An Isotope and Trace Element Study of the East Greenland Tertiary Dyke Swarm: Constraints on Temporal and Spatial Evolution during Continental Rifting
Dykes of the East Greenland Tertiary dyke swarm can be divided into pre- and syn-break-up tholeiitic dykes, and post-break-up transitional dykes. Of the pre- and syn-break-up dykes, the most abundant group (Tholeiitic Series; TS) has major element compositions similar to the main part of the East Gr...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.513.580 2023-05-15T16:03:28+02:00 An Isotope and Trace Element Study of the East Greenland Tertiary Dyke Swarm: Constraints on Temporal and Spatial Evolution during Continental Rifting K. Hanghéj M. Storey O. Stecher The Pennsylvania State University CiteSeerX Archives 2000 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.513.580 http://petrology.oxfordjournals.org/content/44/11/2081.full.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.513.580 http://petrology.oxfordjournals.org/content/44/11/2081.full.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://petrology.oxfordjournals.org/content/44/11/2081.full.pdf text 2000 ftciteseerx 2016-01-08T09:46:00Z Dykes of the East Greenland Tertiary dyke swarm can be divided into pre- and syn-break-up tholeiitic dykes, and post-break-up transitional dykes. Of the pre- and syn-break-up dykes, the most abundant group (Tholeiitic Series; TS) has major element compositions similar to the main part of the East Greenland flood basalts. A group of high-MgO tholeiitic dykes (Picrite---Ankaramite Series; PAS) are much less common, and are equivalent to some of the oldest lavas of the East Greenland flood basalts. Isotopic compositions of the TS and PAS dykes partly overlap with those for Iceland, but Pb isotopic composi-tions extend to less radiogenic values than those seen in either Iceland or North Atlantic mid-ocean ridge basalt (MORB). The isotopically depleted source required to account for this isotopic variation is interpreted as subcontinental lithospheric mantle with low 87Sr/86Sr and 206Pb/204Pb and high eNd. The post-break-up Transitional Series (TRANS) dykes are iso-topically distinct from Iceland and MORB, and are interpreted as the products of contamination of Iceland plume melts with continental crust. Comparison of the Nd---Sr---Pb isotopic and trace element compositions of dykes from different segments of the East Greenland margin indicates that there is no systematic compositional change with distance from the presumed proto-Icelandic plume centre. This suggests that a northward-increasing crustal thickness observed offshore may be attributed to active upwelling rather than a systematic rise in temperature towards the plume centre. KEY WORDS: isotopes; trace elements; mantle sources; mantle melting Text East Greenland Greenland Iceland North Atlantic Unknown Greenland |
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English |
description |
Dykes of the East Greenland Tertiary dyke swarm can be divided into pre- and syn-break-up tholeiitic dykes, and post-break-up transitional dykes. Of the pre- and syn-break-up dykes, the most abundant group (Tholeiitic Series; TS) has major element compositions similar to the main part of the East Greenland flood basalts. A group of high-MgO tholeiitic dykes (Picrite---Ankaramite Series; PAS) are much less common, and are equivalent to some of the oldest lavas of the East Greenland flood basalts. Isotopic compositions of the TS and PAS dykes partly overlap with those for Iceland, but Pb isotopic composi-tions extend to less radiogenic values than those seen in either Iceland or North Atlantic mid-ocean ridge basalt (MORB). The isotopically depleted source required to account for this isotopic variation is interpreted as subcontinental lithospheric mantle with low 87Sr/86Sr and 206Pb/204Pb and high eNd. The post-break-up Transitional Series (TRANS) dykes are iso-topically distinct from Iceland and MORB, and are interpreted as the products of contamination of Iceland plume melts with continental crust. Comparison of the Nd---Sr---Pb isotopic and trace element compositions of dykes from different segments of the East Greenland margin indicates that there is no systematic compositional change with distance from the presumed proto-Icelandic plume centre. This suggests that a northward-increasing crustal thickness observed offshore may be attributed to active upwelling rather than a systematic rise in temperature towards the plume centre. KEY WORDS: isotopes; trace elements; mantle sources; mantle melting |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
K. Hanghéj M. Storey O. Stecher |
spellingShingle |
K. Hanghéj M. Storey O. Stecher An Isotope and Trace Element Study of the East Greenland Tertiary Dyke Swarm: Constraints on Temporal and Spatial Evolution during Continental Rifting |
author_facet |
K. Hanghéj M. Storey O. Stecher |
author_sort |
K. Hanghéj |
title |
An Isotope and Trace Element Study of the East Greenland Tertiary Dyke Swarm: Constraints on Temporal and Spatial Evolution during Continental Rifting |
title_short |
An Isotope and Trace Element Study of the East Greenland Tertiary Dyke Swarm: Constraints on Temporal and Spatial Evolution during Continental Rifting |
title_full |
An Isotope and Trace Element Study of the East Greenland Tertiary Dyke Swarm: Constraints on Temporal and Spatial Evolution during Continental Rifting |
title_fullStr |
An Isotope and Trace Element Study of the East Greenland Tertiary Dyke Swarm: Constraints on Temporal and Spatial Evolution during Continental Rifting |
title_full_unstemmed |
An Isotope and Trace Element Study of the East Greenland Tertiary Dyke Swarm: Constraints on Temporal and Spatial Evolution during Continental Rifting |
title_sort |
isotope and trace element study of the east greenland tertiary dyke swarm: constraints on temporal and spatial evolution during continental rifting |
publishDate |
2000 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.513.580 http://petrology.oxfordjournals.org/content/44/11/2081.full.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
East Greenland Greenland Iceland North Atlantic |
genre_facet |
East Greenland Greenland Iceland North Atlantic |
op_source |
http://petrology.oxfordjournals.org/content/44/11/2081.full.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.513.580 http://petrology.oxfordjournals.org/content/44/11/2081.full.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766399141555994624 |