DEPOSITS OF THE LAKE CHICAGO BASIN 



47 



station 44 (Plate XXI) 

 500 feet south of Dempster Street. Surface 595 feet A.T.; l5feetA.L.M. 



Strata 



Deposit 



Depth 



Remarks 



VI 



Silt and loam 



30 



5 



36 

 10 

 60 



84 



225 



With shells. 



V 

 IV 



Sand and gravel; few boulders.... 

 Blue clay 



This deposit lies from 30 to 40 

 inches below the surface, and 

 varies from 2 to 6 inches in 

 thickness. 



With rootlets. 



in 

 ii 



Brownish-yellow sandy clay 



Laminated blue clay 



See rule in photograph. 



i 



Boulder clay 







Total thickness.... 





station 45 (Plate XXII) 

 200 feet south of Dempster Street. Surface 595 feet A.T.; 15 feet A.L.M. 



Strata 



rv 



ni 



ii 



i 



Deposit 



Silt and loam 



Sand and gravel 



Blue clay 



Laminated clay 



Boulder clay 



Total thickness 



Depth 



33 



2 



30 



30 



132 



227 



Remarks 



Shells begin 12 inches below the 



surface. 

 In places nearby 3 inches. 

 With rootlets. 



BIOLOGICAL REMAINS 



Stratum V 



Musculium truncatum 

 Pisidium affine 

 Physa gyrina 

 Planorbis trivolvis 



Segmcntina armigera 

 Galba caperata 



" reflexa 

 Succinea retusa 



