rock flour


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Related to rock flour: Glacial flour

rock flour

[′räk ‚flau̇·ər]
(geology)
A fine, chemically unweathered powder of rock-forming minerals produced by pulverization of rock fragments during natural transport or crushing. Also known as glacial flour.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

rock flour

A very finely powdered rock material; Also see silt.

silt, inorganic silt, rock flour

A granular material that is nonplastic or very slightly plastic and exhibits little or no strength when air-dried; usually has a grain size between 0.002 mm and 0.05 mm in diameter.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
That must be of concern because it is thanks to glaciers and material called rock flour, which scatters blue-green rays of light, that we have the dazzling turquoise water of Lake Peyto and its more famous sister, Lake Louise.
As they grind their way along the stony terrain, they produce prodigious amounts of rock flour. Overly dry soil is yet another large source of mineral dust.
In fjords fed by glaciers, for example, surface waters are often milky white - a result of the finely divided "rock flour" caused by abrasion in glaciers.
Krummholz, nunatak, and rock flour are terms that come to life when you hike to a subalpine island of dwarf vegetation (a krummholz), gaze at an isolated outcrop unscathed by a glacier's advance (a nunatak), or dabble your toes in an icy lake colored opaque turquoise by fine glacial silt (rock flour).