ILLUSTRATIONS 



PLATE , FACING PAGE 



I. Map showing Distribution of Potomac Deposits in Maryland 23 



II. Fig. 1. — View showing basal conglomerate of the Patuxent over- 

 lying the Piedmont Crystallines at Roland Park, Baltimore City 32 

 Fig. 2. — :'View showing Patuxent arkosic sands and gravel in B. & 

 O. R. R. cut at Savage, Anne Arundel County 32 



III. Fig. 1. — ^View showing coarse, highly inclined and cross-bedded 



Patuxent sands near Homestead, Baltimore City 40 



Fig. 2. — View showing kaolin in the Patuxent formation in cut on 

 P. B. & W. R. R. near Perryville, Cecil County 40 



IV. Fig. 1. — View showing eroded upper surface of the Patuxent over- 



lain by Sunderland deposits. Belt Line cut near Charles Street, 



Baltimore City 60 



Fig. 2. — View showing Patuxent- Arundel contact south shore of 

 Spring Gardens, the probable locality where Tyson collected 

 the historic Johns Hopkins cycad stump, Baltimore County. ... 60 

 V. Fig. 1. — View showing indurated ledges in the Patuxent formation, 



W Street near 12th Street, Washington, D. C 64 



Fig. 2. — ^View showing flooded iron mine in the Arundel formation 



near Muirkirk, Prince George's County 64 



VI. Fig. 1. — ^View showing the Patuxent-Arundel contact in Belt Line 



cut near the eastern boundary of Baltimore City 68 



Fig. 2. — View showing erosion of old iron mine in the Arundel 



formation, Schoolhouse Hill, Baltimore County 68 



VII. Fig. 1. — ^View showing erosion of Arundel clays, Hartke Iron Mine 



near Hanover, Howard County 72 



Fig. 2. — View showing Reynolds Iron Mine in the Arundel forma- 

 tion 1 mile south of Hanover, Anne Arundel County 72 



VIII. Near view of layers of carbonate of iron nodules in the Arundel 

 clays, Reynolds Iron Mine, 1 mile south of Hanover, Anne 



Arundel County 80 



IX. Fig. 1. — View showing Patapsco sands overlying Arundel clays, 



Cedar Hill Mine, Timberneck, 1 mile southwest of Hanover. ... 84 

 Fig. 2. — View showing ledges of indurated sand in the Patapsco 

 formation which is overlain by greensands of the Aquia Eocene 



in cut of R. F. & P. R. R. near Aquia Creek, Virginia 84 



X. Fig. 1. — View showing massive variegated clay of the Patapsco 



formation, near Hawkins Point, Anne Arundel County 88 



Fig. 2. — ^View showing Patapsco sands and clays overlain by Pleis- 

 tocene sands, B. & 0. R. R. cut, Rosedale Hill, Baltimore County 88 



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