THE GLACIAL LAKE CHICAGO. 435 



Chicago ; otherwise they would have been obliterated by its waves. They 

 seem to oppose the view that a small lake held between the ice border and 

 the Valparaiso system had an elevation much greater than that of the sup- 

 posed upper beach of Lake Chicago. It seems not improbable that such a 

 lake may have stood 15 or 20 feet above that beach, but it scarcely could 

 have exceeded these limits. By combining the evidence from the St. Joseph 

 Valley and the wave-washed plain near Baroda, one is inclined to consider 

 the wave action displayed on that plain the product of a small lake held 

 between the ice and the Valparaiso system rather than a stage of Lake 

 Chicago higher than that which formed the well-defined beach on the inner 

 slope of Covert Ridge. 



There appears to have been a bay extending up the Pawpaw River 

 Valley at the highest stage of Lake Chicago nearly to the village of Hart- 

 ford. It appears not to have reached the site of that village since the low 

 plain bordering the river is found to carry well-defined basins several feet 

 in depth. One basin in the east part of the village occupies 5 or 6 acres 

 and has a depth of about 8 feet. Near Coloma wave action along the base 

 of the moraine, south of Pawpaw River, seems to have reached an altitude 

 about 650 feet above tide, or 70 feet above Lake Michigan. It has about 

 the same altitude immediately south of Watervliet. These lines of wave 

 action are only about 15 feet lower than the plain containing basins noted 

 at Hartford. 



There are a few exposures of gravel in St. Joseph at about 60 feet 

 above Lake Michigan, but from St. Joseph northward for several miles 

 Covert Ridge forms the bluff of the lake. Near the line of Berrien and 

 Van Buren counties it bears away from the lake, and beach deposits are 

 formed on its inner slope a mile or more west from the crest. They consist 

 largely of sand, there being only occasional small pebbles. It is not 

 possible, therefore, to determine so definitely as in southern Berrien County 

 the upper limits of the lake. The evidence, however, seems satisfactory 

 that the lake reached an elevation nearly 70 feet above the present level of 

 Lake Michigan. 



For a few miles north of South Haven, Covert Ridge again forms the 

 bluff of the lake and rises above the level of the upper beach, but in sec. 

 25, T. 1 N., R. 17 W., in Allegan County, exposures of gravelly sand were 

 found on its slope at about 60 feet above lake level. Gravel is reported to 



