Jan., 1908.] 
An Esker Group South of Dayton. 
2 33 
General Discussion of Eskers. Much question and dispute 
has arisen in the past concerning the terminology 5 for certain 
ridge-like products of glaciation, but the designation “Esker” 
is generally applied by American Geologists to lines of debris 
presumably aggraded by streams between walls of ice. Though 
the theory of deposition in sub-glacial tunnels 6 holds the greatest 
credence today, the en-glacial and super-glacial or various com¬ 
binations of the three theories have been offered as plausible 
explanations in specific instance. 7 For convenience this article 
assumes in the beginning that the Dayton ridges are eskers, and 
that they were formed in sub-glacial tunnels. 
Preliminary Description of Region. (Fig. 1.) The northern 
end is known locally as “The Bluff’s.” These trend east-north¬ 
east to west-southwest about half a mile presenting an abrupt 
slope considerably over one hundred feet high toward the valley 
of Dayton to the north. The Miami canal runs along the slope 
not far from its bottom, and below this at the base of the Bluffs 
flows the Great Miami River. The topography of this and also 
of the western half of the area presents a beautiful study in 
kames; mounds and basins 8 are abundant. The mounds or 
knolls frequently show a tendency toward alignment producing 
ridges. The eskers indicated on the map constitute the eastern 
boundary of this kame area. They overlie their base like rail¬ 
way embankments crossing uneven topography. 9 From the 
region of the Bluffs they proceed southward about a mile ending 
bluntly on the Miami Valley. The crest-lines are sinuous in both 
vertical and horizontal directions, though the general course is in 
almost a straight line. The esker form is at times modified by 
knolls, rarely by distinct gaps. The crests are narrow and the 
sloping sides steep, apparently taking the angle of repose normal 
to the debris of which they are composed. Both the eskers 
and the kamy topography westward rest upon a base rising above 
the valley of the Miami. To the southeast, across the road¬ 
way from the southern ends of the eskers the kamy topography 
continues for about a mile. This topography shows a curious 
branching and anastomosing of ridges. Though at present sug¬ 
gestive of kames it is quite possible that it represents modified 
glacial phenomena of other than kame origin. A more elaborate 
study of this will be made in a future paper. 
5. G. F. Wright, The Ice Age in North America, (1891), p. 296. 
G. H. Stone, Monograph XXXIV, U. S. Geol. Surv., (1899), pp. 35, 359. 
W. C. Morse, The Ohio Naturalist, Vol. VII, (1907), pp. 63-65. 
6. Chamberlin & Salisbury, Geology, (1906), Vol. Ill, pp. 373—7. 
7. W. M. Davis, Proc. Bos. Soc. Nat. Hist., Vol. XXV, (1892), pp. 477—99. 
J. B. Woodworth, Proc. Bos. Soc Nat. Hist., Vol. XXVI, (1894), pp. 197-220. 
O. H. Hershev, Am. Geol., Vol. XIX, (1897), pp. 197-209, 237-253. 
W. O. Crosby, Am. Geol., Vol. XXX, (1902), pp. 1-39. 
8. T. C. Chamberlin, loc. cit., p. 334. 
9. Chamberlin & Salisbury, loc. cit., p. 375. 
