184 THE COASTAL PLAIN EOKMATIONS OF CECIL COUNTY 



of Pond Creek. Several stumps of cypress are there exposed on the 

 beach at about the level of high tide. They are in place, and are 

 surrounded and imbedded in a peat deposit about six feet in thick- 

 ness. . This peat bed is overlain by five feet of sand and gravel 

 which grade up into nine feet of loam. These two sections are most 

 suggestive, but in order to bring out their full significance it would be 

 necessary to describe a number of similar deposits which occur in the 

 various localities within the State of Maryland. 



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

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

 developed 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 occasion- 

 ally 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 upwards into loam and at 

 its contact with the clay strongly suggests an unconformity. These 

 clay lenses are in some localities devoid of fossils but in others they 

 contain remains of marine and estuarine animals and land plants. 

 Many localities for these clays are already known and as exploration 

 advances new ones are frequently discovered. 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 ex- 

 posed 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 incrusted with crystals of pyrite. Sands and gravels of the 

 Talbot formation unconformably overlie the clays and constitute the 

 upper portion of the cliff. Half a mile further south the cliff still 

 maintains its former height, but the section has . changed. Some 

 ancient stream must have established its valley on the Baritan sand, 

 for here the surface of that formation, like a great concave depres- 

 sion, passes gradually beneath the beach to appear again in the cliff 

 a hundred and fifty yards to the south. In this hollow, lying uncon- 

 formably on the Baritan formation, is a bed of dark-colored clay 



