clast


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clast

[klast]
(geology)
An individual grain, fragment, or constituent of detrital sediment or sedimentary rock produced by physical breakdown of a larger mass.
References in periodicals archive ?
The only occurrence of carbonate rocks is as fossiliferous clasts in breccias near the base of this formation.
CLAST will seek grants to develop libraries of classroom probeware kits, each focusing on a particular set of science learning goals, which participating teachers would be able to check out for extended use.
5-10 cm wide dike is composed of sandy material consisting of abundant clasts of sandstone, siltstone, and claystone, resembling the rocks of the Gauj a Formation.
In both cases it is a highly angular unsorted oligomictic chlorite phyllite breccia containing fractured and partly broken clasts and likely tectonic in origin (Fig 3b).
Clasts are spherical, which may explain the rarity of imbrication.
The absence of any voids not filled by palygorskite, and the orientation of the palygorskite domains parallel to clast faces also support this theory.
These studies consisted of (1) 100-clast counts of the entire 3-15 cm clast range, generally from several adjacent beds in a single exposure, (2) description of the coarser population of the site, and (3) thin section study of a gritty bed from each site to verify clast identification, quantify this finer population, and examine details of clast petrology.
This relationship suggests that sediment transport was to the southeast, in accord with clast imbrication in adjacent conglomerate units which show transport in the same direction.
At ATM, a comparison of clast sizes and artefact sizes indicates that most tools [is greater than] 80 mm and all tools [is greater than] 160 mm have undergone preliminary off-site trimming and that raw material clasts were brought from elsewhere.
We defined as features - and plotted - any concentration of clasts with at least three contiguous elements, with contiguity established when the distance between clasts was lower than the maximum length of each clast.