MARYLAND GEOLOGICAL SURVEY 97 



The following section may bo considered as typical for the Talbot 

 formation, although others occur which show a slightly different distribu- 

 tion of material as explained above. 



Section on West Side of Anacostia River South of Pennsylvania Avenue. 



Feet. Inches. 



Sandy loam, light yellow to brown in color 3 6 



Fine yellow sand with occasional solitary gravels or thin 

 lenses of gravel 4 to 6 inches thick; gravel up to 6 



inches in diameter 7 



Mass of gravels of all sizes unstratified, some several feet 

 in diameter, yellow sandy matrix, striae found on 

 gravels, materials generally fresh in appearance, a 

 few small lenses of yellow sand free from gravel pres- 

 ent. In places iron crusts have formed in the sand 

 and gravel, cementing them together (exposed) 11 



Total 21 6 



Along the shore of Chesapeake Bay and the lower courses of many of 

 its estuaries there occur at intervals deposits of greenish-blue clay devel- 

 oped as lenses in the body of the Talbot formation. Usually the base 

 of the clay is not visible, but its stratigraphic relations are such as to 

 leave no doubt that it, or a thin gravel bed on which it occasionally rests, 

 is unconformable on whatever lies beneath. The upper surface of these 

 clay lenses is everywhere abruptly terminated by a bed of coarse sand or 

 gravel which grades rrpwards into loam and at its contact with the clay 

 strongly suggests an unconformity. These clay lenses are in some locali- 

 ties devoid of fossils, but in others they contain remains of marine and 

 estuarine animals and land plants. Some of the more typical exposures 

 will now be described. 



Along the shore, about a mile below Bodkin Point, Anne Arundel 

 county, the variegated clays of the Baritan formation are finely exposed 

 in a cliff some thirty feet in height. These clays occupy the greater portion 

 of the section and carry an abundance of lignite more or less encrusted 

 with crystals of pyrite. Sand and gravels of the Talbot formation uneon- 

 formably overlie the clays and constitute the upper portion of the cliff. 

 Half a mile farther south the cliff still maintains its former height, but 

 7 



