Acidic Rock


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Related to Acidic Rock: Acid rock drainage

acidic rock

[ə′sid·ik ′räk]
(petrology)
Igneous rock containing more than 66% SiO2, making it silicic.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Acidic Rock

 

magmatic rocks oversaturated in silica (65–70 percent)—that is, containing a surplus of silica which is precipitated in the form of quartz (granite, diorite) or remains dissolved in the amorphous ground mass, or volcanic glass (obsidian, pitchstone).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Shaded rock ledges and boulders, frequently on limestone though occasionally on acidic rocks; Interior Low Plateau, Cumberland Plateau, Ridge and Valley; occasional; [rarely Coastal Plain].
It grows as saxi-terricolous in hollows or slight depressions of acidic rocks, in open sites exposed to wind, sun, rain or snow, with Polytrichum juniperinum Hedw., Tortula Hedw.