graywacke


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gray·wacke

 (grā′wăk′, -wăk′ə)
n.
Any of various dark gray sandstones that contain shale.

[Partial translation of German Grauwacke : grau, gray + Wacke, rock (from Middle High German, from Old High German waggo, boulder; see wegh- in Indo-European roots).]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
References in periodicals archive ?
of crushed graywacke hipped to om the It is made rock called aggregate, sh Bahrain fro Quarry.
e of crushed graywacke hipped to m the It is made rock called g aggregate, sh Bahrain fro Quarry.
The main gold vein prospect on the property occurs as low-sulfide, mesothermal quartz veins within Nicola Group siltstone and graywacke. One steeply-dipping vein exposed by a series of short trenches is at least 90 m long, strikes east-northeast, is typically 1.5 m wide and reaches a width of 2.5 m.
The surface of the track is made from Graywacke aggregate, shipped to Abu Dhabi from Bayston Hill quarry in Shropshire, England.
Wacke, Graywacke and Matrix--What Approach to Immature Sandstone Classification?