194 PLEISTOCENE OF INDIANA AND MICHIGAN. 



lies about 2 miles south, in the east part of sec. 27, and wliich constitutes the southern end of the 

 section. The ridge has been opened for gravel in a few places and also for building sand, for it is 

 found to be sandy in places. The bedding, though usually horizontal, is in places sharply 

 inclined toward the south. 



The next section begins in the south part of sec. 27, whence a sharp ridge curves across the 

 northwest part of sec. 34 and ends in another fan. This seems to be the end of the chain, though 

 sandy and gravelly knolls west from its northern part in sees. 21 and 27, in a strong moraine 

 near Olivet village, may have been developed in connection with it. 



A capping of brown clayey and sandy gravel, 2 to 4 feet thick, covers the uneven and eroded 

 surfaces of beds of assorted material. Beds that contain but little sand are nearly horizontal, 

 but beds with much sand dip quite perceptibly toward the west, some of them 30° or more. 

 Scarcely any of the pebbles exceed 2 inches in diameter, and the great bulk of them are one- 

 half inch or less. Of 221 pebbles having a diameter one-fourth inch or less, 136 were sandstone, 

 limestone, and chert of local derivation; the remaining 85 were Archean, principally granites. 

 Of 52 fine pebbles having a diameter of one-fourth to one-half inch 30 were sandstone and lime- 

 stone of local derivation and 22 were Archean rocks, principally granites. Coarser pebbles are 

 principally sandstone but no count of them was made. No striated pebbles were observed, but 

 this is perhaps due to abrasion in the glacial stream. 



This chain of eskers' shows more clearly than is usual in eskers evidence of consecutive 

 northward extensions due to recession of the ice border. The tunnels in which the eskers were 

 formed apparently had a length of only 2 or 3 miles at the most. The apparent exclusion of 

 glacial drainage from the part of the Battle Creek valley in which the esker chain occurs is 

 difficult to explain unless stagnant ice masses persisted along this depression during the time 

 of the glacial drainage through the swamp leading past Olivet station. This drainage is dis- 

 cussed in connection with the Charlotte morainic system. 



SMALL ESKERS. 



Besides the esker chains above described minor ones are scattered through the moraine 

 in various situations. They consist of single ridges a fraction of a mile in length that are either 

 isolated or are very remotely connected with other eskers. One was noticed in the Grand 

 River Valley about 2 miles north of Onondaga. Several small eskers occur in the valleys of the 

 north tributaries of Portage River in northern Jackson and southern Ingham counties. 



OUT WASH. 



DISTRIBUTION AND CHARACTER. 



The outwash plains on the border of the Kalamazoo morainic system of the Saginaw lobe 

 are among the most conspicuous in Michigan. They are extensive in the reentrant angles 

 between the Lake Michigan and Saginaw lobes and the Saginaw and Huron-Erie lobes, and also 

 along the front of the Saginaw lobe from the meridian of Kalamazoo eastward to the meridian 

 of Marshall, and from Jackson eastward to the Huron-Erie reentrant. Between Jackson and 

 Marshall there are channels formed by the glacial drainage along or near the ice border. The 

 entire system of outwash aprons and channels found discharge southward along the eastern 

 edge of the Lake Michigan lobe to the St. Joseph Valley near Three Rivers, and thence past 

 South Bend to the Kankakee, from which, as now, the drainage led to Illinois and Mississippi 

 rivers and the Gulf of Mexico. 



The outwash aprons are throughout indented by numerous basins, some 2 or 3 square miles 

 or more in extent, but the majority only a fraction of a square mile. Many of them are 20 to 30 

 and some 50 to 60 feet deep. As a whole they occupy nearly as much area as the flat parts 

 of the outwash. On their slopes and beds some bowlders and many sharp hummocks 

 are found. To the eye the basins appear to be morainic, but they are probably due to the 

 presence of masses of stagnant ice during the building up of the outwash plains around them. 



