432 THE ILLINOIS GLACIAL LOBE. 



ward from near Wheeler to the south border of the sand belt near Chrisman. 

 From Salt Creek Basin a bay or marsh extended up Calumet River, prob- 

 ably about to the east line of Porter County, a distance of 10 miles or 

 more. Its connection with the open lake appears to have been along the 

 line of Calumet River. In this bay and also the one in the Deep River 

 Basin wave action was not strong enough to form continuous well-defined 

 shores, yet cut banks 3 or 4 feet in height were noted at several places on 

 their borders, and there is a thin coating- of sand over much of the area 

 covered by the bays. East of Hobart the sand presents low ridges 5 to 10 

 feet high and 10 or 12 rods wide, trending nearly north to south. These 

 are developed only over 1 or 2 square miles. 



A bay also occupied east and west Trail Creek valleys and connected 

 with the open lake along the valley of the main Trail Creek. This bay 

 was shut off from the main water by the till ridges which follow the north 

 side of these streams. Its outlet into the lake is bordered in places by a 

 sandy ridge running northward parallel with Trail Creek. The best 

 developed ridge is on the west side of the creek, in sees. 11, 2, and 3, 

 T. 37, R. 4 W., where it has a height of 10 or 12 feet and is maintained for 

 a distance of 2 or 3 miles. There is a deposit of sand several feet in depth 

 covering the bottom of this bay. It may have been derived in large part 

 as a wash from the steep bluff-like border of the Valparaiso moraine, which 

 lies immediately south. 



From the valley of Trail Creek, near Michigan City, Indiana, north- 

 eastward to Gralien River near New Buffalo, Michigan, a distance of 6 or 7 

 miles, it is difficult to locate the upper beach. There are several short 

 sandy ridges separated by swamps and marshes, but not a continuous well- 

 defined belt of sand, such as is developed farther west. In some cases the 

 sand ridges are evidently wind-drifted, and probably they are largely 

 modified by wind. They occur not only on the slope between Covert till 

 ridge and Lake Michigan, but also along the crest of that ridge, reaching 

 an altitude 75 feet or more above Lake Michigan. In a few places gravel 

 deposits were noted on the inner slope of the till ridge at an altitude as 

 high as 30 feet above the lake. They are well displayed along the main 

 street in New Buffalo leading southwest from the post-office. There is also 

 a good exposure southeast of the Methodist church, the depth of gravel 

 being several feet. In the vicinity of the public school building there are 





