The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1916-10-05
Definitions of Mining Terms AS Sane
toned by U. S. Geological SURVEY

iochs, some deposits are freauenth
called bedded deposits, but this nam,
suggests that they were laid down a,
members of the photographic series il
"hich they occur-that is, that the,
are syngenetic deposits The term
bed deposit is of broader application,
II VIII cover such deposits as may have
been subsequently introduced between
the oeds-that is, epigenetic deposits
Cash Vein.
The term cash vein has been en-
ployed to describe a vein that fills
joints or assures in limestone in rho
lead deposits of the Mississippi val
ley region. A cash vein does not ex-
tend beyond a single bed or similar
rock mass.
True Vein.
whitney used the expression true or
assure veins in his tabular classified
ton of ore deposits to distinguish from
cash veins those veins which. accord
ing to him, may be presumed to ex-
tend for an indefinite distance down.
ward" Although in his text he uses
the term true Vein the expression he
employs in his widely quoted table has
probably given currency among miners
to the term 'tissure vein or even true
insure Vein.' True Vein was the
term in use before Whitneys table
was published, and by the earlier wrl-
ters on ore deposition it was employed
to indicate an ore body that filled n
flssure; hence the term 'fssure vein
is in strict sense pleonastic and
should not be used in classification.
Structure of Vein Material.
The following forms of structure
may be recognized in the material fill
ing a fissure:
l. Banded structure, in which the
Vein shows in cross section a band
ing nearly parallel to the wall This
may be subdivided, according to ORR
gin, into
(a) Banded structure by filing, in
which the filling is evidently a series
of layers of Vein material deposited
successfully on the walls of an open
space. If the layers are symmetric-
ally arranged on both sides of me-
dial plane, with crystals pointing in
ward, comb structure is produced. In
the middle part of the vein there may
be cavities or yugs filed with crystals
% Banded structure by subsequent
movement or ribbon structure. pro-
duced by simple sheeting of the vein
material after original deposition
Such movement may result in a re-
opening along the new plane of move
ment and the deposition of new ma
teria1 in the opening
(c) Banded structure by replace
ment, produced where the original fis
lei openings separated by thin bands
of country rock and where, during or
subsequent to the filling of these
openings, the intervening bands Of
country rock have been more or less
replaced by vein material.
2. Greccia structure, in which the
friction breccia or dragged-in frag-
ments of country rock constitute
considerable part of the vein filling
and the ore has been deposited in the
spaces between the fragments, per.
l. t,, 1noc
or layers around them. Breccia struc-
ture may occur in any vein, hence it
is not desirable to use "brecciated
vein" as a term of classification.
Linked Veins.
Deposits that fill approximately
parallel and overlapping assures, ar
ranged in steplike form and connected
or linked by small, irregular cross
stringers, are called linked veins. AS
the deposit pinches out on one fissufe
it is taken up on one of the overlap
ping assures.
Strnger Lode.
A stringer lode is made up of irreg-
ularly branching and anastomosihS
stringers or veinlets. In most string
err lodes the rock between the veinlets
is so much metallized or is so insep-
arabic from the stringers that the
whole is worked as single ore body,
Chimney. Stock.
s The term chimney" is applied TO
ore bodies thai have not the tabular
form of a vein, but ore rudely circular
or eIllptical i'll outline horizontally
and have very considerable vertical
extent. A similar body of still greater
irregularity of outline is called
stock.
Stockwork.
A stockwork is an ore body Of stock
like form made up of innumerab'e
branching and anastomosing stringers,
Ore Shoot, Pay Shoot.
An ore shoot or pay shoot is that
part of a metalliferous deposit which
is rich enough to exploit. It's outlines
are not generally well defined. The
ore shoot may be considered as hav'
ing three axes, at right angles to one
another. The inclination of the long
est axis to a horizontal plane is called
the plunge and is measured in YER
teal plane erected along the axis. The
angle made by this axis with hori-
zontal line, measured in the plane of
tha vein. is called the pitch In an ore