282 PLEISTOCENE OF INDIANA AND MICHIGAN. 



At Romeo the 400 or 500 yard Alrnont channel passes into the mile-wide Rochester chan- 

 nel west or in front of the strong, high morainic ridge which begins at Romeo and extends 

 south-southwestward, past Rochester and Birmingham, opening out at the latter place upon 

 the lake plain below the highest beach of Lake Maumee. 



The Birmingham moraine from Romeo to a point about 3 miles northeast of Rochester 

 is a high, relatively narrow ridge of bowlder clay and is in fact one of the most sharply developed 

 and clearly defined terminal moraines in this region. 1 Beyond this point the strongly developed 

 ridge ends and is replaced by a small till plain, and where the moraine reappears south of the 

 Clinton River it is relatively low and smooth. South of sec. 22, Avon Township, Oakland 

 County, to Birmingham its crest steadily falls, gradually losing its expression as a land-laid 

 moraine. It continues, however, 6 or 7 miles southwest from Birmingham as a low, smooth 

 swell which controls the course of Rouge River. At Birmingham it merges with the north end 

 of a much broader low ridge, probably interlobate in character, which runs southeastward 

 directly down the slope to Detroit and thence southeastward nearly to the shore of Lake Erie 

 at Leamington, Ontario. The continuation of its Lake Erie correlative in Wayne and Monroe 

 counties as a water-laid moraine 2 and bowldery strip will be discussed later (pp. 287-289). 



TOPOGRAPHY. 



ALTITUDE AND BELIEF. 



At Imlay the Birmingham moraine, or rather the bowldery strip which represents its faint 

 development, has an altitude of 860 to 880 feet. Thence southward to Almont it declines at 

 about the same rate as the highest beach of Lake Maumee, and in the south part of Almont it 

 has an altitude of about 845 feet. Only the large knoll northeast of the village rises much above 

 the beach, attaining an altitude of 865 to 870 feet. From Almont south to Clinton River north of 

 Romeo the moraine is very low, being in places slightly above the level of the beach and in 

 places slightly below it. The altitude of the beach at Romeo is about 830 feet. 



At Romeo the moraine suddenly becomes strongly developed, though not more than 1£ 

 miles wide, and continues so to a point 3 miles northeast of Rochester, its crest rising in several 

 places above 900 feet and having an average elevation of about 870 feet. A till plain of about a 

 square mile with an altitude of 760 to 780 feet there takes the place of the moraine. South of 

 Rochester in a small area in sec. 22, Avon Township, the crest rises to an altitude a little abovo 

 860 feet; beyond, it declines steadily at the rate of about 10 feet to the mile to an altitude of 

 780 feet at Birmingham. 



From Imlay to Romeo the Birmingham moraine has extremely slight relief, few of its knolls 

 rising more than 10 or 15 feet above the adjacent ground. At Romeo and southward it has a 

 steep slope on both its sides and rises 60 to 1 00 feet above its base. South of Rochester it has a 

 relief of 60 or 70 feet, but declines rapidly toward Birmingham.. 



CHARACTER. 



From Imlay to Romeo the moraine generally consists of low bowldery knolls, with some 

 small kames and gravel ridges. For much of the distance the crest is only a little above the 

 highest beach of Lake Maumee, and toward Romeo it at some places passes below the beach level, 

 the beach appearing only on small islands. 



From Romeo to Rochester the strong moraine has a sweU and sag topography, with some 

 basins where its slopes have not been subsequently modified. Its eastern slope, however, was 

 heavily undercut after it was made and has since been deeply gashed with ravines. For 3 or 

 4 miles south of Rochester the ridge has a faint swell and sag expression, but within a short 

 distance farther south it becomes smooth and devoid of notable surface features. 



1 See Rochester topographic sheet of the U. S. Geol, Survey. 



* In 1913 Leverett and Sherzer found evidence of the continuation of the moraine in water-laid form along the east side of Rouge River to the 

 Wayne County line. There are slight undulations on its southeastern or inner slope, and the relief on that side is in places easily perceptible to 

 the eye, being 15 feet or more in half a mile. 



