The Barre daily times. (Barre, Vt.) 1897-1959, 1913-06-10
RICH IN GOLD AND SILVER.
Helena Mining Region in Montana Has
Produced $4,000, 900.

A report recently issued by the United
States geological survey describes the
geology and ore deposits of several of
Montanas oldest and best known camps,
which have contributed at least $780,
100000 in gold, silver, and lead to the
worlds wealth.
The first important find of metallic
wealth in Montana was the discovery OF
iplacer gold at Bannock in 1862. In the
following year the far greater discovery
lat Alder GlIlch was made, and from this
stream was taken within the next three
years $30,000,000. The extraordinary
richness of these placers Immediately at
tracted large population. and so strong
was this influx that within Is months
a town of 10000 people sprang up, which
was named Virginia City. Alder creek
was the longest and most productive
creek ever discovered in Montana; 20
miles of stream bed, compromising about
! 900 claims, were worked and yielded a
profit at time when wages were from
$40 to $l4 day.
Montana was soon overspread by eager
prospectors, and in the next few years
all the important placers were discov
cred. Last Chance, on the present site
of Helena, the capital of Montana, was
located in the summer of 1864. The
Whitlatch- Union vein, carrying rich gold
ore, was found few miles south of
Helena in September of the same year.
Lode and placer discovery were thus con
temporaneous. The finding of gold in
place caused quartz excitement which
stimulated prospecting all over the ter
ritory.
The survey report, issued as bulletin
52T. "Ore Deposits of the Helena Mining
Region, Montana" by Adolph Knopf, |
covers an area of 1000 square miles in |
southwestern Montana, comprising the |
southern part of Lewis and Clark coun-
ty. the northern part Of Jefferson coun- ,
ty. and the southeastern part of Powell I
II includes the Elkhorn, Marys-
Vile, Elliston. Rimni, Helena, Clancy,
Wickes, and the Boulder and Basin min
ing districts.
The Continental divide, at an average
elevation of 1000 feet, traverses the
western part of the area shown on the
geologic map which accompanies the re-
port The highest peak, Red mountain,
Ia miles southwest of Helena, is $500
feet above sea level The region has
a considerable and abrupt relief but is
characterized by smoothly rounded hills.
Boulder river is the largest stream in
The region. though Missouri river crosses
the extreme northeast corner of the
urea.
Immense Volcanic Flows.
The Helena region is at the north end
L. =. a. I,tb |
,lith, an immense mass of granite"
which was thrust into sedimentary and
gneous rocks. The older rocks are main
Y limestones, shsles and quantities.. over 6
ain by immense deposits of volcanic '
lows and breccias. Into tbs series of II
ocks, which was at least $500 feet Nv
bick, the liquid granite rock forced its i
way upward. The granitoid rock, To- il
ally called granite" but in fact true I
uartz monzonite, now underlies the Il
anger part of the Helena mining re- t
ion. After a considerable time the re- r.
ion was again the site of volcanism and 4,
ayas aggregating 2,400 feet in thick t
ess We're poured out upon the eroded It
urface of the older formations. 10
Ores Formed Under Great Heat
The ore deposits, according to Mr.. a
.nopf. fall into two distinct groups in Il
oint of age. The older deposits, clear T,
7 related to the intrusion of the quartz ii
lonzonite, are mainly productive of sill d.
er-lead and gold-silver ore and have b
ielded three-fourths of the wealth OF m
ne district. These deposits are COM h,
Ionly located enar the granite" con- f
let, either in the granite" or in the II
der andesitic rocks They are replace al
ent lodes carrying galena, sphalerite, is
write, and arsenopyrite and are COM gi
only associated with heavy black tour 10
aline. This mineral is associated with fe
lie tin lodes of Cornwall England. The tie
'sociation of tourmaline with lead sill to
IT ores has never been described be-
re and is in fact most remarkable. te
5 presence, together with other evil fr
nee given in the report. shows that hi
e ores must have been formed at We