DEPOSITS OF THE LAKE CHICAGO BASIN 



55 



B. SOUTH OF JACKSON PARK 



It is reported 1 that a ledge of rock, 300 or 400 feet in width, extends a short 

 distance west of Yates Avenue, north of 75th Street. The rock here does not 

 show at the surface, but on Kingston Avenue, about one-half block north of 

 75th Street, there is a small outcropping. 



On the corner of 75th Street and Jeffery Avenue, about five feet beneath 

 the surface, a sand and gravel deposit occurs, in which the following mollusks 

 were found by Mr. Ira Meyers, of the Francis Parker School, Chicago: 



Alasmidonta calceola 

 Sphaerium striatinum 

 Pisidium virginicum 



compression confertum? 

 " superius' 



" (resembling mainense, but 

 apparently distinct) 

 Galba catascopium 



Physa Integra 



Valvata bicarinata perdepressa 

 Goniobasis livescens 

 Amnicola lustrica 



" emarginata 



" letsoni 

 Somato gyrus integer 



The sand and shells were evidently washed behind the submerged limestone 

 barrier which outcrops on Kingston Avenue, and is about 585 feet above sea 

 level or 5 feet above the lake. 



C. SOUTH OF CALUMET LAKE 



South of Calumet Lake {130th Street) and east of Michigan Central Railroad 

 Surface 585 feet A.T.; 5 feet A.L.M. Unio beds beneath Indian graves* 



Fusconaja undata 

 Quadrula pustulosa 

 Elliptio gibbosus 



Eurynia recta 

 Lampsilis ventricosa 

 Goniobasis livescens 



D. NEAR LEMONT 



Lincoln Park property, Lemont, near Santa Fe Railroad {Section 16, Dti Page County). Surface 



595 feet A.T.15 feet A.L.M 



Strata 



Deposit 



Depth 



Remarks 



V 



Black carbonaceous loam 



36 



26 



12 



9 



+ 



83 



With plant remains 



rv 



Black carbonaceous soil 



in 



Peat bed 



With shells. 



n 



Marl and silt bed 





i 



Niagara limestone 







Total thickness.... 





1 By Mr. D. W. Roper, of the Chicago Telephone Company. 



2 Collected by Mr. A. Scharf. 



