192 PLEISTOCENE OF INDIANA AND MICHIGAN. 



Portage River near its mouth. In western Jackson and eastern Calhoun counties the narrow 

 strips between the ridges of the Kalamazoo morainic system are sandy or gravelly and in part 

 swampy. 



The strip between the Kalamazoo and Charlotte morainic systems in Barry and Eaton 

 counties is gently undulating till of high fertility. In Calhoun County it is largely swampy, 

 including a swamp covering much of Lee Township. In southern Ingham County it includes 

 sand plains, large marshes, undulating till tracts, and a few sharp gravel ridges of esker type. 

 In places it so grades into the bordering moraine as to be difficult to delimit. 



The drift is of moderate thickness, 30 to 60 feet or less (aside from preglacial valleys), in 

 much of the district east of Battle Creek. West of that stream it is much thicker because of the 

 lower altitude of the rock surface, and in eastern Barry County it probably exceeds 150 feet. 



One occurrence of buried soil between drift sheets is known. A well on the farm of Mr. 

 Diebolt in the southwest part of sec. 25, T. 2 N., R. 6 W., in western Eaton County, penetrated 

 a black muck under till at 35 to 40 feet from the surface. Below the muck was a sand that 

 yielded water. Neighboring wells go down 75 to 100 feet and in one place 190 feet without 

 reaching rock, so it is probable, that this black muck is between the Wisconsin and Illinoian till 

 sheets. 



The most striking features of the tracts between the two morainic systems are the eskers 

 which occur both as long chains of gravel ridges and as isolated short ridges. 



RIVES ESKER CHAIN. 



The Rives chain of ridges is one of several that extend from the low plains near Lansing 

 up through the strong moraines to the south. Several of the eskers do not reach to the 

 Kalamazoo morainic system but terminate in the next later or Charlotte system. The Rives 

 esker system sets in at the south border of the Charlotte system and leads southward in 

 disjointed sections for about 16 miles, nearly to Jackson. Its southern portion, from Rives 

 Junction southward, was probably formed while the ice border was still holding its position 

 at the moraine in Jackson. Another section, which lies entirely north of Grand River, is likely 

 to have been formed after the ice border had shrunk back nearly to the line of Ingham and 

 Jackson counties. The third or northern section, which lies in the outer edge of the Charlotte 

 morainic system, may prove to be as young as that morainic system. The fact that these 

 esker ridges lie end to end in a nearly continuous esker trough is taken to indicate that they 

 have at least been formed in close succession by an essentially continuous subglacial stream. 

 It may seem remarkable that a subglacial stream should have maintained its track during so 

 great a recession of the ice border, but this is only one of several esker systems in southeastern 

 Michigan Avhich seem to require this interpretation. 



The southern section leads a little east of south from Rives Junction, nearly to Jackson, 

 a distance of about 7 miles. It lies in a swampy depression, one-eighth to one-fourth mile 

 in width, which is utilized by the Michigan Central Railroad and the Jackson-Lansing Electric 

 Line. The greater part of the esker is in view from the railway trams. Except for a mile or 

 so at the north end, which is strongly morainic, the district bordering the esker is a gently 

 undulating till plain, in which the esker terminates at the south without any gravel fan or 

 delta. However, a number of kames within a mile south of it in the northwestern part of 

 Jackson may perhaps be the product of the same stream which produced the esker. The 

 height of the esker ranges from 5 feet up to nearly 50 feet. Its highest part was in the village 

 of Rives Junction, but this has been removed for railway ballast. The esker seems to contain 

 a large amount of gravel suitable for railway ballast, but pits on its eastern slope near Rives 

 Junction contain also beds of sand. 



The middle section has its southern terminus directly across the valley of Grand River 

 about 1J miles northwest of Rives Junction and its northern end about 4 miles to the north 

 in sec. 24, Onondaga Township, Ingham County. It lies in sees. 24 and 25 and the north part 

 of sec. 36, in a swampy depression which extends a mile or more farther north than its north 

 eud. From the southeast part of sec. 36 southward to Grand River the esker lies on the slope 



