Slaty cleavage

Also found in: Encyclopedia, Wikipedia.
(Min.) cleavage, as of rocks, into thin leaves or plates, like those of slate; - applied especially to those cases in which the planes of cleavage are not parallel to the planes of stratification. It is now believed to be caused by the compression which the strata have undergone.

See also: Slaty

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
Mentioned in ?
References in periodicals archive ?
About 3 m above the contact, the Chain Rock member displays bedding that is deformed into a tight fold that produces strongly curved intersection lineations on the regional slaty cleavage, showing that the cleavage transects both limbs of the fold (Fig.
Associated with these folds a slaty cleavage in the slates ([S.sub.1]) and a rough cleavage in the quartzites are developed (Figs.
These early cleavages are not precursors to slaty cleavage, and are essentially ephemeral features, though they could provide another anisotropy on which later cleavages might nucleate.
If silica from detrital grains was being mobilized during [S.sub.a] formation, then the absence of fringes around other detrital grains may indicate very low strain, or at least strain that is well below the threshold defined by Reks and Gray (1982), and certainly less than the 40-60% shortening generally cited for conditions of incipient slaty cleavage formation (Kisch 1989, 1991).
Slaty cleavage is moderately well developed in fine-grained lithologies and generally trends north and dips steep to the east (Fig.
Earliest structural elements in the turbidites include a slaty cleavage ([S.sub.1]) that is close to being bedding-parallel in most places.