250 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull. 213. 
were noted. Facts were collected that seemed to indicate that the 
phosphorus in these districts, as in the Mesabi district, is the result 
of the concentration of the percolating waters rather than a residual 
product, and that the precipitation of the phosphorus from such 
waters may be in some way connected with aluminous compounds in 
the ore, notwithstanding the fact that some of the phosphorus is now 
present in the ores as apatite, as shown by Prof. A. E. Seaman, of 
the Michigan School of Mines. 
MOOSE MOUNTAIN DISTRICT. 
Late in the season a visit was made to the new iron-bearing dis- 
trict, the Moose Mountain district, northeast of Lake Superior. Mag- 
netite ore was observed in large quantities. This is the first district 
in which iron ores in large quantity have been discovered in Canada. 
The district in its geologic features resembles the Vermilion of Min- 
nesota more closety than any other district, and because of this 
resemblance the Moose Mountain iron-bearing rocks are supposed to 
be of Archean age, although no structural connection of the two dis- 
1 nets is possible. The ores are closely associated with quartzites and 
graywackes bearing iron pyrites, and alterations of iron pyrites to 
iron ore may be observed on a small scale, and these facts, together 
with the abundance of other sulphide ores in this area, lead us to sus- 
pect that further work may sho*v r llie origin of the iron ores to be in 
some way connected with the iron pyrites. 
