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The emplacement and deformation of high-temperature tuffs: a structural analysis of the Grey’s Landing ignimbrite, Snake River Plain, Idaho

By Graham Douglas Michael Andrews


The Grey’s Landing ignimbrite is an exceptionally well-preserved and well-exposed lava-like ignimbrite in the Snake River Plain volcanic province of southern Idaho, USA. High-grade tuffs are typically intensely welded and rheomorphic, preserving evidence of syn- and post-depositional ductile flow. The Grey’s Landing ignimbrite underwent two distinct phases of rheomorphism: (1) syn-depositional welding and rheomorphism as the deposit aggraded, producing a penetrative, mylonite-like L > S fabric including sheath folds, a strong elongation lineation, and shear-sense indicators;\ud and (2) post-depositional, en masse, gravity-driven flow of parts of the deposit down palaeo-slopes, producing a fold-dominated deformation characterised by large-scale folds of the upper surface of the ignimbrite. Thermal and rheological modelling suggest that the original magma was hot (~ 950 °C), volatile-rich (≤ 5 wt % fluorine), and low viscosity (≥ 106 Pa.s-1). Syn-depositional rheomorphism had a strain rate of ~ 10-5 s-1 and deformed ignimbrite with a viscosity similar to the original magma. Postdepositional rheomorphism was limited to 6 months at the upper surface and ≤ 16 years in the centre of the thickest ignimbrite, at a strain rate of ~ 10-6 s-1

Publisher: University of Leicester
Year: 2006
OAI identifier: oai:lra.le.ac.uk:2381/7933

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  5. (1995). Cooling, degassing, and compaction of rhyolitic ash-fl ow tuffs: a computational model: Bulletin of Volcanology, doi
  6. (1999). Dense welding caused by volatile resorption. J Geol Soc Lon 156:217-225 Sparks RSJ, Wright JV doi
  7. (1992). Distinguishing strongly rheomorphic tuffs from extensive silicic lavas:
  8. (2004). Eruption and emplacement of the Yamakogawa rhyolite in central Kyushu, Japan: A model for emplacement of rhyolitic spatter: Earth Planet Space, doi
  9. (1989). Excursion 4A: Silicic volcanic rocks in the Snake River Plain—Yellowstone Plateau province, doi
  10. (1992). Extended cooling and viscous fl ow of large, hot rhyolite lavas: implications of numerical modelling results: doi
  11. (2002). Extension and subsidence of the Eastern Snake River Plain, Idaho, doi
  12. (2000). Geol Soc Am Abs w/Prog 36:12 Manley CR,
  13. (1997). Giant bed from a sustained catastrophic density current fl owing over topography: Acatlàn ignimbrite, Mexico: Geology, doi
  14. (1984). High-temperature, largevolume, lavalike ash-fl ow tuffs without calderas
  15. (1995). How voluminous rhyolite lavas mimic rheomorphic ignimbrites: eruptive style, emplacement conditions, and formation of tuff-like features: doi
  16. (1983). Ignimbrite types and ignimbrite problems: doi
  17. (2000). Insights into emplacement and fl ow 17 fl d006-15
  18. (1992). Insights into emplacement and fl ow 7 fl d006-15 page 7 of 18 Figure 6. Simplifi ed geologic map of the Yellowstone–Snake River Plain volcanic province. Modifi ed from Pierce and Morgan
  19. (1981). Italienische Vulkan-Gebeite III: Lipari, Vulcano, Stromboli, Tyrrenisches Meer: Sammlung Geologische Fuhrer,
  20. (1967). Laminar viscous fl owage structures in ash-fl ow tuffs from Gran Canaria, Canary Islands: doi
  21. (2002). Late Miocene, Pliocene, and Pleistocene geology of southwestern Idaho with emphasis on basalts in the Bruneau-Jarbidge, Twin Falls, and Western Snake River Plain regions,
  22. (1966). Mechanism of deposition from pyroclastic fl ows: doi
  23. (1987). Physical features of rhyolite lava fl ows in the Snake River Plain volcanic province, southwestern Idaho, doi
  24. (1996). Physical volcanology of a voluminous rhyolite lava fl ow: the Badlands lava, Owyhee plateau, doi
  25. (1996). Preliminary volcanological constraints for sources of high-grade, rheomorphic ignimbrites of the Cassia Mountains, Idaho: Implications for the evolution of the Twin Falls Volcanic Center: Northwest Geology,
  26. (1979). Primary and secondary fl ow structures in ash-fl ow tuffs of the Gribbles Run paleovalley, central Colorado, doi
  27. (2002). Pyroclastic density currents and the sedimentation of ignimbrites: London, doi
  28. (1984). Pyroclastic rocks and calderas associated with strongly peralkaline volcanic rocks: doi
  29. (1997). Rheology, relaxation and the glass transition in silicate melts: doi
  30. (1981). Rheomorphism of welded tuffs: doi
  31. (1982). Rhyolite lava fl ows in the Bruneau-Jarbidge Eruptive Center, southwestern Idaho, doi
  32. (2004). Sheathfolds in rheomorphic ignimbrites: doi
  33. (1992). The Bad Step Tuff: a lava-like ignimbrite in a calc-alkaline piecemeal caldera, English Lake District: Bulletin of Volcanology,
  34. (1982). The Cougar Point Tuff, southwestern Idaho,
  35. (2002). The emplacement history of a remarkable heterogeneous, chemically zoned, rheomorphic and locally lava-like ignimbrite: doi
  36. (2002). The emplacement history of a remarkable heterogeneous, chemically zoned, rheomorphic and locally lava-like ignimbrite: ‘TL’ doi
  37. (1998). The formation of high-grade ignimbrites; 1: Experiments on high- and low-concentration transport systems containing sticky particles: doi
  38. (2001). The Quaternary and Pliocene Yellowstone Plateau volcanic fi eld of Wyoming,
  39. (1992). The track of the Yellowstone hotspot: volcanism, faulting, and uplift, doi
  40. (1962). Upper Cenozoic stratigraphy of the western Snake River Plain, Idaho: doi
  41. (1990). with contributions by

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