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discharge

a. The production or output from crushing or processing machines, such as
ball mills, or thickeners.
b. The outflow from a pump, drill hole, piping system, or other mechanism.
c. The quantity of water, silt, or other mobile substances passing along a
conduit per unit of time; rate of flow in cubic feet per second, gallons
per day, etc.
d. The rate of flow at a given moment, expressed as volume per unit of
time. AGI

discharge chute

A chute used to receive and direct material or objects from a conveyor.

discharge head

The sum of static and dynamic head. The vertical distance between intake
and free delivery of pump is static head. Allowance for friction, power
loss, propeller slip, and issuing velocity is made for calculating the
overall discharge head. Pryor, 3

discharge station

A place where bulk materials are removed from a conveyor.

discomfort glare

A sensation of annoyance, or in extreme cases pain, caused by high or
nonuniform distribution of brightness in the field of view. Discomfort
glare is a measure of discomfort or annoyance only.
CF:disability glare

disconformity

An unconformity in which the bedding planes above and below are
essentially parallel, indicating a considerable interval of erosion (or
sometimes of nondeposition), and usually marked by a visible and irregular
or uneven erosion surface of appreciable relief. The term formerly
included what is now known as paraconformity. Syn:parallel unconformity;
nonangular unconformity. See also:angular unconformity

discontinuity

a. An abrupt change in the physical properties of adjacent materials in
the Earth's interior. Mather
b. Any interruption in the normal physical structure or configuration of a
part, such as cracks, laps, seams, inclusions, or porosity. A
discontinuity may or may not affect the usefulness of a part.
ASM, 1

discontinuity lattice

See:lattice

discontinuous deformation

Deformation of rocks accomplished by rupture rather than by flowage.

discontinuous reaction series

A reaction series in which early-formed crystals react with later liquid
by means of abrupt phase changes; e.g., the minerals olivine, pyroxene,
amphibole, and biotite form a discontinuous reaction series.
CF:continuous reaction series

discordance

A lack of parallelism between contiguous strata, e.g., angular
unconformity. Standard, 2; Fay

discordant

a. Said of a contact between an igneous intrusion and the country rock
that is not parallel to the foliation or bedding planes of the latter.
AGI
b. Structurally unconformable; said of strata lacking conformity or
parallelism of bedding or structure. CF:concordant
Syn:unconformable

discordant bedding

See:crossbedding

discovery

a. In mining, the term may be defined as knowledge of the presence of the
valuable minerals within the lines of the location or in such proximity
thereto as to justify a reasonable belief in their existence. But in all
cases there must be a discovery of mineral, in both lode and placer
claims, as distinguished from mere indications of mineral. In other words,
in a lode location there must be such a discovery of mineral as gives
reasonable evidence of the fact either that there is a vein or lode of
rock in place carrying the valuable mineral; or, if it be claimed as
placer ground, that it is valuable for such mining. Ricketts
b. Pac. The first finding of the mineral deposit in place upon a mining
claim. A discovery is necessary before the location can be held by a valid
title. The opening in which it is made is called discovery shaft,
discovery tunnel, etc. The finding of mineral in place as distinguished
from float rock constitutes discovery. See also:mine

discovery claim

A claim containing the original discovery of exploitable mineral deposits
in a given locale, which may lead to claims being made on adjoining areas.
AGI

discovery vein

The original mineral deposit on which a mining claim is based.
CF:secondary vein; discovery claim. AGI

discretization

In kriging, the process of approximating the area of a block by a finite
array of points.

disequilibrium assemblage

An association of minerals not in thermodynamic equilibrium. AGI

dish

a. See:pan; gold pan.
b. The landowner's part of the ore. Fay
c. Gold-bearing gravel or other material found by panning.

disharmonic fold

A fold that varies noticeably in profile form in the various layers
through which it passes. Ant: harmonic fold. AGI

disharmonic folding

Folding in which there is an abrupt change in fold profile when passing
from one folded surface or layer to another. It is characteristic of rock
layers that have significant contrasts in viscosity. An associated
structure is decollement. Ant: harmonic folding. CF:decollement
AGI