Biennial Report - State Geological Survey of North Dakota Volume 5 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...holds this height quite uniformly northward to the Pembina river, in the south part of township 163, R. 57, about five miles south of the international boundary. It is a prominent wooded bluff, some 300 feet high, extending in a very direct course from south to north or a few degrees west of north. From its southern end to the Pembina river the base of this escarpment is 1,200 to 1,225 feet above sea level. The width occupied by its slope varies from a half mile to two or three miles, and from its crest a treeless plateau, having a moderately rolling surface, stretches with slow ascent westward. North of the Pembina river its crest sinks to about 1,400 feet, and its base to about 1.025 feet at the international boundary. Where the Pembina river cuts through this escarpment, entering the area of Lake Agassiz, the eroded eastern front of its delta deposit forms another conspicuous bluff, about 200 feet high, falling in a steep, wooded slope from 1,175 to 975 feet, approximately, above the sea level. The delta b'uff, cilled the "First Pembina Mountain," is composd of sand and gravel, and lies about five miles east of this more prolonged line of highland, which is known in that vicinity as the "Second Pembina Mountain." The latter, throughout its entire extent both in North Dakota and Manitoba, is caused by the outcrop of a continuous bolt of almost level Cretaceous strata, mostly overspread by glacial drift. (See Plate XX.) The ascent of this highland on the international boundary, where it occupies a width of about one and a half miles, is described by Dr. G. M. Dawson as follows: "The eastern front of the Pembina escarpment is very distinctly terraced, and the summit of the plateau, even at its eastern edge, thickly covered with drif...