Mineral Point tribune. [volume] (Mineral Point, Wis.) 1854-1858, 1854-04-20
CHAPTER III.


In determining the value Of a metalliferous dis
,rict, the first point 10 be settled is the mode in
Nlca the ores occur. Deposits of metallic ores
are divided into two classes. First, those which
oecur in beds punches or veins of limited extent
usually called cotemporaneoHs deposits. Second,
tie veins which are defined TO be "the mineral con
tents Of fssures having indefinite length and
depth The former are local and irregular, with
INCONSISTENCY of direction, and never extended from
ore rock to another. The latter, the contrary,
extend vertically to great but unknown depths.
and rravcrsng every variety of strata. They
may often be traced for many miles in horizon
-al direction, pursuing the same general course
throughout, and retaining their productiveness,
subject only to transient Interruptions. They are
enclosed between walls of rock, separated from
taer contained substances by distinct line of De
markation. The first class of deposits often give
promise Of a large yield but iaii when pursued
i9r a length of time. Millions of dollars have
been wasted in prosecuting mining operations up
On such deposit which seemed to give evidence OF
exhaustless stores of ore. The experience Of the
past has taught the necessity of great care in the
selection OF mining ground; and while it has proved
the danger Of adventures in those isolatedand lin
ireJ deposits however rich at first 1t has equally
established the safety Of liberal investments in the
exploration OF true metallic veins. All mines OF
tae globe distinguished of permanent value, be
long 70 this latter class. To this class also may
le referred most of the deposits of ere in the lead
district of Wisconsin. They generally present
the characters of true veins, and are therefore to
be treated and relied upon as such. This will be
evident, if we examine the general phenomena
"Aica they present.
REsRSG OF THE LEAD MINES.
The most general direction of the productive
veins is east and west The variation is usually
from three 70 twenty degrees south of east-some
times however it is north of east Local varia-
tons often occur in the general bearing OF the
lode but in most cases, ifpursued, II will be found
TO resume its original course. An average OF 1913
obseryatens upon lodes having an east and west
direction, gives mean variation of eleven degrees
from the meridian line
Another system Of veins of less frequent occur.
renee are termed norths and souths. These vary
from true north and south so that the mean of &C
observations is IL degrees. In many cases these
have direction nearly n. n, f. Still another
class are called quarterings. They intersect tht
casts and VESTS al an angle of about 10 degrees
and are often known as ten o'clock ranges Be
sides these, there are strings and branches appa
Tently flying off from the main ranges, and having
every conceivable direction-In a few Instances
productive veins probably by succession o
sAEows) assume a curved or crescent form, ant
are hence called horseshoe ranges" The east,
and VESTS have probably yielded nine-tenths of al
The ore raised in the district and must be regardel
as the characteristic or principal veins.
HomzoSrAL EXTENT OF Yk1ss.
Many of these veins are Of great length. Seve
raj Of them have been traced three or four miles
pursuing their general course with such constapc,
that when struck, tie compass may be used :,
discover their location al great distance. Th
Heathcock range" in the town of Linden ha
been worked for nearly mile continuously. an,
It's extent for three miles ascertaJned bv occasion
al shafts, which have been sunk upon il Tn
Long Range, al Potosi, and the Great Blackles
II town I, range , east, have each been worked
mile in length. The breadth OF the veins yarie
from few inches 10 50 feet or more
Ito Be Co,,fiiisea)