The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition
Re-examination of the Skaergaard intrusion in the context of its regional setting, combined with new data from exploration drilling, has resulted in a revised structural model for the intrusion. It is modelled as an irregular box, c . 11 km from north to south, up to 8 km from east to west, and 3·4–...
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2004
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fthighwire:oai:open-archive.highwire.org:petrology:45/3/507 2023-05-15T16:03:42+02:00 The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition NIELSEN, TROELS F. D. 2004-03-01 00:00:00.0 text/html http://petrology.oxfordjournals.org/cgi/content/short/45/3/507 https://doi.org/10.1093/petrology/egg092 en eng Oxford University Press http://petrology.oxfordjournals.org/cgi/content/short/45/3/507 http://dx.doi.org/10.1093/petrology/egg092 Copyright (C) 2004, Oxford University Press ARTICLES TEXT 2004 fthighwire https://doi.org/10.1093/petrology/egg092 2013-05-27T23:35:32Z Re-examination of the Skaergaard intrusion in the context of its regional setting, combined with new data from exploration drilling, has resulted in a revised structural model for the intrusion. It is modelled as an irregular box, c . 11 km from north to south, up to 8 km from east to west, and 3·4–4 km from the lower to the upper contact. The walls of the intrusion are inferred to follow pre-existing and penecontemporaneous steep faults, and the floor and roof seem largely controlled by bedding planes in the host sediments and lavas, similar to regional sills. The suggested shape and volume are in agreement with published gravimetric modelling. Crystallization along all margins of the intrusion concentrated the evolving melt in the upper, central part of the intrusion, best visualized as an ‘onion-skin’ structure inside the box. The total volume is estimated to c . 280 ± 23 km3, of which 13·7% are referred to the Upper Border Series (UBS), 16·4% to the Marginal Border Series (MBS) and 69·9% to the Layered Series (LS). In the LS, the Lower Zone (LZ) is estimated to constitute 66·8%, the Middle Zone (MZ) 13·5% and the Upper Zone (UZ) 19·7%. The new volume relationships provide a mass balance estimate of the major and trace element bulk composition of the intrusion. The parental magma to the Skaergaard intrusion is similar to high-Ti East Greenland tholeiitic plateau basalts with Mg number c. 0.45. The intrusion represents the solidification of contemporary plateau basalt magma trapped and crystallized under closed-system conditions in a crustal reservoir at the developing East Greenland continental margin. Text East Greenland Greenland HighWire Press (Stanford University) Greenland Journal of Petrology 45 3 507 530 |
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HighWire Press (Stanford University) |
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English |
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ARTICLES |
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ARTICLES NIELSEN, TROELS F. D. The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition |
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ARTICLES |
description |
Re-examination of the Skaergaard intrusion in the context of its regional setting, combined with new data from exploration drilling, has resulted in a revised structural model for the intrusion. It is modelled as an irregular box, c . 11 km from north to south, up to 8 km from east to west, and 3·4–4 km from the lower to the upper contact. The walls of the intrusion are inferred to follow pre-existing and penecontemporaneous steep faults, and the floor and roof seem largely controlled by bedding planes in the host sediments and lavas, similar to regional sills. The suggested shape and volume are in agreement with published gravimetric modelling. Crystallization along all margins of the intrusion concentrated the evolving melt in the upper, central part of the intrusion, best visualized as an ‘onion-skin’ structure inside the box. The total volume is estimated to c . 280 ± 23 km3, of which 13·7% are referred to the Upper Border Series (UBS), 16·4% to the Marginal Border Series (MBS) and 69·9% to the Layered Series (LS). In the LS, the Lower Zone (LZ) is estimated to constitute 66·8%, the Middle Zone (MZ) 13·5% and the Upper Zone (UZ) 19·7%. The new volume relationships provide a mass balance estimate of the major and trace element bulk composition of the intrusion. The parental magma to the Skaergaard intrusion is similar to high-Ti East Greenland tholeiitic plateau basalts with Mg number c. 0.45. The intrusion represents the solidification of contemporary plateau basalt magma trapped and crystallized under closed-system conditions in a crustal reservoir at the developing East Greenland continental margin. |
format |
Text |
author |
NIELSEN, TROELS F. D. |
author_facet |
NIELSEN, TROELS F. D. |
author_sort |
NIELSEN, TROELS F. D. |
title |
The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition |
title_short |
The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition |
title_full |
The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition |
title_fullStr |
The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition |
title_full_unstemmed |
The Shape and Volume of the Skaergaard Intrusion, Greenland: Implications for Mass Balance and Bulk Composition |
title_sort |
shape and volume of the skaergaard intrusion, greenland: implications for mass balance and bulk composition |
publisher |
Oxford University Press |
publishDate |
2004 |
url |
http://petrology.oxfordjournals.org/cgi/content/short/45/3/507 https://doi.org/10.1093/petrology/egg092 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
East Greenland Greenland |
genre_facet |
East Greenland Greenland |
op_relation |
http://petrology.oxfordjournals.org/cgi/content/short/45/3/507 http://dx.doi.org/10.1093/petrology/egg092 |
op_rights |
Copyright (C) 2004, Oxford University Press |
op_doi |
https://doi.org/10.1093/petrology/egg092 |
container_title |
Journal of Petrology |
container_volume |
45 |
container_issue |
3 |
container_start_page |
507 |
op_container_end_page |
530 |
_version_ |
1766399392222281728 |