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crush line

A line along which rocks under great compression yield, usually with the
production of schistosity.

crush movement

Compression, thrust, or lateral movement tending to develop shattered
zones in rocks. Fay

crush plane

A plane defining zones of shattering that result from lateral thrust.
Fay

crush zone

A zone of faulting and brecciation in rocks. Fay

crust

a. The outermost layer or shell of the Earth, defined according to various
criteria, including seismic velocity, density and composition; that part
of the Earth above the Mohorovicic discontinuity, made up of the sial, or
the sial and the sima. It represents less than 0.1% of the Earth's total
volume. CF:tectonosphere
b. A laminated, commonly crinkled deposit of algal dust, filamentous or
bladed algae, or clots (from slightly arched forms to bulbous cabbagelike
heads) of algae, formed on rocks, fossils, or other particulate matter by
accretion, aggregation, or flocculation. AGI

crustal abundance

See:clarke

crustal plate

A portion of the Earth's crust that moves as a relatively rigid unit with
respect to adjacent crustal plates that collectively cover the outermost
part of the solid Earth. AGI

crustification

a. The layering of crusts of different minerals deposited successively on
the walls of a cavity.
b. Suggested for those deposits of minerals and ores that are in layers or
crusts and which, therefore, have been deposited from solution.

crustified banding

A structure of vein fillings resulting from a succession, often a rhythmic
deposition, of crusts of unlike minerals on the walls of an open space.

crustified vein

A vein filled with a succession of crusts of ore and gangue material.

crut

A short heading excavated into the face of a coal seam; a heading or drift
across the strata, or from one deposit to another. Syn:tunnel
Nelson

crutt

N. Staff.; Som. A road or heading driven in coal measures, turned from a
level, etc.

Cryderman loader

A clamshell-type loader activated by hydraulic cylinders operated from a
traveling base suspended on the stage. Used in shaft sinking operations.
Lewis

cryogenic switching elements

In information processing, logical switching information processing
elements that utilize the variability of the transition to
superconductivity as a function of magnetic field strength. Hunt

cryolite

A monoclinic mineral, Na3 AlF6 ; waxy colorless to white
(disappears in water owing to low refractive index); soft; in veinlike
cleavable masses in granite at Ivigtut, Greenland. Syn:Greenland spar;
ice stone.

cryolithionite

An isometric mineral, Na3 Li3 Al2 F12 ; forms
large colorless rhombic dodecahedra; at Ivigtut, Greenland, and the Ural
Mountains, Russia.

cryology

a. In the United States, the study of refrigeration. AGI
b. In Europe, a syn. for glaciology. See:glaciology
c. The study of ice and snow. AGI
d. The study of sea ice. AGI

cryoluminescence

The low-temperature increase of weak luminescence, or its development in
normally nonfluorescent material. AGI

cryopedology

The study of the processes of intensive frost action and the occurrence of
frozen ground, esp. permafrost, including the civil-engineering methods
used to overcome or minimize the difficulties involved. AGI

cryosphere

The part of the Earth's surface that is perennially frozen; the zone of
the Earth where ice and frozen ground are formed. AGI

cryoturbation

Frost action, including frost heaving.