388 The American Geologist. December, is'jg 
Professor Todd well describes the deep trouffh-like valleys or gorges 
of the Missouri and Mississippi rivers, with numerous cross-sections, 
and discusses the Quaternary changes and evolution of these great 
streams. 
Correlating the Missouri glacial drift with that of the states farther 
north, he notes the changing conditions of the Kansan, Aftonian, 
lovvan, and Wisconsin stages or epochs, as pamed by Chamberlin: and 
he ascribes the snow and ice accumulation mainly to high uplift of 
northeastern portions of the continent. He thinks, however, that the 
ice-sheet, although extending into Missouri, did not reach quite to the 
limits of the drift and striae, which, on the border, are attributed to 
floes and bergs. w. u. 
Tlie Production of Ivan Ores in 18!>5. By John Birkinbine. (Ex- 
tract from the Seventeenth Annual Report of the United States Geo- 
logical Survey, pp. 1-27, 5 maps. Washington, 1896.) This paper, which 
will form the first portion of Part III of the 17th annual report, has 
just appeared in pamphlet form. Michigan held first place in 1895 with 
a production of 5,812,444 tons. Minnesota stood second, with a total of 
3,866,453 tons. Alabama was third, with 2,199,390 tons to her credit, 
and Pennsylvania, Virginia, Wisconsin, Tennessee, New York and New 
Jersey followed in the order named, no one of them having produced as 
much as a million tons and their combined output Vjeing less than that 
of Minnesota. The iron ore production of the Lake Superior region in 
1895 was 10,268,978 tons or 62.31 per cent, of the output of the entire 
country. This is more than double the maximum output of the Bilbao 
district in Spain, and the average quality is not equalled by any other 
large producing district. Sketch maps showing the location of the ac- 
tive mines on the five Lake Superior ranges, and brief accounts of the 
conditions obtaining on each of them add to the value and interest of 
the report. 
Special attention is paid to the Mesabi iron range, and the Minnesota 
Geological Survey is congratulated "upon having pointed to the region 
now known as the Mesabi range as a probaljle iron ore producing dis- 
trict prior to active explorations." The estimated amount of iron ore 
that this new range (which in 1895 produced 27.6 per cent, of the Lake. 
Superior output) can furnish is put at the very moderate total of 200 
million tons. The average tonnage value of Minnesota iron ore at the 
mines was only $0.73 as against an average value of $1.45 for Michigan 
and $1.14 for the whole country. On the other hand, the average iron 
content of Minnesota ore is not less than 62 per cent., while that of the 
country at large is about 54 per cent., and " the phosphorus in non-bes- 
semer Mesabi ores is below that of the average non-bessemer ores of the 
country." 
Foreign ores imported into the United States in 1895 amounted to 
524,153 tons with a total value of $786,207. 
In compai-ing these figures with those given by the Iron Trade Re- 
view and other authorities it should be remembered that these are data 
of actual production at the mines and other figures are usually those of 
