The Extension of the Montana Phosphate Deposits Northward into Canada
"The Extension of the Montana Phosphate Deposits Northward into Canada" is an article from Proceedings of the National Academy of Sciences of the United…
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62 Geology: Adams And Dick
the alternating group of this degree gives clearly a much smaller value
ft
for this upper limit, when n becomes large, then the expression- + 1,
which is found in the standard works of reference, for instance, in Pascal's Repertorium der hoheren Mathematik, volume 1, (1910), page 211. It may therefore be of interest to note that it is possible to deduce from the italicized theorem noted above a general expression which gives still smaller values for the upper limit in question.
In fact, if p is a prime number in the interval y/n (exclusive) and 2 — 2 (inclusive) then r can always be so selected that it does not exceed p + n/p. Since this expression is an increasing function of p when p s/n and has the value f \/n when p 2\/n, it results that the prime number p can be so chosen that r is always less than f \Af — 1. That is, the degree of transitivity of a substitution group of degree n which does not include the alternating group of this degree is always less than — 1. For all integral values of n>43 this theorem gives a smaller upper limit for the degree of transitivity than the formula 1, and for all values of w>4 it gives a smaller upper limit than 3\/n — 2.
The Extension Of The Montana Phosphate Deposits Northward Into Canada
By Frank D. Adams and W. J. Dick
COMMISSION OF CONSERVATION OF CANADA Received by the Academy, January 10. 1916
With the development of agriculture in Western Canada there will arise in the not distant future an insistent and ever increasing demand for fertilizers and manures. Phosphoric acid is one of the most impor- tant constituents of such fertilizers. While no deposits of phosphates have hitherto been found in Western Canada, great beds of phosphate of lime have in recent years been discovered in Utah, Idaho, Wyoming, and Montana.
It was for the purpose of ascertaining whether these phosphate- bearing rocks extend northward into Canada that the present investi- gation was undertaken by the Commission of Conservation of Canada.
The phosphate beds from Utah to Montana occur at a certain definite horizon, usually known as the Phosphoria Formation, which is found near the summit of the Pennsylvanian subdivision of the Carboniferous system. This Pennsylvanian is usually composed of four formations, the phosphate lying at the base of the highest of these members and being usually associated with bands of chert.
Geology: Adams And Dick 63
The phosphate deposits in the United States which are nearest to the Canadian line are those which are found near Helena, Montana. Further north the great Louis overthrust comes in carrying the Cambrian and Pre-Cambrian over the Carboniferous, which, however, reappears at the Canadian boundary in the Flathead country.
The Carboniferous in Western Canada is practically confined to the Eastern slope of the Rocky Mountains in Alberta and the adjacent parts of British Columbia.
An examination of these mountains was, therefore, made along three transverse lines of sections, viz., (1) The North Kootenay Pass; (2) The Crows Nest line of the Canadian Pacific Railway; (3) The main line of the Canadian Pacific Railway.
The North Kootenay Pass crosses the Rocky Mountains about 20 miles north of the international boundary line. A geological recon- naissance along this line was made by G. M. Dawson, when Geologist to the Commission appointed to establish the international boundary on the 49th parallel. A great development of Devono-Carboniferous rocks is shown in Dawson's section, both to the east and the west of the Flathead Valley. To the east a block of these strata is represented as being thrown down between two faults, this faulted block being capped by a series of 'red beds' regarded by Dawson as of Triassic or Permian age, having been correlated by him with a similar series of beds found by Meek in Utah. If this correlation is correct a phosphate- bearing horizon might be expected a short distance below the base of the 'red beds' in question. An examination of this district, however, showed that only one fault existed and that the section contained no rocks of Carboniferous age. A thick series of Devonian limestones directly overlie a thinner series of orange limestones and shales in which was discovered an abundant trilobite and brachiopod fauna (the Albertella fauna), which fixes the age of these strata as belonging to an horizon near the base of the middle Cambrian. The underlying quartzites 'red beds' and limestones, are, therefore, of lower Cambrian or Pre-Cambrian age. The proper horizon for the phosphate of lime does not exist, there- fore, in this portion of the North Kootenay Pass.
An examination of the Crows Nest Pass section shows that here on Turtle Mountain only Devonian or Lower Carboniferous limestones are present, and these are directly, overlain by a strata of Jurassic age. In the third section, that on the main line of the Canadian Pacific Railway where this crosses the Rocky Mountains Park near Banff, the Carboniferous occurs in great volume and with a development very similar to that in Montana. There is the fourfold division as shown
64 Geology: Adams And Dick
by Allan who has mapped this area for the Geological Survey of Canada. From stratigraphical and paleontological considerations the authors were led to the conclusion that the horizon equivalent to the Phosphoria formation of the south was that at the contact between the Rocky Mountain quartzite and the Upper Banff limestone of Allan's section. These formations are repeated by faulting and appear as a set of parallel bands which cross the area four times in a general northeast and south- west direction. Forty Mile Brook crosses the contact three times, and a search was accordingly made in the shingle and loose blocks carried down by the stream, for 'float' of phosphate rock. This was found in the stream at the foot of Stony Squaw Mountain. The phosphate rock is of a hard compact variety which somewhat resembles basalt, a type found in certain of the Montana deposits. It contains 54% of tri- calcic phosphate. An examination of the mountain itself showed that a heavy band of chert occurs along the contact of the Rocky Moun- tain quartzite and the Upper Banff limestone, and a chemical examina- tion showed that this chert in all cases carries phosphoric acid in small amount. A thin bed of phosphate of lime was also found on the moun- tain in association with this chert.
The discovery of this phosphate rock was reported to the director of the Geological Survey of Canada and Mr. DeSchmidt was directed to make a detailed examination of the phosphate bearing horizon for the purpose of ascertaining whether beds of commercial value could be discovered. This gentleman had discovered two beds of which the larger was two feet in thickness, when his examination was brought to a close by the snowfall. The search, however, will be continued by the Geo- logical Survey of Canada next spring.