Glacial Clast

  • John G. Van Hoesen
Living reference work entry
DOI: https://doi.org/10.1007/978-1-4614-9213-9_182-1

Definition

A pebble to boulder-sized particle transported, modified, and deposited by glacial ice.

Synonyms

Description

Glacial clasts are typically subangular to subrounded, exhibit asymmetrical wear patterns, and often have characteristic polished and faceted faces with abundant striae oriented parallel to the long axis of the clast (Benn and Evans 2010).

Subtypes

Subglacial, englacial.

Morphometry

Clasts can range from pebble (4–8 mm) to boulder (>256 mm) size and can be of varying lithologies. They can exhibit a variety of shapes but are characteristically subangular to subrounded, and clasts exhibiting bullet, pentagonal, and/or stoss and lee forms are considered especially diagnostic (Boulton 1978; Sharp 1982; Krüger 1984; Eyles 1993; Benn and Evans 2010). Clast shape and roundness can be visualized using RA-C 40 plots developed by Benn and Ballantyne ( 1994), systematized using TRI-PLOT by Graham and Midgley ( 2000) and used by Atkins ( 2003) to...

Keywords

Glacial Deposit Glacial Origin Fluvial Transport Chatter Mark Glaciofluvial Deposit 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Department of Environmental StudiesGreen Mountain CollegePoultneyUSA