124 PLEISTOCENE OE INDIANA AND MICHIGAN. 



The name "shoulder" might be more appropriate. With further recession into Michigan, 

 however, reentrant angles developed between it and the Lake Michigan lobe on the one hand, 

 and between it and the Huron-Erie lobe on the other, and the application of the term "lobe" 

 becomes fitting. For a time the southern part of the Huron basin and the Erie basin held 

 but a single lobe, the Huron-Erie, which later separated into two lobes, the Huron and the Erie. 

 The differentiation just suggested is the simplest possible. The actual history may have 

 been more complicated. The border of the lobes, for instance, may have readvanced instead 

 of merely halting at the moraines formed during the recession; complications of this sort, 

 however, are not as yet sufficiently worked out to justify presentation. In the ensuing dis- 

 cussion the reentrant district between the Saginaw and Michigan lobes will first be considered, 

 and then the several moraines — Maxinkuckee, New Paris, Middlebury, Lagrange, Sturgis, and 

 Tekonsha — formed during the withdrawal of the Saginaw part of the ice sheet northeastward 

 into Michigan will be taken up. 



REENTRANT DISTRICT. 



NEBO-GILBOA RIDGE. 



In 1859 attention was called to the Nebo-Gilboa ridge by Richard Owen, 1 who termed 

 two of its prominent knolls Mount Nebo and Mount Gilboa. Notwithstanding the appellation 

 "mount" to these knolls (neither much exceeds 50 feet in height) the ridge is one of the smallest 

 moraines in the State, its width averaging scarcely one-fourth mile and its height about 25 feet. 



Throughout Benton County, Ind., the Nebo-Gilboa ridge constitutes the divide between 

 the Illinois and Wabash drainage basins, but in White County it passes into the basin of the 

 Wabash. It has a length of fully 30 miles and fades out in a plain 3 miles northwest of Brooks- 

 ton, Ind. A bowldery strip just south of the eastern end of the ridge, and possibly a dependency 

 of it, continues eastward past Brookston to the Tippecanoe Valley, and there connects some- 

 what loosely with the Chalmers kame belt. In its western half the ridge reaches a little above 

 800 feet above sea level, and Mount Nebo and Mount Gilboa probably reach 850 feet. In its 

 eastern half it gradually descends to about 700 feet. Its surface is gently undulating and it 

 shows a definite crest along nearly its entire length. 



The wells on the ridge are mainly through clayey till. Considerable till was found in a 

 well on Mount Nebo, though parts of the knoll are sandy. Mount Gilboa seems to be composed 

 largely of sandy gravel. These two knolls are to be classed as kames. Along the ridge bowlders 

 are common but are not more conspicuous than on parts of the bordering plain. 



At the time Monograph XXXVIII was written a ridge in eastern Iroquois County, Til., 

 now believed to be a continuation of the Nebo-Gilboa ridge, was supposed to be older 2 because 

 of its position west of the great bowlder belt that was thought to mark the limits of the later 

 Wisconsin drift. The bowlder belt, however, more nearly coincides with the border of the Lake 

 Michigan lobe in the reentrant angle between the Lake Michigan and Saginaw lobes than it does 

 in its passage over theBloomington morainic system to the south. The ridge west of the bowlder 

 belt and reentrant angle is a moraine of the Lake Michigan lobe, and the Nebo-Gilboa ridge 

 is thought to be a correlative moraine formed by ice farther east which later became differentiated 

 into the Saginaw and Huron-Erie lobes. The village of Earl Park, Ind., stands near the place 

 of intersection. 



CHALMERS KAME BELT. 



The Chalmers belt is best developed within 4 miles east, northeast, and southeast of the 

 village of Chalmers, in White County, Ind., but its kames are scattered over the plain from 

 Chalmers to Tippecanoe River and from near Monticello to the Wabash Valley southeast of 

 Brookston and a few are east of Tippecanoe River near Monticello. The knolls are sharp and 

 rather closely aggregated near Chalmers, but near the Tippecanoe are separated by flat tracts of 

 considerable extent. The highest knolls rise 50 to 60 feet above the bordering plains, and 



i Ann. Rept. Indiana Geol. Survey for 1859, 1860, p. 219. 



2 The Illinois glacial lobe: Mon. U. S. Geol. Survey, vol. 38, 1899, p. 258. 



