THE LAKE-BORDER MORAINIC SYSTEM. 395 



It is probable that the upper 25 feet of this section is a deposit made 

 in water, and possibly also the lower portion was deposited under similar 

 conditions. As a talus obscures the lower portion of the bluff in places 

 between these two sections, the exact equivalency of the beds at the base 

 of the sections can not be established. 



North of St. Joseph there are exposures along the shore of the lake in 

 which large masses of cemented gravel and sand are interbedded with the 

 blue till. This is apparently a local feature. The till here, as in the 

 exposures near New Buffalo, shows traces of lamination and is scarcely so 

 pebbly as typical till. An exposure west of Hagar Station, at a point where 

 the lake bluff is cut back nearly to the crest of Covert Ridge, shows the 

 following series of beds: 



Section near Hagar, Berrien County, Michigan. 



Feet. 



Sand, varying from a few inches to several feet 1-8 



Yellow till, thickest where sand is thin 1-5 



Blue till, not very stony 30 



Sand, variable in coarseness, with thin clay beds 20 



Blue-gray till, quite stony 50 



Total 110 



An exposure in sec. 18, T. 2 N., R. 17 W., shows a laminated clay at 

 the base of the surface sand which may be referable to the glacial lake, 

 though it seems more probable that it was deposited beneath the ice sheet. 

 The section of the lake bluff is as follows: 



Section of bluff of Lake Michigan in see. 18, T. 2 N., R. 17 W. 



Feet. 



Sand 4-8 



Laminated gray clay, slightly pebbly 12 



Sand and gravel 3 



Blue-gray till, quite stony 15 



Total 36 



Several sections of wells were obtained in each of the counties traversed 

 by these ridges, which throw light upon the structure of the drift to con- 

 siderable depth. In a few cases the entire drift series has been pene- 

 trated. In presenting these well sections the discussion begins in Porter 

 County, Indiana, and counties are taken up in succession toward the 

 northeast. 



