-03-21T16:26:14Z Magmatism in the Gardar Province, South Greenland, is related to two main rifting events at 1280 Ma and 1180 to 1140 Ma. Little is known about the duration of the magmatic activity in a specific complex. The Ilímaussaq intrusion belongs to the second period of rifting and comprises an extraordinary diversity of granitic and syenitic rock types, which intruded and fractionated in three successive magmatic events. As the intrusion contains some of the most evolved, incompatible element-rich rocks on Earth, it was chosen for a detailed geochronological study to quantify the duration of melt production, intrusion, fractionation and cooling. Amphiboles, which are abundant in all rock types, including pegmatites and late magmatic veins, were dated using the 40 Ar/ 39 Ar technique. Since the solidus temperature of the most evolved melts is below the closure temperature of amphibole, and no later heating event occurred, the 40 Ar/ 39 Ar ages reflect the magmatic crystallisation and can be used to determine the duration of igneous differentiation. The 40 Ar/ 39 Ar plateau ages range between 1142.6 ± 2.2 Ma and 1152.3 ± 3.7 Ma using the Steiger and Jäger [Steiger, R.H. and Jäger, E., (1977). Subcommision on Geochronology: Convention on the use of decay constants in geo- and cosmochronology. Earth Planet. Sci. Lett. 36, 359-362.] 40 K decay constant. These ages are younger than an U-Pb age of 1160 ± 5 Ma on baddeleyite from the first magma batch. Our results indicate that the 40 K decay constant of Steiger and Jäger may be too high; a lambda similar to that proposed by Kwon et al. [Kwon, J., Min, K., Bickel, P. and Renne, P.R., (2002). Statistical methods for jointly estimating decay constant of 40 K and age of a dating standard. Math. Geol. 34, 457-474.] is required to make the 40 Ar/ 39 Ar match the U-Pb age. © 2005 Elsevier B.V. All rights reserved. Magmatism in the Gardar Province, South Greenland, is related to two main rifting events at 1280 Ma and 1180 to 1140 Ma. Little is known about the duration of the ... Article in Journal/Newspaper Greenland renne Università degli Studi di Milano-Bicocca: BOA (Bicocca Open Archive) Greenland Lambda ENVELOPE(-62.983,-62.983,-64.300,-64.300) Renne ENVELOPE(9.698,9.698,63.505,63.505) Chemical Geology 227 3-4 258 273 |
institution |
Open Polar |
collection |
Università degli Studi di Milano-Bicocca: BOA (Bicocca Open Archive) |
op_collection_id |
ftunivmilanobic |
language |
English |
topic |
geochronology Greenland decay constant GEO/08 - GEOCHIMICA E VULCANOLOGIA |
spellingShingle |
geochronology Greenland decay constant GEO/08 - GEOCHIMICA E VULCANOLOGIA Krumrei, TV Marks, MAW Markl, G. VILLA, IGOR MARIA A 40Ar/39Ar and U/Pb isotopic study of the Ilímaussaq complex, South Greenland: Implications for the 40K decay constant and for the duration of magmatic activity in a peralkaline complex |
topic_facet |
geochronology Greenland decay constant GEO/08 - GEOCHIMICA E VULCANOLOGIA |
description |
Magmatism in the Gardar Province, South Greenland, is related to two main rifting events at 1280 Ma and 1180 to 1140 Ma. Little is known about the duration of the magmatic activity in a specific complex. The Ilímaussaq intrusion belongs to the second period of rifting and comprises an extraordinary diversity of granitic and syenitic rock types, which intruded and fractionated in three successive magmatic events. As the intrusion contains some of the most evolved, incompatible element-rich rocks on Earth, it was chosen for a detailed geochronological study to quantify the duration of melt production, intrusion, fractionation and cooling. Amphiboles, which are abundant in all rock types, including pegmatites and late magmatic veins, were dated using the 40 Ar/ 39 Ar technique. Since the solidus temperature of the most evolved melts is below the closure temperature of amphibole, and no later heating event occurred, the 40 Ar/ 39 Ar ages reflect the magmatic crystallisation and can be used to determine the duration of igneous differentiation. The 40 Ar/ 39 Ar plateau ages range between 1142.6 ± 2.2 Ma and 1152.3 ± 3.7 Ma using the Steiger and Jäger [Steiger, R.H. and Jäger, E., (1977). Subcommision on Geochronology: Convention on the use of decay constants in geo- and cosmochronology. Earth Planet. Sci. Lett. 36, 359-362.] 40 K decay constant. These ages are younger than an U-Pb age of 1160 ± 5 Ma on baddeleyite from the first magma batch. Our results indicate that the 40 K decay constant of Steiger and Jäger may be too high; a lambda similar to that proposed by Kwon et al. [Kwon, J., Min, K., Bickel, P. and Renne, P.R., (2002). Statistical methods for jointly estimating decay constant of 40 K and age of a dating standard. Math. Geol. 34, 457-474.] is required to make the 40 Ar/ 39 Ar match the U-Pb age. © 2005 Elsevier B.V. All rights reserved. Magmatism in the Gardar Province, South Greenland, is related to two main rifting events at 1280 Ma and 1180 to 1140 Ma. Little is known about the duration of the ... |
author2 |
Krumrei, T Villa, I Marks, M Markl, G |
format |
Article in Journal/Newspaper |
author |
Krumrei, TV Marks, MAW Markl, G. VILLA, IGOR MARIA |
author_facet |
Krumrei, TV Marks, MAW Markl, G. VILLA, IGOR MARIA |
author_sort |
Krumrei, TV |
title |
A 40Ar/39Ar and U/Pb isotopic study of the Ilímaussaq complex, South Greenland: Implications for the 40K decay constant and for the duration of magmatic activity in a peralkaline complex |
title_short |
A 40Ar/39Ar and U/Pb isotopic study of the Ilímaussaq complex, South Greenland: Implications for the 40K decay constant and for the duration of magmatic activity in a peralkaline complex |
title_full |
A 40Ar/39Ar and U/Pb isotopic study of the Ilímaussaq complex, South Greenland: Implications for the 40K decay constant and for the duration of magmatic activity in a peralkaline complex |
title_fullStr |
A 40Ar/39Ar and U/Pb isotopic study of the Ilímaussaq complex, South Greenland: Implications for the 40K decay constant and for the duration of magmatic activity in a peralkaline complex |
title_full_unstemmed |
A 40Ar/39Ar and U/Pb isotopic study of the Ilímaussaq complex, South Greenland: Implications for the 40K decay constant and for the duration of magmatic activity in a peralkaline complex |
title_sort |
40ar/39ar and u/pb isotopic study of the ilímaussaq complex, south greenland: implications for the 40k decay constant and for the duration of magmatic activity in a peralkaline complex |
publisher |
ELSEVIER SCIENCE BV |
publishDate |
2006 |
url |
http://hdl.handle.net/10281/3737 https://doi.org/10.1016/j.chemgeo.2005.10.004 |
long_lat |
ENVELOPE(-62.983,-62.983,-64.300,-64.300) ENVELOPE(9.698,9.698,63.505,63.505) |
geographic |
Greenland Lambda Renne |
geographic_facet |
Greenland Lambda Renne |
genre |
Greenland renne |
genre_facet |
Greenland renne |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000236661700008 volume:227 issue:3-4 firstpage:258 lastpage:273 journal:CHEMICAL GEOLOGY http://hdl.handle.net/10281/3737 doi:10.1016/j.chemgeo.2005.10.004 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-33644948092 |
op_doi |
https://doi.org/10.1016/j.chemgeo.2005.10.004 |
container_title |
Chemical Geology |
container_volume |
227 |
container_issue |
3-4 |
container_start_page |
258 |
op_container_end_page |
273 |
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1796310158700183552 |