The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1916-10-05

A
Gently been issued by the United
states geological survey entitled
suggestions to Authors of Papers for
publication by the United States Geo
logical Survey" by George McLane
Wood. While issued primarily for the
benefit of biologists and others of
kindred professions, and gives them
some wholesome advice in the matter
OF using technical terms in preparing
reports on mining districts and indi-
yidual mining enterprises, it also con-
tains much of interest to the non.
technical class who are interested in
mining. After outlining the correct
form of reports, Mr.. Wood gives the
following definitions:
Ore.
ore is mineral or rock from which
one or more metals may be profitably
extracted. Material that can rot be
profitffably worked today may become
of economic value year or so hence
without any change i'm character Con-
sequently, in using the term "ore" it |
is necessary to take into account the
effect of changing economic conditions
and of probable improvements in met
allurgic processes. According to the
definition given above it is tautologlc
TO use the term pay ore"
Gangue.
The term 'gangue" is properly APP
plied.only to the earthly or non-me-
tallic minerals that are of common
occurrence in ore deposits such as +
quartz, barite, chlorite, fluorite, cal.
cite and dolomite. The practice of
describing as gangue any metallic
minerals that may happen to be of no
economic value is not desirable, even
it they are called metallic gangue
for it permits no uniform distinction
between ore and gangue.
In describing the minerals occur
ring in an ore deposit it is well to
distinguish the exogenous gangue
minerals those that have been
brought in from some outside source
from the indigenous gangue min 9
erals-those that are the product of
alteration of the wall rock or country q
rock.
Vein Material.
As a collective term to describe the +
aggregate materials which make up b
the ore body, the phrase vein ma
teriar' or "vein stuff" may be used. n
Vein stone is less desirable phrase d
for the reason that "stone" is used by n
some mining men as a technical term s
for ore, whereas others make vein q
stone" synonymous with "gangue." n
Gouge. t
Gouge is a soft, clayey material that
occurs in some places as a selvage n
and is usually formed by the tritura- Il
tion of the country rock by motion o
subsequent to the formation of the s
vein. The term should not be loosely o
used for any soft, crushed material c
Country Rock. e
Country" is the miners term for
the rock which encloses an ore de- f
posit The term country rock has n
been criticized as tautologic; never C
theess, it is sanctioned by very wide a
usage, and its use is considered ad- S
visable where the single word "coun- h
try" might lead to confusion in the o
mind of the technical reader. t
Vein, Lode, Vein System. il
The material filing fissure, when y
not injected as molten matter to form
dixie, is termed a vein. Most veins
are of nearly tabular form. An ore r
bearing vein is a single body of metal r
liferous minerals occupying or follow Q
ing fissure, both walls of which gem 5
orally are we'll defined. Where several t
veins are so closely spaced that the i
ground between them becomes in 7
places ore bearing and in it's whole
width constitutes an ore body, the
assemblage is called lode, although I
in legal phraseology lode or lead Is IN S
a broad sense synonymous with Vein e
The term vein system may be used i
for a larger group Of veins and may 8
of the earth's crust that admit OF
ore deposition are so multiform that
it is not possible to give stricter de- {
finitions. Usage may differ somewhat (
in different districts, but the general c
order from simpler to more complicat- 8
ed deposits will be vein, lode vein c
system.
Shear Zone. S
The term shear zone" denote sa sec
ton of the earth's crust within when
the rocks have been closely laminateu ]
by yielding to shearing stress IL
Is a structural feature along whlch
ore may be deposited, but is not ltselr
form of deposit. /
Sheeted Zone.
Where the country rock is traverseo g
by approximately parallel assures {
separated by thin sheets of rock IL Is
said to be 'sheeted and the zone ar
feeted may be called a 'sheeted zone IL
In a sheeted zone the assures are
generally more widely spaced ana
there is less crushing than in smear L
zone.