pyroclast


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Related to pyroclast: batholith, tephra, Pyroclastic flow

pyroclast

[′pī·rə‚klast]
(geology)
An individual pyroclastic fragment or clast.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The breccia is composed by a grey-to-white matrix (<2 mm in size) constituted by small grains of host sedimentary rocks and volcanic rocks (from lava fragments and lapilli-size pyroclasts to coarse ash) (Fig.
7) associated with calderas located at the centers of very low shieldlike features, and half produce umbrella-shaped eruption clouds into which gases and small pyroclasts are ejected at speeds of up to 1000 m/s to reach heights up to 300 km (Fig.
The rock units in the area mainly include Eocene volcanic rocks (lava flows and pyroclasts belonging to the Karaj formation) and Oligocene granitoid intrusive bodies (figure 2).
Sizes and Shapes of 10-Ma Distal Fall Pyroclasts in the Ogallala Group, Nebraska.
Starting in 1975, he was also a major contributor to this journal in a column called Pyroclasts, which put forward, "news and comment on some of the peripheral matters of interest to Canadian geoscientists, for example, politics and politicians, sex, relations with sister societies, assorted scuttle-butt and rife humour" (Neale 1975).
The topsoil, formed from salic pyroclasts, is covered by a layer of approximately 15 cm (5.9 in) of pumice fragments between 5 to 20 mm (0.2 to 0.8 in) in size.
Magmatic Processes in Forming Maars and Associated Pyroclasts: The Calatrava--Spain--Case History.
The bentonite at 666.0 m contains abundantly grains larger than 100 um, while that at 660.0 m contains mostly pyroclasts within the range of 40-100 um and only a small portion of larger grains.
Pyroclasts are produced by the explosive fragmentation of magma; this fragmentation occurs in the magma conduit or at high levels in the magma chamber (Fig.