174 SURFACE GEOLOGY. 



higher than now, from which level it sank to its present height, or lower ; 

 but no well marked beach-ridges have been discovered inland. 



Review of the Champlain and Terrace Periods in New Hamp- 

 shire. 



The CJiamplam period embraces the time occupied by the final melt- 

 ing of the great ice-sheet. At first its nearly level surface of pure ice 

 lay above our highest mountain summits. As the melting advanced, it 

 was moulded into basins and valleys, which, near the terminal front of 

 the ice, coincided nearly with the contour of the land. At last the sur- 

 face of the ice became covered with the abraded material which had been 

 contained in its mass. A large part of this material was washed away 

 by its streams, to be deposited in the modified forms of kames,* kame- 

 like plains, and valley drift. Through the whole of every summer during 



* Since writing the first part of this chapter, I have learned that, as early as in 1872, Prof. N. H. Winchell, state 

 geologist of Minnesota, had been led by his observations of kames in Ohio and Minnesota to an opinion respect- 

 ing their formation similar to that presented in pp. 12-14, which, when first announced in August, 1876, was sup- 

 posed to be entirely new. (See citations below, under Ohio and Minnesota.) 



For the benefit of those who may be interested in this subject, and may wish to see descriptions of these depos- 

 its elsewhere, we append the following list of authors who have treated, more or less fully, of kames : 



Canada. Principal J. W. Dawson, Notes on the Post-Pliocene Geology of Catiada, 1872, pp. 26, 40, 107, and 

 112; Acadian Geology, 1868, pp. 82 and 324. Geological Survey of Canada; Report of Progress for 1870-71, 

 p. 349 (Robert Bell) ; do. for 1875-76, pp. 262 (G. M. Dawson) and 340 (Robert Bell). 



Maine. Prof C. H. Hitchcock, Agriculture and Geology of Maine, 1861, pp. 271-274; do., 1862, pp. 388-391. 

 Prof. L. Agassiz, Atlantic Monthly, vol. xix , February, 1867, pp. 213-215. 



New Hampshire. Dr. Edward Hitchcock, Transactions of the Association of American Geologists and 

 Naturalists, 1840-42, p. 198, Plate viii; also, Smithsonian Contributions, vol. ix, 1857, pp. 36 and 45. Warren 

 Upham, Proceedings of American Association for Advancement of Science, vol. xxv, 1876, pp. 216-225. 



Vermont. Prof. C. H. Hitchcock, in Geology of Vermofti, vol. i, 1861, pp. 95, 102, 150-152, and 190. 



Massachusetts. Dr. Edward Hitchcock, Geology of Massachusetts, 1841, pp. 356 (Figs. 62 and 65) and 366- 

 370; Transactions of the Association of American Geologists and Naturalists, 1840-42, pp. 190-203, and Plates 

 viii and ix ; and Smithsonian Contributions, vol. ix, 1857, p. 44 (lowest paragraph). Rev. George F. Wright, 

 Proceedings of Boston Society of Natural History, vol. xix, 1876, pp. 47-63- 



Connecticut. Prof James D. Dana, Transactions of the Connecticut Academy of Arts and Sciences, vol. ii, 

 1870, pp. 70 and 71. 



New York. Geology of New York, Second District, E. Emmons, 1842, pp. 186, 323, 333, and 364; do., Third 

 District, L. Vanuxcm, 1842, p. 247. In this and other states bordering the great lakes, ridges of sand and gravel 

 are found, which must be distinguished from the kames, being apparently ancient beach-ridges, formed when these 

 lakes were held at higher levels during the Champlain period. Their present outlet through the St. Lawrence 

 valley was obstructed by the ice-sheet, which seems here to have retreated from south-west to north-east. 



Ohio. Dr. J. S. Newberry, Geology of Ohio, vol. ii, 1874, pp. 7, and 41-46. Prof. N. H. Winchell, Proceed- 

 ings of American Association for Advancement of Science, vol. xxi, 1872, p. 165. 



Michigan. E. Desor, in Foster and Whitney's Report on Geology of Lake Superior, 1850, pp. 196 and 205; 

 do., part ii, 1851, p. 258. 



Minnesota. Prof. N. H. Winchell, Geology of Minnesota, First Annual Report (for 1872) p. 62, etc. ; Report 

 for 1873, p. 194, etc. 



Ireland. G. H. Kinahan, Geological Magazine, new series, vol. i, 1864, pp. 34, 89, and 189 ; do.. Decade ii, 

 vol. ii, 1875, pp. 86 and 87. 



Scotland. James Geikie, Great Ice Age, 1874, American edition, pp. 209-237; do,, second edition, revised; 

 London : 1877, pp. 210-252. 



Sweden. James Geikie, Great Ice Age, 1874, American edition, pp. 357-367; do., second edition, revised, pp. 

 407-416. 



