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veil

a. A removable plate to cover a screen, the action of which is not
desired. Zern
b. An aggregate of minute bubbles creating a whitish or cloudlike
appearance in quartz.
c. A variously formed weblike or netlike film in a radiolarian; e.g.,
patagium.

vein

a. An epigenetic mineral filling of a fault or other fracture in a host
rock, in tabular or sheetlike form, often with associated replacement of
the host rock; a mineral deposit of this form and origin. CF:lode
See also:true vein
b. A narrow waterway or channel in rock or earth. Also, a stream of water
flowing in such a channel. AGI
c. A thin, sheetlike igneous intrusion into a fissure. Not recommended
usage. AGI
d. A coal seam or a bed of slate or other rock. Not recommended usage.
BS, 11
e. A zone or belt of mineralized rock lying within boundaries clearly
separating it from neighboring rock. It includes all deposits of mineral
matter found through a mineralized zone or belt coming from the same
source, impressed with the same forms and appearing to have been created
by the same processes. Ricketts
f. A mineral deposit, usually steeply inclined. Used to describe a body
that is usually smaller and has better defined walls than a lode.
Nelson
g. A rock fissure filled by intruded mineral matter. Many valuable
minerals are codeposited with gangue stuff in veins. Usually the formation
is steep to vertical, unlike a bedded deposit in which values are
sandwiched horizontally. Vein is typically long, deep, and relatively
narrow. Pryor, 3
h. The term lode is commonly used synonymously for vein.
i. The filling of a fissure or fault in a rock, particularly if deposited
by aqueous solutions. When metalliferous, it is called by miners a lode;
when filled with eruption material, a dike. A bed or shoot of ore parallel
with the bedding. Also called blanket deposit. Standard, 2
j. A comparatively thin sheet of igneous rock injected into a crevice in
rock. When this intrusion is large, it is called a dike.
k. An irregular, sinuous, igneous injection, or a tabular body of rock
formed by deposition from solutions rich in water or other volatile
substances. Holmes, 2
l. A mineral body, thin in relation to its other dimensions, which cuts
across the bedding and in which the minerals are later than the country
rock. BS, 11
m. Sometimes used for a bed; e.g., a coal seam or a bed of slate.
BS, 11
n. A layer, seam, or narrow irregular body of material different from
surrounding formations. See also:vein or lode claim

veined gneiss

A composite gneiss with irregular layering. The term is generally used in
the field and has no genetic implications (Dietrich, 1960). CF:venite;
composite gneiss. AGI

vein intersection

a. The depth in the borehole at which the hanging and/or footwall of a
vein is encountered. Long
b. The place where two or more veins cross or meet. Long

vein material

See:veinstuff

vein miner

A miner experienced in the winning and working of mineral veins.
See also:metal mining

vein or lode claim

The terms "vein or lode" and "vein or lode claim" are used
indiscriminately and interchangeably, and it follows that the term "vein
or lode" is intended to be synonymous with the term "vein or lode claims."
See also:vein; lode; lode claim. Fay

vein quartz

A rock composed chiefly of sutured quartz crystals of pegmatitic or
hydrothermal origin and commonly of variable size. AGI

veinstone

The valueless stone that occurs with the valuable minerals in lodes and
veins. Also called lodestuff; matrix; vein mineral; veinstuff. Sometimes
mistakenly called gangue. Nelson; Fay

veinstuff

a. All the minerals occurring in a vein. See also:lodestuff
b. Gangue. Syn:vein material

vein system

An assemblage of veins of a particular area, age, or fracture system,
usually inclusive of more than one lode. AGI

velardenite

See:gehlenite

velikhovite

A variety of pyrobitumen having a shining conchoidal fracture and
occurring in the form of veins. It is partly soluble in organic solvent;
sp gr, 1.2. In many ways it is similar to grahamite. It is assumed that it
represents a weathering product of albertite. From the South Urals,
Russia. Tomkeieff

velocities in pipes

Experience has proved that the following are allowable velocities in
pipes: air, 30 to 50 ft/s (9.1 to 15.2 m/s); compressed air, 25 to 40 ft/s
(7.6 to 12.2 m/s); steam, 160 to 250 ft/s (46.8 to 76.2 m/s); water, 5 to
10 ft/s (1.5 to 3.0 m/s). Hammond

velocity

a. In explosives, the speed (in meters or feet per second) at which the
detonating wave passes through a column of explosives. A high-velocity
explosive renders a shattering effect, whereas a low-velocity explosive
has a pushing or heaving effect. Syn:high velocity
b. Linear flow rate of air per unit time. Measured in meters per second.
Hartman, 1
c. A vector quantity that indicates a time rate of motion. AGI

velocity determination

The determination of velocities and average velocities within the earth by
seismic measurements. AGI

velocity discontinuity

An abrupt change in the velocity of propagation of seismic waves within
the earth, as at an interface. AGI

velocity distribution

Relationship between seismic wave velocity and depth.
Schieferdecker

velocity head

a. The constant difference of height of a liquid between a level surface
in a tank and a uniformly flowing jet through an orifice.
Standard, 2
b. The distance a body must fall under the force of gravity to acquire the
velocity it possesses. See also:kinetic energy
c. The energy possessed per unit weight of a fluid owing to its velocity.
If at a given point the velocity is v feet per second, the velocity head
at this point, v2 /2g, g being the acceleration due to gravity in
feet per second squared. Also called kinetic head.
Syn:velocity pressure

velocity lag

See:distance lag

velocity meter

A seismometer used to record the velocity of ground motions. AGI