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A submarine welded ignimbrite - crystal-rich sandstone facies association in the Cambrian Tyndall Group, western Tasmania, Australia
Citation
White, MJ and McPhie, J, A submarine welded ignimbrite - crystal-rich sandstone facies association in the Cambrian Tyndall Group, western Tasmania, Australia, Journal of Volcanology and Geothermal Research, 76, (3-4) pp. 277-295. ISSN 0377-0273 (1997) [Refereed Article]
DOI: doi:10.1016/S0377-0273(96)00105-9
Abstract
Three occurrences of rhyolitic welded ignimbrite are intercalated within a submarine, below-storm-wave-base sedimentary succession in the Cambrian Tyndall Group, Mount Read Volcanics, western Tasmania. These occurrences are closely associated with very thick crystal-rich sandstone facies that is present at this stratigraphic level throughout the Tyndall Group. This facies is interpreted to comprise deposits from syn-eruptive, crystal-rich, submarine sediment gravity flows that were generated by interaction of subaerial pyroclastic flows with seawater. Removal of fine ash and pumice from the submarine flows by hydraulic sorting and flotation resulted in marked crystal enrichment in the deposits. Rapid, essentially syn-eruptive aggradation of crystal-rich sand led to temporary shoaling so that in some cases, subsequent pyroclastic flows deposited welded ignimbrite in shallow marine or possibly subaerial settings (e.g., Zig Zag Hill welded ignimbrite). Breccia units composed of welded ignimbrite clasts and crystal-rich matrix (e.g., Comstock and Anthony Road ignimbrite breccias) imply that some welded ignimbrite was submerged, providing clasts to syn-eruptive, submarine, crystal-rich sediment gravity flows. One example of welded ignimbrite (Cradle Mountain Link Road) may have been deposited in an entirely below-storm-wave-base environment. The distinctive facies association of welded ignimbrite, crystal-rich sandstone and ignimbrite-clast breccia in the Tyndall Group exemplifies the submarine record of a major rhyolitic explosive eruption in the source volcanic terrane.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Research Division: | Earth Sciences |
| Research Group: | Geology |
| Research Field: | Volcanology |
| Objective Division: | Expanding Knowledge |
| Objective Group: | Expanding Knowledge |
| Objective Field: | Expanding Knowledge in the Earth Sciences |
| UTAS Author: | White, MJ (Mr Matthew White) |
| UTAS Author: | McPhie, J (Professor Jocelyn McPhie) |
| ID Code: | 12130 |
| Year Published: | 1997 |
| Web of Science® Times Cited: | 19 |
| Deposited By: | Earth Sciences |
| Deposited On: | 1997-08-01 |
| Last Modified: | 2011-08-15 |
| Downloads: | 0 |
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