Tron Ores of Minnesota.—lV inchell. 157 
lished by the present survey, and the trend of the Mesabi range 
was actually mapped prior to the discovery of any of the great 
ore bodies that are now known at Biwabik and Virginia.” 
The Geological Survey has been in the heat of the campaign 
from the beginning to the present. It has seen every test-pit, 
and has noticed the result. It has advised every mining com- 
pany, at least if its advice was asked. It has urged explora- 
tions in certain places, and it has had the unpleasant duty to 
discourage it in others, sometimes after many thousands of 
dollars had been invested. It has been a constant attendant, 
and sometimes a leader, in every important phase of this 
march.” ‘ 
Since the commencement of shipments of iron ore from 
Minnesota, the state has steadily advanced in rank amongst 
the iron-producing states. The first shipment was made in 
1884. Last year the amount shipped was 9,834,399 long tons, 
and that of Michigan, the leader in this industry, was but 92,- 
328 long tons greater, these two states furnishing more than 
one-third the total output of the United States. 
Geological relations. While the ores now exploited are de- 
rived from two formations, there are four formations in Min- 
nesota that contain notable amounts of iron ore, and these all 
may in the future become productive in commercial amounts. 
These formations are as follows, the oldest at the bottom: 
1. The Cabotian gabbro. | ee 
2. The Animikie taconyte 3 
3. The Upper Kewatin jaspilyte. } 
4. The Lower Kewatin jaspilyte. 3 
Of these, Nos. 2 and 4 are at present the only productive 
formations. The former (No. 2) is found in the Mesabi 
range and the latter (No. 4) on the Vermilion range. They 
both furnish hematite, that from the Mesabi range being 
“soft,” and that from the Vermilion range being usually hard. 
The Chandler mine at Ely, however, on the Vermilion range, 
supplies an ore that is easily mined, and is sometimes denom- 
inated “soft.” Some of the largest mines on the Mesabi range 
are simply great open pits, from 50 to 150 feet deep, into 
which steam cars and steam shovels are run on a gentle grade, 
Archean. 
+ This map, however, was not published till June, 1891, shortly after the 
first important discovery, the Mountain Iron Mine, wus publicly known. 
