shale

(redirected from shaley)
Also found in: Dictionary, Thesaurus.
Related to shaley: Shaly

shale,

sedimentary rockrock,
aggregation of solid matter composed of one or more of the minerals forming the earth's crust. The scientific study of rocks is called petrology. Rocks are commonly divided, according to their origin, into three major classes—igneous, sedimentary, and metamorphic.
..... Click the link for more information.
 formed by the consolidation of mud or clay, having the property of splitting into thin layers parallel to its bedding planes. Shale tends to be fissile, i.e., it tends to split along planar surfaces between the layers of stratified rock. Shales comprise an estimated 55% of all sedimentary rocks. The composition of shale varies widely. Shales with very high silica content may have been formed when large quantities of diatomsdiatom
, unicellular organism of the kingdom Protista, characterized by a silica shell of often intricate and beautiful sculpturing. Most diatoms exist singly, although some join to form colonies.
..... Click the link for more information.
 and volcanic ash were present in the original sediment. Large numbers of fossilsfossil,
remains or imprints of plants or animals preserved from prehistoric times by the operation of natural conditions. Fossils are found in sedimentary rock, asphalt deposits, and coal and sometimes in amber and certain other materials.
..... Click the link for more information.
 in shales may give them a high calcium content; such shales may grade into limestoneslimestone,
sedimentary rock wholly or in large part composed of calcium carbonate. It is ordinarily white but may be colored by impurities, iron oxide making it brown, yellow, or red and carbon making it blue, black, or gray. The texture varies from coarse to fine.
..... Click the link for more information.
. Shales that contain a large percentage of aluminaalumina
or aluminum oxide,
Al2O3, chemical compound with m.p. about 2,000°C; and sp. gr. about 4.0. It is insoluble in water and organic liquids and very slightly soluble in strong acids and alkalies. Alumina occurs in two crystalline forms.
..... Click the link for more information.
 are used as a source of that mineral in the manufacture of cementcement,
binding material used in construction and engineering, often called hydraulic cement, typically made by heating a mixture of limestone and clay until it almost fuses and then grinding it to a fine powder.
..... Click the link for more information.
, and those that contain natural gas and petroleum have become a significant energy resource in the 21st cent. due to the use of hydraulic fracturing techniques in drilling. Shales containing abundant carbonaceous matter grade into bituminous coalcoal,
fuel substance of plant origin, largely or almost entirely composed of carbon with varying amounts of mineral matter. Types

There is a complete series of carbonaceous fuels, which differ from each other in the relative amounts of moisture, volatile matter,
..... Click the link for more information.
.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/

shale

[shāl]
(petrology)
A fine-grained laminated or fissile sedimentary rock made up of silt- or clay-size particles; generally consists of about one-third quartz, one-third clay materials, and one-third miscellaneous minerals, including carbonates, iron oxides, feldspars, and organic matter.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

shale

Argillaceous sedimentary rock derived from clays or silts; typically thinly laminated and weak along planes; may be undesirable as a concrete aggregate.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

shale

a dark fine-grained laminated sedimentary rock formed by compression of successive layers of clay-rich sediment
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
The northwest and southwest sides are dominated by shaley lithology, deduced by the low resistivity values.
Geraint is lucky to be alive.' Safety on cliffs: Coastguard watch assistant Will Parfitt says people walking on cliffs should: Stick to the path; Not go too close to the edge; Be aware cliff edges can be shaley and give way; Be aware of cliff overhangs, where the cliff is eroded underneath the cliff top and can collapse; Call 999 and ask for the coastguard if they see anyone in trouble.
For a discussion of the broader conditions and consequences of politicization of these issues, see Walter Korpi & Michael Shaley, Strikes, Industrial Relations and Class Conflict in Capitalist Societies, 30 BRIT.
It was constructed using a poor quality shaley rubble with a thatched roof and the interior was fitted with traditional ``in and out'' panelling and a croglofft sleeping platform over half of the house.
Klassen (1983) reported that the upper gray clay was derived from shaley and calcareous till located to the south and southwest and the lower brown clays were derived from brown tills located to the east.
The Tuft, a shaley sandstone, and the Quarry Hazle, a sandstone, underlie the Great Limestone.
I put in an annual order for as much well-rotted cow manure as I could squeeze into the stable yard and laid it over the thin shaley soil as a mulch.
"I'm going back to ship normal for a while." I stood up on the shaley ground.
In the study area Roberts Creek flows along the contact of shaley Ordovician carbonates (Elgin Member, Maquoketa Formation) with underlying thinly bedded limestones of the upper Galena Group (Dubuque Member of Ordovician age; Hallberg et al.
prinus saplings, each 4 yr old, were planted alternately in an 8 x 10 grid on Berks shaley silt loam (Braker 1981) at a farm in Center County, Pennsylvania.