POET HTJKON MORAINIC SYSTEM AND PROBABLE COKKELATIVES. 307 



Several short eskers were noted in the reconnaissance made on the Huron slope in Che- 

 boygan, Presque Isle, and Alpena counties. With the exception of one in central Alpena 

 County, which is about 10 miles in length, none were observed which exceed 3 miles. It is 

 not improbable, however, that the mapping of eskers is incomplete; it is difficult to trace such 

 small ridges through forested areas, and the lines traversed by the writer were at such wide 

 intervals that eskers might easily be present in the intervening tracts without being observed. 



The esker in central Alpena County sets in at Thunder Bay River about 2 miles east of 

 Long Rapids and runs southward through T. 31 N., R. 6 E. For a couple of miles at the north- 

 ern end it has considerable complexity, there being in places three ridges side by side. It shows 

 also a plexus of ridges in sees. 2 and 11, T. 30 N., R. 6 E. Its highest part is in sees. 2, 10, 

 and 11, T. 30 N., R. 6 E., where points stand 50 to 75 feet above the bordering plain; but its 

 ordinary height is about 25 feet. It trends west of south and terminates in the northern end 

 of a great morainic tract which crosses southwestern Alpena County. This trend differs from 

 that of the drumlins to the east, which bear north-northwest and south-southeast, but it nearly 

 agrees with that of two drumlinoidal hills to the west. It seems not unlikely, therefore, that 

 the esker represents the direction of the ice movement in the district which it traverses. Its 

 northern portion has been opened at several places for gravel, which is found suitable for road 

 ballast. Its southern end is somewhat more sandy and is less extensively opened. 



An esker about 3 miles in length leads southward from La Roque station on the Detroit & 

 Mackinac Railway through sec. 31, T. 34 N., R. 5 E., and sees. 6 and 7, T. 33 N., R. 5 E., its 

 course being 20° to 25° east of south. It is a nearly continuous, very sharp ridge, about 30 

 feet in height, composed of fine gravel apparently suitable for road ballast. 



About 5 miles west of La Roque a very prominent gravelly ridge is crossed by the Detroit 

 & Mackinac Railway in a cut nearly 75 feet deep. This ridge is more massive than the ordinary 

 esker and has an irregular surface much like a moraine, but seems to be composed almost entirely 

 of gravel and sand. It runs southward from the railway about 3 miles along the east side of 

 Oqueoc River and occupies a width of about one-half mile. Farther south a rolling gravelly 

 belt of still greater width leads through the western part of T. 33 N., R. 4 E., with a trend very 

 nearly the same as that of the La Roque esker. It may therefore mark the course of sub- 

 glacial drainage as an esker does. 



Some small eskers cross the State road from Onaway about 8 miles west of that village in 

 the northeast part of T. 34 N., R. 1 W. The easternmost runs a little east of south through the 

 SW. i sec. 1. West of it a very prominent esker with similar trend was traced northward 

 a little beyond the township line from sec. 2 into sec. 35. Possibly both eskers are continued 

 beyond the limits noted. 



DRUMLINS. 



Two widely separated drumlin areas lie on the Huron slope, one being east of Mullet Lake 

 in Cheboygan County and the other 50 to 60 miles to the southeast in central Alpena County. 

 None were noted in the intervening district, but as it is a forested region and was not closely 

 traversed, some may yet be discovered. 



The drumlins east of Mullet Lake are in sees. 4, 5, 8, 9, 15, 16, 21, 22, 23, and 27, T. 36 N., 

 R. 1 W., opposite the northern part of the lake. They are only 15 to 20 feet in height, less than 

 a mile in length, and but one-eighth to one-fourth mile in width. They trend northwest and 

 southeast, or nearly parallel to the neighboring morainic ridges. They are in a low tract con- 

 siderably below the level of Lake Algonquin and must have been covered by the waters of that 

 lake after the ice had receded from this region. They are composed of a stiff clayey till, and 

 their surface, as well as that of the intervening sags, is thickly strewn with bowlders, which 

 seem to have been deposited during the recession of the ice, being confined chiefly to tracts in 

 which till is at the surface and being very scarce on the sandy tracts. 



The other drumlin area lies a few miles west of Alpena, in central Alpena County, in a till 

 plain west of the south branch of Thunder Bay River, at a level slightly above that of the highest 



