Biennial report of the Board of Regents of the University of Minnesota, to the Governor

by University of Minnesota

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1890 edition. ...place where the current of Ste. Marie's river meets the slack-water of lake Huron and extending for several miles, the knobs are composed of compact greenstone, occasionally partaking of a sub-slaty character, and under which circumstances, the rock bears a close analogy to some of the varieties of primary argillite." "On the northern part of the island of St. Joseph, a fraction of the southeastern part of Sugar island, and a portion of the main land on the east, the place of the hornblende rock is supplied by granular quartz rock, usually white, but sometimes passing to a reddish or deep red color." "In the range of hills bounding the easterly side of Great Lake George, talcose slate was observed, but to what extent it exists I am unable to say" (p. 13). It appears that Dr. Houghton's conception of "Primary rocks" was rather broad. The granular quartz rock mentioned is now known to be a westward extension of the "Huronian" quartzites of the Thessalon valley in Canada. The "talcose slate " on the other hand, probably belongs to the Marquette iron-bearing series which by the present writer has been suggested to be an older system than the Huronian. It is worthy of note also, that Dr. Houghton repcrts the " Lake Superior sandstone" as resting " against and upon the Primary range of the Ste. Marie's river." That is, at one point the "talcose slates" (Marquette series) rest in contact with the gneisses; at another, the overlying quartzyte (Huronian) extends over to the gneiss; and at another, tbe still higher sandstone (Palaeozoic) reaches over to the gneiss. Thus, it is unsafe to conclude that the formation resting on the gneiss at any particular spot is the...

144 pages, Paperback

Published September 13, 2013