Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm 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 |
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Cambridge University Press
2009
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Online Access: | http://eprints.esc.cam.ac.uk/3900/ http://eprints.esc.cam.ac.uk/3900/1/early_mafic_magmatism_and_crustal_anatexis_on_the_isle_of_rum_evidence_from_the_am_mam_intrusion_breccia.pdf https://doi.org/10.1017/S0016756808005864 |
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ftucambridgeesc:oai:eprints.esc.cam.ac.uk:3900 2023-05-15T17:34:11+02:00 Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm intrusion breccia NICOLL, GRAEME R. Holness, Marian B. TROLL, VALENTIN R. DONALDSON, COLIN H. HOLOHAN, EOGHAN P. EMELEUS, C. HENRY CHEW, DAVID 2009 text http://eprints.esc.cam.ac.uk/3900/ http://eprints.esc.cam.ac.uk/3900/1/early_mafic_magmatism_and_crustal_anatexis_on_the_isle_of_rum_evidence_from_the_am_mam_intrusion_breccia.pdf https://doi.org/10.1017/S0016756808005864 en eng Cambridge University Press http://eprints.esc.cam.ac.uk/3900/1/early_mafic_magmatism_and_crustal_anatexis_on_the_isle_of_rum_evidence_from_the_am_mam_intrusion_breccia.pdf NICOLL, GRAEME R. and Holness, Marian B. and TROLL, VALENTIN R. and DONALDSON, COLIN H. and HOLOHAN, EOGHAN P. and EMELEUS, C. HENRY and CHEW, DAVID (2009) Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm intrusion breccia. Geological Magazine, 146 (03). p. 368. ISSN 0016-7568, ESSN: 1469-5081 DOI https://doi.org/10.1017/S0016756808005864 <https://doi.org/10.1017/S0016756808005864> 05 - Petrology - Igneous Metamorphic and Volcanic Studies Article PeerReviewed 2009 ftucambridgeesc https://doi.org/10.1017/S0016756808005864 2020-08-27T18:09:49Z 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 Cambridge, Department of Earth Sciences: ESC Publications Geological Magazine 146 3 368 381 |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
05 - Petrology - Igneous Metamorphic and Volcanic Studies |
spellingShingle |
05 - Petrology - Igneous Metamorphic and Volcanic Studies NICOLL, GRAEME R. Holness, Marian B. TROLL, VALENTIN R. DONALDSON, COLIN H. HOLOHAN, EOGHAN P. EMELEUS, C. HENRY CHEW, DAVID Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm intrusion breccia |
topic_facet |
05 - Petrology - Igneous Metamorphic and Volcanic Studies |
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 R. Holness, Marian B. TROLL, VALENTIN R. DONALDSON, COLIN H. HOLOHAN, EOGHAN P. EMELEUS, C. HENRY CHEW, DAVID |
author_facet |
NICOLL, GRAEME R. Holness, Marian B. TROLL, VALENTIN R. DONALDSON, COLIN H. HOLOHAN, EOGHAN P. EMELEUS, C. HENRY CHEW, DAVID |
author_sort |
NICOLL, GRAEME R. |
title |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm intrusion breccia |
title_short |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm intrusion breccia |
title_full |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm intrusion breccia |
title_fullStr |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm intrusion breccia |
title_full_unstemmed |
Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm intrusion breccia |
title_sort |
early mafic magmatism and crustal anatexis on the isle of rum: evidence from the am màm intrusion breccia |
publisher |
Cambridge University Press |
publishDate |
2009 |
url |
http://eprints.esc.cam.ac.uk/3900/ http://eprints.esc.cam.ac.uk/3900/1/early_mafic_magmatism_and_crustal_anatexis_on_the_isle_of_rum_evidence_from_the_am_mam_intrusion_breccia.pdf https://doi.org/10.1017/S0016756808005864 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://eprints.esc.cam.ac.uk/3900/1/early_mafic_magmatism_and_crustal_anatexis_on_the_isle_of_rum_evidence_from_the_am_mam_intrusion_breccia.pdf NICOLL, GRAEME R. and Holness, Marian B. and TROLL, VALENTIN R. and DONALDSON, COLIN H. and HOLOHAN, EOGHAN P. and EMELEUS, C. HENRY and CHEW, DAVID (2009) Early mafic magmatism and crustal anatexis on the Isle of Rum: evidence from the Am Màm intrusion breccia. Geological Magazine, 146 (03). p. 368. ISSN 0016-7568, ESSN: 1469-5081 DOI https://doi.org/10.1017/S0016756808005864 <https://doi.org/10.1017/S0016756808005864> |
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 |
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1766132939916050432 |