The Whitsunday Volcanic Province, Central Queensland, Australia: lithological and stratigraphic investigations of a silicic-dominated large igneous province
Contrary to general belief, not all large igneous provinces (LIPs) are characterised by rocks of basaltic composition. Silicic-dominated LIPs, such as the Whitsunday Volcanic Province of NE Australia, are being increasingly recognised in the rock record. These silicic LIPs are consistent in being: (...
Published in: | Journal of Volcanology and Geothermal Research |
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ftunivqespace:oai:espace.library.uq.edu.au:UQ:139302 2023-05-15T13:47:31+02:00 The Whitsunday Volcanic Province, Central Queensland, Australia: lithological and stratigraphic investigations of a silicic-dominated large igneous province Bryan, S. E. Ewart, A. Stephens, C. J. Parianos, J. Downes, P. J. Professor Yoshiaki Ida 2000-01-01 https://espace.library.uq.edu.au/view/UQ:139302 eng eng Elsevier Science doi:10.1016/S0377-0273(00)00157-8 issn:0377-0273 Geosciences Multidisciplinary Early Cretaceous Large Igneous Province Eastern Australia Ignimbrite Volcanic Evolution New-zealand Goboboseb Mountains Etendeka Volcanism West Antarctica Geochronology Complex Namibia Magmatism Gondwana Plateau 260103 Vulcanology C1 780104 Earth sciences Journal Article 2000 ftunivqespace https://doi.org/10.1016/S0377-0273(00)00157-8 2020-12-07T23:30:23Z Contrary to general belief, not all large igneous provinces (LIPs) are characterised by rocks of basaltic composition. Silicic-dominated LIPs, such as the Whitsunday Volcanic Province of NE Australia, are being increasingly recognised in the rock record. These silicic LIPs are consistent in being: (1) volumetrically dominated by ignimbrite; (2) active over prolonged periods (40-50 m.y.), based on available age data; and (3) spatially and temporally associated with plate break-up. This silicic dominated LIP, related to the break-up of eastern continental Gondwana, is also significant for being the source of > 1.4 x 10(6) km(3) of coeval volcanogenic sediment preserved in adjacent sedimentary basins of eastern Australia. The Whitsunday Volcanic Province is volumetrically dominated by medium- to high-grade, dacitic to rhyolitic lithic ignimbrites. Individual ignimbrite units are commonly between 10 and 100 m thick, and the ignimbrite-dominated sequences exceed 1 km in thickness. Coarse lithic lag breccias containing clasts up to 6 m diameter are associated with the ignimbrites in proximal sections. Pyroclastic surge and fallout deposits, subordinate basaltic to rhyolitic lavas, phreatomagmatic deposits, and locally significant thicknesses of coarse-grained volcanogenic conglomerate and sandstone are interbedded with the ignimbrites. The volcanic sequences are intruded by gabbro/dolerite to rhyolite dykes (up to 50 m in width), sills and comagmatic granite. Dyke orientations are primarily from NW to NNE. The volcanic sequences are characterised by the interstratification of proximal/near-vent lithofacies such as rhyolite domes and lavas, and basaltic agglomerate, with medial to distal facies of ignimbrite. The burial of these near-vent lithofacies by ignimbrites, coupled with the paucity of mass wastage products such as debris-flow deposits indicates a low-relief depositional environment. Furthermore, the volcanic succession records a temporal change in: (1) eruptive styles; (2) the nature of source vents; and (3) erupted compositions. An early explosive dacitic pyroclastic phase was succeeded by a later mixed pyroclastic-effusive phase producing an essentially bimodal suite of lavas and rhyolitic ignimbrite. From the nature and distribution of volcanic lithofacies. the volcanic sequences are interpreted to record the evolution of a multiple vent, low-relief volcanic region, dominated by several large caldera centres. (C) 2000 Elsevier Science B.V. All rights reserved. Article in Journal/Newspaper Antarc* Antarctica West Antarctica The University of Queensland: UQ eSpace New Zealand Queensland West Antarctica Journal of Volcanology and Geothermal Research 99 1-4 55 78 |
institution |
Open Polar |
collection |
The University of Queensland: UQ eSpace |
op_collection_id |
ftunivqespace |
language |
English |
topic |
Geosciences Multidisciplinary Early Cretaceous Large Igneous Province Eastern Australia Ignimbrite Volcanic Evolution New-zealand Goboboseb Mountains Etendeka Volcanism West Antarctica Geochronology Complex Namibia Magmatism Gondwana Plateau 260103 Vulcanology C1 780104 Earth sciences |
spellingShingle |
Geosciences Multidisciplinary Early Cretaceous Large Igneous Province Eastern Australia Ignimbrite Volcanic Evolution New-zealand Goboboseb Mountains Etendeka Volcanism West Antarctica Geochronology Complex Namibia Magmatism Gondwana Plateau 260103 Vulcanology C1 780104 Earth sciences Bryan, S. E. Ewart, A. Stephens, C. J. Parianos, J. Downes, P. J. The Whitsunday Volcanic Province, Central Queensland, Australia: lithological and stratigraphic investigations of a silicic-dominated large igneous province |
topic_facet |
Geosciences Multidisciplinary Early Cretaceous Large Igneous Province Eastern Australia Ignimbrite Volcanic Evolution New-zealand Goboboseb Mountains Etendeka Volcanism West Antarctica Geochronology Complex Namibia Magmatism Gondwana Plateau 260103 Vulcanology C1 780104 Earth sciences |
description |
Contrary to general belief, not all large igneous provinces (LIPs) are characterised by rocks of basaltic composition. Silicic-dominated LIPs, such as the Whitsunday Volcanic Province of NE Australia, are being increasingly recognised in the rock record. These silicic LIPs are consistent in being: (1) volumetrically dominated by ignimbrite; (2) active over prolonged periods (40-50 m.y.), based on available age data; and (3) spatially and temporally associated with plate break-up. This silicic dominated LIP, related to the break-up of eastern continental Gondwana, is also significant for being the source of > 1.4 x 10(6) km(3) of coeval volcanogenic sediment preserved in adjacent sedimentary basins of eastern Australia. The Whitsunday Volcanic Province is volumetrically dominated by medium- to high-grade, dacitic to rhyolitic lithic ignimbrites. Individual ignimbrite units are commonly between 10 and 100 m thick, and the ignimbrite-dominated sequences exceed 1 km in thickness. Coarse lithic lag breccias containing clasts up to 6 m diameter are associated with the ignimbrites in proximal sections. Pyroclastic surge and fallout deposits, subordinate basaltic to rhyolitic lavas, phreatomagmatic deposits, and locally significant thicknesses of coarse-grained volcanogenic conglomerate and sandstone are interbedded with the ignimbrites. The volcanic sequences are intruded by gabbro/dolerite to rhyolite dykes (up to 50 m in width), sills and comagmatic granite. Dyke orientations are primarily from NW to NNE. The volcanic sequences are characterised by the interstratification of proximal/near-vent lithofacies such as rhyolite domes and lavas, and basaltic agglomerate, with medial to distal facies of ignimbrite. The burial of these near-vent lithofacies by ignimbrites, coupled with the paucity of mass wastage products such as debris-flow deposits indicates a low-relief depositional environment. Furthermore, the volcanic succession records a temporal change in: (1) eruptive styles; (2) the nature of source vents; and (3) erupted compositions. An early explosive dacitic pyroclastic phase was succeeded by a later mixed pyroclastic-effusive phase producing an essentially bimodal suite of lavas and rhyolitic ignimbrite. From the nature and distribution of volcanic lithofacies. the volcanic sequences are interpreted to record the evolution of a multiple vent, low-relief volcanic region, dominated by several large caldera centres. (C) 2000 Elsevier Science B.V. All rights reserved. |
author2 |
Professor Yoshiaki Ida |
format |
Article in Journal/Newspaper |
author |
Bryan, S. E. Ewart, A. Stephens, C. J. Parianos, J. Downes, P. J. |
author_facet |
Bryan, S. E. Ewart, A. Stephens, C. J. Parianos, J. Downes, P. J. |
author_sort |
Bryan, S. E. |
title |
The Whitsunday Volcanic Province, Central Queensland, Australia: lithological and stratigraphic investigations of a silicic-dominated large igneous province |
title_short |
The Whitsunday Volcanic Province, Central Queensland, Australia: lithological and stratigraphic investigations of a silicic-dominated large igneous province |
title_full |
The Whitsunday Volcanic Province, Central Queensland, Australia: lithological and stratigraphic investigations of a silicic-dominated large igneous province |
title_fullStr |
The Whitsunday Volcanic Province, Central Queensland, Australia: lithological and stratigraphic investigations of a silicic-dominated large igneous province |
title_full_unstemmed |
The Whitsunday Volcanic Province, Central Queensland, Australia: lithological and stratigraphic investigations of a silicic-dominated large igneous province |
title_sort |
whitsunday volcanic province, central queensland, australia: lithological and stratigraphic investigations of a silicic-dominated large igneous province |
publisher |
Elsevier Science |
publishDate |
2000 |
url |
https://espace.library.uq.edu.au/view/UQ:139302 |
geographic |
New Zealand Queensland West Antarctica |
geographic_facet |
New Zealand Queensland West Antarctica |
genre |
Antarc* Antarctica West Antarctica |
genre_facet |
Antarc* Antarctica West Antarctica |
op_relation |
doi:10.1016/S0377-0273(00)00157-8 issn:0377-0273 |
op_doi |
https://doi.org/10.1016/S0377-0273(00)00157-8 |
container_title |
Journal of Volcanology and Geothermal Research |
container_volume |
99 |
container_issue |
1-4 |
container_start_page |
55 |
op_container_end_page |
78 |
_version_ |
1766247261708222464 |