tuffaceous


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Related to tuffaceous: Volcanic Tuff

tuffaceous

[tə′fā·shəs]
(geology)
Pertaining to sediments which contain up to 50% tuff.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
These rocks contained dolomite, clay minerals, quartz, tuffaceous matrix, tuff debris, calcite, ferruginous debris, siliceous debris and anorthose.
(1980) recognized a unit of dacitic tufts and breccias (their 'Bluff tuff-breccia') overlain by andesitic sedimentary and tuffaceous rocks (the term 'possibly' is used here because descriptions of rock units by different authors are comparable only in a general sense, not in detail).
derived from tuffaceous caldera-lake deposits that belong to the middle
The petrographic characters clearly indicate that this horizon represents glassy welded tuffaceous material, perhaps the consolidated ash layer directly resting on the Lameta limestones.
The Nelson soil, a Motupiko silt loam, is a weathered fluvial recent soil derived from greywacke, whereas the Southland soil, a Waikiwi silt loam, is a deeper soil derived from loess from tuffaceous greywacke and schist.
The occurrence of these minerals on meionite in soil may represent a new genetic mode, as they have previously been reported only from basalt and tuffaceous rhyolite beds (Gottardi et al., 1985).
The dominant raw material throughout the deposit was called 'chert' by McCarthy, a nomenclature we continue even though it is likely to be tuffaceous mudstone.
Geologically, the mine area is quaternary alluvium, the overburden consisting predominantly of arkosic sand, arkosic sandstone interbedded with tuffaceous clays, and caliche with cobble and boulder lenses.
Silica may have been derived from bentonite, tuffaceous rock, and silicate minerals.
Unlike the ash that covered Pompeii, however, what fell on Herculaneum formed a compact mass of hard, tuffaceous matter 60 feet deep that preserved the town embedded within almost as perfectly as amber preserves an insect.