The diamond drill. (Crystal Falls, Iron County, Mich.) 1887-1996, 1913-02-15
DEVELOPMENT or NEW ORE ON
WEST SIDE IS INTERESTING
DEEP SURFACE CAUSES TROUBLE
Caspian and Zimmerman Are Started and
TuIly viii Have TO be Started on
Special Systems.


on the west side of the county have
brought with them problems that have
not been easily solved. Many of the
operators have before them difficulties
tnat some years ago would have seem.
ed unsurmountable.
The greatest difficulty to overcome
Ia the opening OF the new tnds lie the
disposition of the big sand overburdens
resting on the ore and, while some OF
the mines have gotten we'll along to-
wards solution Of the problem, there
are yet many difficulties 70 be met
with and conquered.
Another condition, unforeseen several
years ago, 10 the demand OF the fee
owners tnat the ore be mined and not
wasted. In some cases engineers are
employed by the fee owners to watch
the mining Of ore on properties that
they have leased to mining companies
and Ii is Thought that before long this
practice will become general. IL start.
cd first on the Mesabi range where one
Of the thorns in the flesh of the opera
tor Is the presence of the engineer re.
presenting the tee owner and his insis
tence that every pound OF ore available
be taken out of the property. 1t is
stated that exactions of the fee owners
on Mesabi properties have materially
Increased the mining costs Fingers OF
ore must to followed and taken out
and, 10 do 50. underground mining must
be resorted TO in many cases.
At tho Zimmerman mine Of the
Stambaugh district the fee owners
have placed al agent 10 watch develop
ment and exact the proper mining Of
tho ore so that every pound available
will be taken out and not left buried
nnder rock and sand in the mine.
AS stated. the big sand over burden
pmust be taken care of. Under the old
system Of square set timber mining the
problem of mining tho ore and holding
the backs and walls intact was taken
care Of but depth aud the necessity OF
lowering the costs sent the old square
set method TO the discard and IN its
place camo the caving aystem which
originated ia the north Of England but
has been expanded and varied 10 such
an extent in the land of its adoption
that 1t would not know itself SHOULD II
return home.
The caving system. in some form, is
used at every property in the Iron
county districts. With properties of
shallow overburden the problem OF car
ing for the rock and sand that follows
the ore down la mass called the
gob' Is a comparatively simple affair
but In properties whore the sand over
burden is one hundred or two-hundred
feet thick, the problem becomes an a.
cute one and its acuteness Is added to
by the demand OF the owner that only
minimum amount of the ore must. be
sacrificed In the operation.
Water in the sand is another taUtor
Of difficulty and in all OF the heavily
overburdened properties Of the west
side the sand Is saturated with water
Two such properties, well opened up,
and the TnlIy. which Is about 10 be
opened up. will serve to illustrate the
difficulties that have TO be encountered.
The Caspian. the largest body OF ore
on the west side OF the county, carried
above the ore surface ~ about ii5
feet Of sand. quick sand. gravel and
boulders, The ore deposit IL very
large one and Is irregular in iron con.
tents. II has fingers os rock penetrat
ing Il at various points. The systvm
adopted at this property Is the top slIc-
ing. frat worked out at the Lake mine
0f the Cleveland tEs company alter
the water was pumped out of Lake
Angoline and the body OF silt ia the
bed Of the lake required some method
which would hold IL from running
down through the ore that was being
mined below. The system was expan.
ded upon the Mesabi range where the
blanket formation. comparatively shal.
low. and the pig overburden necessita.
ted system similar 10 that at The
Lake mine.
The Caspian ore body Is cut by uni
form levels 100 feet In thickness. the
main level being used for tramming
and general ingress and egress pur-
poscs. Tho mining is all done In sub
levels run of at uniform thickness
from the raises put up from the main
level. The first sub was tho most
difficult 20 manage as there the opera
tors were no against the sand The