The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland
The Sgurr of Eigg Pitchstone on the Isle of Eigg, NW Scotland, is a crystal-rich, trachydacitic, partially vitrophyric rock, which has previously been interpreted both as a lava and as a sill. We interpret this rock as a chemically zoned, rheomorphic, lava-like ignimbrite that formed during a sustai...
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ftuglasgow:oai:eprints.gla.ac.uk:79502 2023-05-15T17:34:04+02:00 The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland Brown, D.J. Bell, B.R. 2013 http://eprints.gla.ac.uk/79502/ unknown Geological Society of London Brown, D.J. <http://eprints.gla.ac.uk/view/author/4056.html> and Bell, B.R. <http://eprints.gla.ac.uk/view/author/2673.html> (2013) The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland. Journal of the Geological Society <http://eprints.gla.ac.uk/view/journal_volume/Journal_of_the_Geological_Society.html>, 170(5), pp. 753-767. (doi:10.1144/jgs2012-147 <http://dx.doi.org/10.1144/jgs2012-147>) QE Geology Articles PeerReviewed 2013 ftuglasgow https://doi.org/10.1144/jgs2012-147 2022-06-30T22:09:33Z The Sgurr of Eigg Pitchstone on the Isle of Eigg, NW Scotland, is a crystal-rich, trachydacitic, partially vitrophyric rock, which has previously been interpreted both as a lava and as a sill. We interpret this rock as a chemically zoned, rheomorphic, lava-like ignimbrite that formed during a sustained pyroclastic eruption. The Sgurr of Eigg Pitchstone can be subdivided into discrete emplacement units distinguished by the following features: (1) their present-day weathering characteristics; (2) the orientation, spacing and morphology of the columnar joints; (3) sharp, undulating boundaries with marked topographic breaks. The absence of weathered surfaces, palaeosols, pyroclastic fall deposits or sedimentary rocks at emplacement unit boundaries suggests deposition from a single eruption. The emplacement units, some of which display upper and basal vitrophyres, represent distinct depositional packages that record several rapidly emplaced ignimbrites, which welded, cooled and devitrified as a simple, essentially single, cooling unit, during eruption from a sustained, low pyroclastic column. The Sgurr of Eigg Pitchstone displays a pervasive base-parallel flow banding, which is folded into intrafolial recumbent isoclinal folds. The flow banding and folds indicate that rheomorphism occurred throughout deposition. The Sgurr of Eigg Pitchstone is interpreted as an erosional remnant of an extensive ignimbrite sheet, the first such unit recorded within the North Atlantic Igneous Province. Article in Journal/Newspaper North Atlantic University of Glasgow: Enlighten - Publications Journal of the Geological Society 170 5 753 767 |
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Open Polar |
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University of Glasgow: Enlighten - Publications |
op_collection_id |
ftuglasgow |
language |
unknown |
topic |
QE Geology |
spellingShingle |
QE Geology Brown, D.J. Bell, B.R. The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland |
topic_facet |
QE Geology |
description |
The Sgurr of Eigg Pitchstone on the Isle of Eigg, NW Scotland, is a crystal-rich, trachydacitic, partially vitrophyric rock, which has previously been interpreted both as a lava and as a sill. We interpret this rock as a chemically zoned, rheomorphic, lava-like ignimbrite that formed during a sustained pyroclastic eruption. The Sgurr of Eigg Pitchstone can be subdivided into discrete emplacement units distinguished by the following features: (1) their present-day weathering characteristics; (2) the orientation, spacing and morphology of the columnar joints; (3) sharp, undulating boundaries with marked topographic breaks. The absence of weathered surfaces, palaeosols, pyroclastic fall deposits or sedimentary rocks at emplacement unit boundaries suggests deposition from a single eruption. The emplacement units, some of which display upper and basal vitrophyres, represent distinct depositional packages that record several rapidly emplaced ignimbrites, which welded, cooled and devitrified as a simple, essentially single, cooling unit, during eruption from a sustained, low pyroclastic column. The Sgurr of Eigg Pitchstone displays a pervasive base-parallel flow banding, which is folded into intrafolial recumbent isoclinal folds. The flow banding and folds indicate that rheomorphism occurred throughout deposition. The Sgurr of Eigg Pitchstone is interpreted as an erosional remnant of an extensive ignimbrite sheet, the first such unit recorded within the North Atlantic Igneous Province. |
format |
Article in Journal/Newspaper |
author |
Brown, D.J. Bell, B.R. |
author_facet |
Brown, D.J. Bell, B.R. |
author_sort |
Brown, D.J. |
title |
The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland |
title_short |
The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland |
title_full |
The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland |
title_fullStr |
The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland |
title_full_unstemmed |
The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland |
title_sort |
emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the sgurr of eigg pitchstone, nw scotland |
publisher |
Geological Society of London |
publishDate |
2013 |
url |
http://eprints.gla.ac.uk/79502/ |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Brown, D.J. <http://eprints.gla.ac.uk/view/author/4056.html> and Bell, B.R. <http://eprints.gla.ac.uk/view/author/2673.html> (2013) The emplacement of a large, chemically zoned, rheomorphic, lava-like ignimbrite: the Sgurr of Eigg Pitchstone, NW Scotland. Journal of the Geological Society <http://eprints.gla.ac.uk/view/journal_volume/Journal_of_the_Geological_Society.html>, 170(5), pp. 753-767. (doi:10.1144/jgs2012-147 <http://dx.doi.org/10.1144/jgs2012-147>) |
op_doi |
https://doi.org/10.1144/jgs2012-147 |
container_title |
Journal of the Geological Society |
container_volume |
170 |
container_issue |
5 |
container_start_page |
753 |
op_container_end_page |
767 |
_version_ |
1766132779004723200 |