Formation of a spatter-rich pyroclastic density current deposit in a Neogene sequence of trachytic-mafic igneous rocks at Mason Spur, Erebus volcanic province, Antarctica
Erosion has revealed a remarkable section through the heart of a volcanic island, Mason Spur, in the southwestern Ross Sea, Antarctica, including an unusually well-exposed section of caldera fill. The near-continuous exposure, 10 km laterally and > 1 km vertically, cuts through Cenozoic alkalic v...
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ftleicesterunfig:oai:figshare.com:article/10214825 2023-05-15T13:49:19+02:00 Formation of a spatter-rich pyroclastic density current deposit in a Neogene sequence of trachytic-mafic igneous rocks at Mason Spur, Erebus volcanic province, Antarctica A. P Martin John. L Smellie A. F Cooper D. B Townsend 2017-12-29T00:00:00Z https://figshare.com/articles/journal_contribution/Formation_of_a_spatter-rich_pyroclastic_density_current_deposit_in_a_Neogene_sequence_of_trachytic-mafic_igneous_rocks_at_Mason_Spur_Erebus_volcanic_province_Antarctica/10214825 unknown 2381/41456 https://figshare.com/articles/journal_contribution/Formation_of_a_spatter-rich_pyroclastic_density_current_deposit_in_a_Neogene_sequence_of_trachytic-mafic_igneous_rocks_at_Mason_Spur_Erebus_volcanic_province_Antarctica/10214825 All Rights Reserved Uncategorized Science & Technology Physical Sciences Geosciences Multidisciplinary Geology Explosive volcanism Ignimbrite Lapilli tuff McMurdo Volcanic Group Pyroclastic density current Trachytic spatter MORNING ERUPTIVE CENTER SOUTHERN VICTORIA LAND LITHOSPHERIC MANTLE CALDERA COLLAPSE FRAGMENTATION EMPLACEMENT DYNAMICS FLOW PETROGENESIS Text Journal contribution 2017 ftleicesterunfig 2021-11-11T19:31:37Z Erosion has revealed a remarkable section through the heart of a volcanic island, Mason Spur, in the southwestern Ross Sea, Antarctica, including an unusually well-exposed section of caldera fill. The near-continuous exposure, 10 km laterally and > 1 km vertically, cuts through Cenozoic alkalic volcanic rocks of the Erebus volcanic province (McMurdo Volcanic Group) and permits the study of an ancient volcanic succession that is rarely available due to subsequent burial or erosion. The caldera filling sequence includes an unusual trachytic spatter-rich lapilli tuff (ignimbrite) facies that is particularly striking because of the presence of abundant black fluidal, dense juvenile spatter clasts of trachytic obsidian up to 2 m long supported in a pale cream-coloured pumiceous lapilli tuff matrix. Field mapping indicates that the deposit is an ignimbrite and, together with petrological considerations, it is suggested that mixing of dense spatter and pumiceous lapilli tuff in the investigated deposit occurred during emplacement, not necessarily in the same vent, with the mixed fragmental material emplaced as a pyroclastic density current. Liquid water was not initially present but a steam phase was probably generated during transport and may represent water ingested during passage of the current as it passed over either wet ground, stream, shallow lake or (possibly) snow. Well-exposed caldera interiors are uncommon and that at Mason Spur is helping understand eruption dynamics associated with a complex large island volcano. The results of our study should help to elucidate interpretations of other, less well exposed, pyroclastic density current deposits elsewhere in Antarctica and globally. Other Non-Article Part of Journal/Newspaper Antarc* Antarctica Ross Sea Victoria Land University of Leicester: Figshare Mason Spur ENVELOPE(164.417,164.417,-78.550,-78.550) Ross Sea Victoria Land |
institution |
Open Polar |
collection |
University of Leicester: Figshare |
op_collection_id |
ftleicesterunfig |
language |
unknown |
topic |
Uncategorized Science & Technology Physical Sciences Geosciences Multidisciplinary Geology Explosive volcanism Ignimbrite Lapilli tuff McMurdo Volcanic Group Pyroclastic density current Trachytic spatter MORNING ERUPTIVE CENTER SOUTHERN VICTORIA LAND LITHOSPHERIC MANTLE CALDERA COLLAPSE FRAGMENTATION EMPLACEMENT DYNAMICS FLOW PETROGENESIS |
spellingShingle |
Uncategorized Science & Technology Physical Sciences Geosciences Multidisciplinary Geology Explosive volcanism Ignimbrite Lapilli tuff McMurdo Volcanic Group Pyroclastic density current Trachytic spatter MORNING ERUPTIVE CENTER SOUTHERN VICTORIA LAND LITHOSPHERIC MANTLE CALDERA COLLAPSE FRAGMENTATION EMPLACEMENT DYNAMICS FLOW PETROGENESIS A. P Martin John. L Smellie A. F Cooper D. B Townsend Formation of a spatter-rich pyroclastic density current deposit in a Neogene sequence of trachytic-mafic igneous rocks at Mason Spur, Erebus volcanic province, Antarctica |
topic_facet |
Uncategorized Science & Technology Physical Sciences Geosciences Multidisciplinary Geology Explosive volcanism Ignimbrite Lapilli tuff McMurdo Volcanic Group Pyroclastic density current Trachytic spatter MORNING ERUPTIVE CENTER SOUTHERN VICTORIA LAND LITHOSPHERIC MANTLE CALDERA COLLAPSE FRAGMENTATION EMPLACEMENT DYNAMICS FLOW PETROGENESIS |
description |
Erosion has revealed a remarkable section through the heart of a volcanic island, Mason Spur, in the southwestern Ross Sea, Antarctica, including an unusually well-exposed section of caldera fill. The near-continuous exposure, 10 km laterally and > 1 km vertically, cuts through Cenozoic alkalic volcanic rocks of the Erebus volcanic province (McMurdo Volcanic Group) and permits the study of an ancient volcanic succession that is rarely available due to subsequent burial or erosion. The caldera filling sequence includes an unusual trachytic spatter-rich lapilli tuff (ignimbrite) facies that is particularly striking because of the presence of abundant black fluidal, dense juvenile spatter clasts of trachytic obsidian up to 2 m long supported in a pale cream-coloured pumiceous lapilli tuff matrix. Field mapping indicates that the deposit is an ignimbrite and, together with petrological considerations, it is suggested that mixing of dense spatter and pumiceous lapilli tuff in the investigated deposit occurred during emplacement, not necessarily in the same vent, with the mixed fragmental material emplaced as a pyroclastic density current. Liquid water was not initially present but a steam phase was probably generated during transport and may represent water ingested during passage of the current as it passed over either wet ground, stream, shallow lake or (possibly) snow. Well-exposed caldera interiors are uncommon and that at Mason Spur is helping understand eruption dynamics associated with a complex large island volcano. The results of our study should help to elucidate interpretations of other, less well exposed, pyroclastic density current deposits elsewhere in Antarctica and globally. |
format |
Other Non-Article Part of Journal/Newspaper |
author |
A. P Martin John. L Smellie A. F Cooper D. B Townsend |
author_facet |
A. P Martin John. L Smellie A. F Cooper D. B Townsend |
author_sort |
A. P Martin |
title |
Formation of a spatter-rich pyroclastic density current deposit in a Neogene sequence of trachytic-mafic igneous rocks at Mason Spur, Erebus volcanic province, Antarctica |
title_short |
Formation of a spatter-rich pyroclastic density current deposit in a Neogene sequence of trachytic-mafic igneous rocks at Mason Spur, Erebus volcanic province, Antarctica |
title_full |
Formation of a spatter-rich pyroclastic density current deposit in a Neogene sequence of trachytic-mafic igneous rocks at Mason Spur, Erebus volcanic province, Antarctica |
title_fullStr |
Formation of a spatter-rich pyroclastic density current deposit in a Neogene sequence of trachytic-mafic igneous rocks at Mason Spur, Erebus volcanic province, Antarctica |
title_full_unstemmed |
Formation of a spatter-rich pyroclastic density current deposit in a Neogene sequence of trachytic-mafic igneous rocks at Mason Spur, Erebus volcanic province, Antarctica |
title_sort |
formation of a spatter-rich pyroclastic density current deposit in a neogene sequence of trachytic-mafic igneous rocks at mason spur, erebus volcanic province, antarctica |
publishDate |
2017 |
url |
https://figshare.com/articles/journal_contribution/Formation_of_a_spatter-rich_pyroclastic_density_current_deposit_in_a_Neogene_sequence_of_trachytic-mafic_igneous_rocks_at_Mason_Spur_Erebus_volcanic_province_Antarctica/10214825 |
long_lat |
ENVELOPE(164.417,164.417,-78.550,-78.550) |
geographic |
Mason Spur Ross Sea Victoria Land |
geographic_facet |
Mason Spur Ross Sea Victoria Land |
genre |
Antarc* Antarctica Ross Sea Victoria Land |
genre_facet |
Antarc* Antarctica Ross Sea Victoria Land |
op_relation |
2381/41456 https://figshare.com/articles/journal_contribution/Formation_of_a_spatter-rich_pyroclastic_density_current_deposit_in_a_Neogene_sequence_of_trachytic-mafic_igneous_rocks_at_Mason_Spur_Erebus_volcanic_province_Antarctica/10214825 |
op_rights |
All Rights Reserved |
_version_ |
1766251169900920832 |