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Till on Overthrust Gravels
Published online by Cambridge University Press: 01 May 2009
Extract
The Plate which accompanies this article, showing till over-riding and overthrusting in its readvance the gravels on which the yard of Harvard University is built, is of a temporary exposure. This was made in putting in a large apartment house at the north-west corner of Arlington Street and Massachusetts Avenue, North Cambridge. The camera was pointed north. Realizing its ususal character, I got my colleague, Prefessor M. S. Munro, who is a virtuoso with the camera, to take it, and have used it as a postcard to friends. One of them, my old teacher, William Morris Davis, said it was unexcelled, and urged its publication. That is the occasion of this article, for, when I came to think of it, to obtain such a photograph required an unusual combination of circumstances:—
(1) The artificial excavation;
(2) A strike that suspended work at the critical time (it is an ill wind that blows no one good);
(3) Just such conditions of wind and drying out as to bring out the different beds in the sands. The coarser ones dry and crumble more rapidly, while the fine hold the dampness and stand out. We might add:—
(4) A man living on the street (myself) to appreciate it, and
(5) A friend who is an excellent photographer.
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References
page 9 note 1 Professor Charlesworth, J. K., ”: Geol. Mag., Vol. LXIV, 04, 1927, pp. 157–63. See also P1. IX of K. E. Williams' article on the glacial drifts of Western Cardiganshire, May, 1927, pp. 205–26.CrossRefGoogle Scholar
page 9 note 2 Seventh Report, Michigan Acad. of Sci., 1905, p. 37;Google Scholar see also Bull. Geol. Soc. Am., 16, 1906, pp. 577–8, and 17, 1907, p. 707;Google Scholar Am. Geologist, 35, 1905, pp. 177–9;Google Scholar Science, 21, 1905, pp. 220–1;Google Scholar Scientific Am. Suppl., 59, 1905, 24326;CrossRefGoogle Scholar Mich. Geol. Sur. Report, 1904, pp. 33–112, and 1906, pp. 7–91.Google Scholar
page 9 note 3 Bull. Geol. Soc. Am., 16, 1906, p. 577.Google Scholar
page 9 note 4 Seventeenth Ann. Rep. of the U.S. Geol. Surv., 1896, pt. i, a paper with N. S. Shaler and C. F. Marbut on the glacial brick clays of Rhode Island and South-Eastern Massachusetts, especially chap. iii, figs. 42 and 43, and pp. 995 to 997.Google Scholar
page 10 note 1 Loc. cit.
page 10 note 2 Loc. cit., p. 160.
page 10 note 3 Antevs, E., “The recession of the last ice sheet in New England”: Am. Geographical Society, Research Ser. No. 11, New York City, pp. 3 and 7 as to salt water, pp. 77 to 81 as to readvance.Google Scholar
page 10 note 4 Bull. Geol. Soc. Am., 33, 1922, P. 356;Google Scholar see also Lefax 13–18, Table for the recognition of Minerals, xviii, and Melcher, A. F., Trans. A.I.M.E., lxv, 1921, p. 470.Google Scholar
page 11 note 1 Antevs, Cf. E., Retreat of the last Ice-sheet in Eastern Canada, Memoir 146 of the Geol. Survey of Canada (1925), p. 90 and before and after.CrossRefGoogle Scholar