Volcanic Tuff


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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Tuff, Volcanic

 

a dense volcanic rock formed by the cementation of ash, scoria, lapilli, and other éjecta from an erupting volcano. Tuffs consist of fragments of volcanic glass, pumice, and other substances; tuffs composed of whole crystals or crystal fragments are also encountered.

Tuffs are classified according to composition, nature, and fragment sizes. In terms of composition, we distinguish among rhyo-litic, dacitic, andesitic, basaltic, and other tuffs. The color of tuffs varies; Artik tuff is violet-pink, and Ani tuff is orange or yellow (both types are found in the Armenian SSR). Tuffs are formed either by direct deposition from the air during a volcanic eruption or as a result of the transport of tuffaceous material by water or wind.

Tuff is a valuable building material of excellent ornamental quality. It is used, for example, as a filler in light concrete or as a wall material. In the USSR the main tuff deposits are in Armenia. In other countries the most important deposits are near Rome and Naples in Italy and in Iceland.

V. P. PETROV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

tuff, volcanic tuff

A low-density, high-porosity rock; composed of volcanic particles, ranging from ash size to small pebble size, which are compacted or cemented together; sometimes used as building stone or as a thermal insulation material.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
In this paper, raw materials of the Middle East countries (quartz sand, fine grained screenings of concrete breakage, volcanic tuff) were used as a mineral additive in the composite gypsum binder (CGB).
Volcanic tuffs have three different groups as follows: Gulludag Tuff, Melendiz Tuff and Alacasar Tuff.
According to Gottardi (1989), these deposits form as a result of the slow percolation of meteoric water through volcanic tuff beds, becoming more alkaline and saline with depth, thus raising its pH.
Quarried slabs of red or yellow volcanic tuff (ke'etu) are widely associated with both religious and residential sites.
It may be that these cherts are the result of leaching on an erosion surface on top of a pile of volcanic tuff deposits.
Quartz-rich volcanic tuffs, that contain anomalous amounts of lithium, occur within and adjacent to the valley.
The terrigenous rocks usually alternate with acidic volcanic tuffs in the upper parts of the terrigenous group, where their main component is the volcanic glass.
The orebody is hosted in strongly layered volcanic tuffs and rhyolites which occur beneath the gravels.
The soil is volcanic - 5 to 60 % fractured basalt shale and volcanic tuffs. Damskey combines the differences found in each vineyard to create blends of what he terms layered complexity.