Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia
The Rum Igneous Centre comprises two early marginal felsic complexes (the Northern Marginal Zone and the Southern Mountains Zone), along with the later central ultrabasic–basic layered intrusions. These marginal complexes represent the remnants of near-surface to eruptive felsic magmatism associated...
Published in: | Geological Magazine |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2009
|
Subjects: | |
Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/early-mafic-magmatism-and-crustal-anatexis-on-the-isle-of-rum-evidence-from-the-am-mam-intrusion-breccia(c12bf68a-ed7b-4536-9aa1-f628e1d3b27a).html https://doi.org/10.1017/S0016756808005864 http://www.scopus.com/inward/record.url?scp=70349392624&partnerID=8YFLogxK |
id |
ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/c12bf68a-ed7b-4536-9aa1-f628e1d3b27a |
---|---|
record_format |
openpolar |
spelling |
ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/c12bf68a-ed7b-4536-9aa1-f628e1d3b27a 2023-05-15T17:30:53+02:00 Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia Nicoll, Graeme Holness, Marian Troll, Valentin Donaldson, Colin Henry Holohan, Eoghan Emeleus, C. H. Chew, David 2009-05 https://risweb.st-andrews.ac.uk/portal/en/researchoutput/early-mafic-magmatism-and-crustal-anatexis-on-the-isle-of-rum-evidence-from-the-am-mam-intrusion-breccia(c12bf68a-ed7b-4536-9aa1-f628e1d3b27a).html https://doi.org/10.1017/S0016756808005864 http://www.scopus.com/inward/record.url?scp=70349392624&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Nicoll , G , Holness , M , Troll , V , Donaldson , C H , Holohan , E , Emeleus , C H & Chew , D 2009 , ' Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia ' , Geological Magazine , vol. 146 , no. 3 , pp. 368-381 . https://doi.org/10.1017/S0016756808005864 North Atlantic Igneous Province Isle of Rum elsic magmas intrusion breccia geochemistry magma–crust interaction article 2009 ftunstandrewcris https://doi.org/10.1017/S0016756808005864 2022-06-02T07:39:48Z The Rum Igneous Centre comprises two early marginal felsic complexes (the Northern Marginal Zone and the Southern Mountains Zone), along with the later central ultrabasic–basic layered intrusions. These marginal complexes represent the remnants of near-surface to eruptive felsic magmatism associated with caldera collapse, examples of which are rare in the North Atlantic Igneous Province. Rock units include intra-caldera collapse breccias, rhyolitic ignimbrite deposits and shallow-level felsic intrusions, as well the enigmatic ‘Am Màm intrusion breccia’. The latter comprises a dacitic matrix enclosing lobate basaltic inclusions (~1–15 cm) and a variety of clasts, ranging from millimetres to tens of metres in diameter. These clasts comprise Lewisian gneiss, Torridonian sandstone and coarse gabbro. Detailed re-mapping of the Am Màm intrusion breccia has shown its timing of emplacement as syn-caldera, rather than pre-caldera as previously thought. Textural analysis of entrained clasts and adjacent, uplifted country rocks has revealed their thermal metamorphism by early mafic intrusions at greater depth than their present structural position. These findings provide a window into the evolution of the early mafic magmas responsible for driving felsic magmatism on Rum. Our data help constrain some of the physical parameters of this early magma–crust interaction and place it within the geochemical evolution of the Rum Centre. Article in Journal/Newspaper North Atlantic University of St Andrews: Research Portal Geological Magazine 146 3 368 381 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
North Atlantic Igneous Province Isle of Rum elsic magmas intrusion breccia geochemistry magma–crust interaction |
spellingShingle |
North Atlantic Igneous Province Isle of Rum elsic magmas intrusion breccia geochemistry magma–crust interaction Nicoll, Graeme Holness, Marian Troll, Valentin Donaldson, Colin Henry Holohan, Eoghan Emeleus, C. H. Chew, David Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia |
topic_facet |
North Atlantic Igneous Province Isle of Rum elsic magmas intrusion breccia geochemistry magma–crust interaction |
description |
The Rum Igneous Centre comprises two early marginal felsic complexes (the Northern Marginal Zone and the Southern Mountains Zone), along with the later central ultrabasic–basic layered intrusions. These marginal complexes represent the remnants of near-surface to eruptive felsic magmatism associated with caldera collapse, examples of which are rare in the North Atlantic Igneous Province. Rock units include intra-caldera collapse breccias, rhyolitic ignimbrite deposits and shallow-level felsic intrusions, as well the enigmatic ‘Am Màm intrusion breccia’. The latter comprises a dacitic matrix enclosing lobate basaltic inclusions (~1–15 cm) and a variety of clasts, ranging from millimetres to tens of metres in diameter. These clasts comprise Lewisian gneiss, Torridonian sandstone and coarse gabbro. Detailed re-mapping of the Am Màm intrusion breccia has shown its timing of emplacement as syn-caldera, rather than pre-caldera as previously thought. Textural analysis of entrained clasts and adjacent, uplifted country rocks has revealed their thermal metamorphism by early mafic intrusions at greater depth than their present structural position. These findings provide a window into the evolution of the early mafic magmas responsible for driving felsic magmatism on Rum. Our data help constrain some of the physical parameters of this early magma–crust interaction and place it within the geochemical evolution of the Rum Centre. |
format |
Article in Journal/Newspaper |
author |
Nicoll, Graeme Holness, Marian Troll, Valentin Donaldson, Colin Henry Holohan, Eoghan Emeleus, C. H. Chew, David |
author_facet |
Nicoll, Graeme Holness, Marian Troll, Valentin Donaldson, Colin Henry Holohan, Eoghan Emeleus, C. H. Chew, David |
author_sort |
Nicoll, Graeme |
title |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia |
title_short |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia |
title_full |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia |
title_fullStr |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia |
title_full_unstemmed |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia |
title_sort |
early mafic magmatism and crustal anatexis on the isle of rum: evidence from the am mam intrusion breccia |
publishDate |
2009 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/early-mafic-magmatism-and-crustal-anatexis-on-the-isle-of-rum-evidence-from-the-am-mam-intrusion-breccia(c12bf68a-ed7b-4536-9aa1-f628e1d3b27a).html https://doi.org/10.1017/S0016756808005864 http://www.scopus.com/inward/record.url?scp=70349392624&partnerID=8YFLogxK |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Nicoll , G , Holness , M , Troll , V , Donaldson , C H , Holohan , E , Emeleus , C H & Chew , D 2009 , ' Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Mam intrusion breccia ' , Geological Magazine , vol. 146 , no. 3 , pp. 368-381 . https://doi.org/10.1017/S0016756808005864 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1017/S0016756808005864 |
container_title |
Geological Magazine |
container_volume |
146 |
container_issue |
3 |
container_start_page |
368 |
op_container_end_page |
381 |
_version_ |
1766128004771086336 |