from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A soft, earthy, dark-coloured rock or clay derived from the alteration of basalt.
from the GNU version of the Collaborative International Dictionary of English
- n. A soft, earthy, dark-colored rock or clay derived from the alteration of basalt.
from The Century Dictionary and Cyclopedia
- n. A soft homogeneous clay arising from the decomposition of some form of volcanic or eruptive rock. It is of a greenish or brownish color. Compare graywacke.
The house has a dark look, being built of the native whinstone, or grau-wacke, as the Germans call it, relieved by the quoins and projections of the windows and turrets in freestone.
From an intrusive overlying wacke in the neighborhood of Linlithgow I have derived for my collection pieces of carbonized wood in so complete a state of keeping, that under the microscope they exhibit unbroken all the characteristic reticulations of the coniferæ of the Coal Measures.
Hence olivine occurs in basalt, lava, obsidian, artificial scoriae in meteoric stones, in the syenite of Elfdale, and (as hyalosiderite) in the wacke of the Kaiserstuhl.
The basis of these lower lavas is rather wacke than basalt; when it is spongy, it resembles the amygdaloids* of Frankfort-on-the-Main.
This regular disposition of lithoid basaltic lava and feldsparry vitreous lava is analogous to the phenomena of all trappean mountains; it reminds us of those phonolites lying in very ancient basalts, those close mixtures of augite and feldspar which cover the hills of wacke or porous amygdaloids: but why are the porphyritic or feldsparry lavas of the Peak found only on the summit of the volcano?
Mineralization consists of quartz-albite-calcite veining with disseminated pyrite, pyrrhotite and arsenopyrite hosted in pervasively silicified, brecciated siltstone and wacke.
Seriously the most wacke dnews story I haev read in a while!
This occurs in beds from fifty to five thousand feet in width, alternating with grey wacke and grey wacke slate.
Grey wacke decomposes likewise into a sand or gravel: but the cement, consisting of clay and lime, forms a considerable part, and makes a tolerable soil.
Limespar runs in veins and detached masses through the whole of this limestone formation; and both it and the grey wacke slate contain quantities of the cubic pyrites.
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