412 General Notes. [May, 
quartzite beds which rest upon the Wasatch granite. Some of 
the iron ore beds in this granite are distinctly interstratified with 
it, and are certainly, like it, metamorphosed sediments. This is 
plainly shown at the Blair mine, where the principal crest of the hill 
is a distinct sheet of stratified, regularly bedded magnetite, from 
thirty to forty feet in thickness, dipping toward the north at an 
angle of about eighty degrees. Parallel with this principal layer 
are other sheets of magnetite separated by strata of granite and 
varying from a quarter of an inch to ten feet in thickness, as per- 
fectly parallel and regular as any series of sedimentary beds ever 
seen. 
On the whole, the Blair mine is the most interesting and instruc- 
tive outcrop of iron known to me, and furnishes the most striking 
proof of the sedimentary origin of these wonderful ore beds. 
None of the other outcrops are so distinctly stratified, but the 
Big Blow-out at Iron city affords an equally conclusive argument 
against the eruptive theory ; for while it appears to be a huge 
amorphous mass, like a hill of basalt, on examination it is found 
to be in large part composed of metamorphosed limonite ; that 1s, 
» magnetite, which has the botryoidal and concretionary aspec 
radiated structure of limonite, and was plainly deposited from 
water. 
With the exception of the great iron deposits of Southern 
Utah, the far West is but imperfectly supplied with this metal. | 
have found magnetite and specular ores in small quantities in S¢V- 
eral places in the mountains of Oregon and California, and in the 
Rocky Mountain belt, and similar ores have been met with by 
rospectors and explorers in some of the districts which I have 
not visited. We have no evidence, however, that any other great 
deposits of iron exist in or beyond the Rocky mountains. Iftt 
is true, which I do not believe, that there are anywhere iron ores 
that are truly eruptive in character, it is somewhat surprising that 
in the immense area where igneous rocks predominate in the 
West, no masses of eruptive iron ore have been met with. W 
have reports of eruptive masses of magnetite at Nijni Tagilsk, 1" 
Russia, and of hematite on the island of Elba, but no observations 
have lately been made for the purpose of determining whether 
these are what they have been reported to be. The famous beds 
of magnetic and specular ore of Sweden have also been consid- 
ered, up to a recent date, as eruptive, but Professor Otto Torrell, 
Director of the Geological Survey of Sweden, with whom I was 
associated in the Centennial Exhibition, assured me that all the 
deposits of iron which he had visited in Sweden were metamor- 
‘phic and not eruptive, and that he had no faith in erupted ores 0 
iron.—F. S. Newberry, in School of Mines Quarterly, Nov., 1880. 
GrotocicaL News.—A paper on the uniclinal structure of 
the Iberian peninsula, by J. Macpherson, is published in Span- 
ish and English. A section of the rocks from the Mediter- 
