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A volcanic rock formed by the deposition and consolidation of ash flows and nuées ardentes.

[Latin ignis, fire + imber, imbr-, rain + -ite.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Geological Science) a rock formed by the deposition at high temperature and the consolidation of a nuée ardente or other type of ash flow, being a complicated mixture of volcanic materials welded together by heat, hot gases, and pressure. Also called: welded tuft See tuft
[C20: from Latin ign(is) fire + imbr(is), imber shower of rain + -ite1]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
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Binal, "Prediction of mechanical properties of non-welded and moderately welded ignimbrite using physical properties, ultrasonic pulse velocity, and point load index tests," Quarterly Journal of Engineering Geology and Hydrogeology, vol.
This section ends with a massive ignimbrite section of variable thickness that is mapped as a non-formal unit (Butalon ignimbrite) because of its important surface development crowning the main hills in the region (Fig.
All three chronosequences were on the Taupo Pumice soil (Immature Orthic Pumice Soil; Hewitt 1998), formed on the non-welded Taupo ignimbrite (of rhyolitic composition) deposited as a pyroclastic flow around AD 232 (Hogg et al.
(2004) used an airborne laser scanner to survey an area of the 1998 Fukushima disaster, where more than 1,000 shallow landslides occurred on slopes of vapor-phase crystallized ignimbrite overlain by permeable pyroclastics.
The AD 186 Taupo eruption, when 60 [km.sup.3] of rhyolitic pumice and ignimbrite were discharged from a vent located in present-day Lake Taupo, provided the parent material of most soils in the catchment.
Abstract: The dry ecosystems in the ignimbrite meseta of Guanacaste, northwest Costa Rica is mapped.
In the igneous sector, steeply foliated, crystalpoor ignimbrite is intruded by a dome of aphanophyric (roof facies?) rhyolite.
Overburden consists mainly of recent volcanic ignimbrite: hard, competent rocks which should allow steep pit slopes, although between them and the ore there is a layer of palaeo gravels which would call for a wide safety bench in the mine.
2001; Bennett, 2009; Olguin-Villa, 2010; Olguin-Villa et al, 2010), and in the state of Sonora where it is described as peralkaline ignimbrite (Vidal Solano et al, 2005, 2007, 2008a; Barrera-Guerrero and Vidal-Solano, 2010; Gomez-Valencia and Vidal-Solano, 2010).
Schaefer (1995) established a main age for the Rio Claro ignimbrite (formed about 100 ka ago) that defined the limit between the Older and Present Ruiz.
The ancient eruption would have been accompanied by a steady rain of volcanic ash and superheated rocks, along with earthquakes and fast-flowing rivers of lava and hot mud, or ignimbrite.