Journal Title
Title of Journal: Bull Volcanol
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Abbravation: Bulletin of Volcanology
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Publisher
Springer-Verlag
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Authors: M J Branney T L Barry M Godchaux
Publish Date: 2004/02/18
Volume: 66, Issue: 6, Pages: 485-491
Abstract
Structural reappraisal of several classic rheomorphic ignimbrites in Colorado Idaho the Canary Islands and Italy has for the first time revealed abundant oblique folds curvilinear folds and sheathfolds which formed during emplacement Like their equivalents in tectonic shearzones the sheathfold axes lie subparallel to a pervasive elongation lineation and appear as eye structures on rock surfaces normal to the transport direction With the recognition of sheathfolds ignimbrites previously inferred to have undergone complex rheomorphic deformation histories are reinterpreted as recording a single progressive deformation event In some examples the trends of sheathfolds and related lineations change with height through a single ignimbrite suggesting that rheomorphism did not affect the entire thickness of ignimbrite synchronously Instead we infer that in these ignimbrites a thin ductile shearzone rose gradually through the aggrading agglutinating mass whilst the flow direction varied with time This suggests that in some cases both welding and rheomorphism can be extremely rapid with ductile strain rates significantly exceeding rates of ignimbrite aggradation
Keywords:
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- Seismic characterisation of lahars at Volcán de Colima, Mexico
- Observations of volcanic tremor during the January–February 2005 eruption of Mt. Veniaminof, Alaska
- Evolution of the late Pleistocene Mojanda–Fuya Fuya volcanic complex (Ecuador), by progressive adakitic involvement in mantle magma sources
- Evolution of the late Pleistocene Mojanda–Fuya Fuya volcanic complex (Ecuador), by progressive adakitic involvement in mantle magma sources
- The November 2002 eruption of Piton de la Fournaise, Réunion: tracking the pre-eruptive thermal evolution of magma using melt inclusions
- The Cenozoic volcanic province of Tibesti (Sahara of Chad): major units, chronology, and structural features
- A melt viscosity scale for preeruptive magmas
- The ~AD1315 Tarawera and Waiotapu eruptions, New Zealand: contemporaneous rhyolite and hydrothermal eruptions driven by an arrested basalt dike system?
- Development of an automatic volcanic ash sampling apparatus for active volcanoes
- Geochemistry and magmatic properties of eruption episodes from Haroharo linear vent zone, Okataina Volcanic Centre, New Zealand during the last 10 kyr
- Geochemistry and magmatic properties of eruption episodes from Haroharo linear vent zone, Okataina Volcanic Centre, New Zealand during the last 10 kyr
- Finding of an historical document describing an eruption in the NW flank of Etna in July 1643 AD: timing, location and volcanic products
- Relationship between the flank sliding of the South East Crater (Mt. Etna, Italy) and the paroxysmal event of November 16, 2006
- Fault textures in volcanic conduits: evidence for seismic trigger mechanisms during silicic eruptions
- Role of magma mixing in the petrogenesis of tephra erupted during the 1990–98 explosive activity of Nevado Sabancaya, southern Peru
- Fragmentation in kimberlite: products and intensity of explosive eruption
- Geological constraints on the emplacement mechanism of the Parinacota debris avalanche, northern Chile
- Diverse mid-Miocene silicic volcanism associated with the Yellowstone–Newberry thermal anomaly
- Smithsonian Institution’s Global Volcanism Network
- Geometry and growth of sill complexes: insights using 3D seismic from the North Rockall Trough
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