L56 
The American Geologist. 
March, 1894 
Mater, the mine superintendent, the writer had the borings in 
the foot wall continued to the gneissic rock. In fig. 2 the 
line a-x represents the position and direction of the drill 
hole. The core of the drill was preserved and tested by the 
writer with hydrochloric acid. The result was what was ex- 
pected. Between the magnetite bed and the franklinite tin- 
core preserved was ten feet long, which is probably about 
one-hall' of the entire distance. This makes the thickness of 
the limestone foot wall at this point practically the same as 
at the surface. 
Fig. 'I.— Section through No. 4 shaft. 
1. — White dolomite, coarsely crystalline. 2.— White limestone, coarsely crystalline. 
3. — Ore body, mined out. 4. — Dolomite foot wall. 6.— Magnetite bed. 5.— Gneiss. 
Samples of the core were carefully selected for analysis. 
The result is as follows : 
III. 
Insoluble 0.6G 
Fe 2 3 +Al 2 3 1.55 
CaC0 3 54.31 
MgC0 3 43.92 
Total 100.44 
What is more remarkable than the above is an analysis of a 
stratum of limestone midway between two lenses of franklin- 
ite ore. The stratum, as indicated by the drill core, is about 
ten feet thick, and is thickl} T sprinkled with crystalline grains 
of franklinite. An analysis gave the following result: 
~ m. 1 
Insoluble 0.39 
Fe 2 3 -|-Al 2 3 4.58 
CaYj6 3 63.81 
MgC0 3 29.82 
Total 98.60 
