443 THE ILLINOIS GLACIAL LOBE. 



the bay back of it. Mr. W. C. Alden has found slight traces of the beach 

 in the west part of Chicago. 1 This bar lies within a mile of the present 

 shore of Lake Michigan and is readily traced as far south as Lincoln Park. 

 The bar is said to have been nearly continuous through the city of Chi- 

 cago, but in grading up the business portion of the city it has been oblit- 

 erated from Lincoln Park southward nearly to the Douglas Monument, and 

 the writer has been unable to obtain a map or other accurate data showing 

 its former extent. The bar is preserved from the Douglas Monument 

 southward to Englewood, a distance of 4 or 5 miles. This portion consists 

 of a series of overlapping ridges, of Avhich the westernmost or earlier ter- 

 minate farther north than their successors on the east. At the termination 

 of each of these ridges a hook turns out to the west into the bay that stood 

 west of the bar. An outlet seems to have been maintained toward the Des 

 Plaines around the southern end of this advancing bar, until it reached 

 Englewood. This may not have been closed until the water level had 

 dropped too low for a discharge to the Des Plaines. It formed a well- 

 defined gravelly shore in its north border from the Hawthorn cpiarry west- 

 ward to Riverside, as determined by Mr. Alden. Upon passing across the 

 outlet marsh from Englewood to South Lynne one finds a continuation of the 

 Tolleston beach, which leads northwestward to the Des Plaines at Summit. 

 From South Lynne it leads in a course east of south to South Englewood 

 and thence more nearly east across the northwest corner of Calumet Town- 

 ship into Hyde Park, coming to the Illinois Central Railway a short distance 

 north of Pullman. From this point a gravelly ridge is traceable southward 

 past the north border of Lake Calumet, where it dies out in the marsh. A 

 slight beach is formed to the northeast from here on Stony Island, between 

 Lake Calumet and South Chicago. But the main line of this beach is 

 found west of Lake Calumet, running north and south through the west 

 parts of Pullman and Kensington, where it usually has the form of a cut 

 bank 10 to 15 feet in height, but changes to a gravelly and sandy beach at 

 the south. This beach comes to the Calumet River at Riverdale, where it 

 connects with the Sag outlet. It reappears on the south side of the river 

 at Dolton and passes thence southeastward into Indiana. 



1 Mr. Alden has made a thorough mapping of the surface deposits of the Chicago and Calumet 

 quadrangles for this Survey. 



