74 THE PLIOCENE AND PLEISTOCENE DEPOSITS OF MAKTLAND 



Wicomico in that it finds its greatest development on the Eastern Shore, 

 although large areas are present along the western margin of Chesapeake 

 Bay from Elkton southward to Point Lookout and in the valleys of all the 

 estuaries. It has suffered less from erosion than any of the other terraces 

 and maintains everywhere its original surface almost unmodified by the 

 present drainage. The altitude of the Talbot terrace, where it abuts 

 against higher land lies very constantly at an elevation of about 40 or 45 

 feet, except in southern St. Mary's county where it gradually declines 

 southeastward to about 10 feet near Point Lookout. From its landward 

 margin the Talbot terrace slopes away toward the surrounding waters 

 where it either terminates in a wave-cut cliff (Plate XIV, and Plate XIX, 

 Pig. 1) or else passes down to tide level and merges with the modern 

 beach (Plate XV, Pig. 1). 



The Eecent Terrace. — Below the Talbot terrace is situated the 

 Eecent terrace. This is principally confined to the submarine division of 

 the Coastal Plain and is co-extensive with it. It everywhere wraps 

 around the subaerial division as a border and also extends up the river 

 valleys as a terrace formed by recent streams. Within the Bay and its 

 estuaries it is identical with the wave-cut and wave-built terrace, while 

 along the Atlantic shore it forms the modern beach and extends out under 

 the ocean as the surface of the continental shelf. Thus it appears that 

 the Eecent terrace is principally submarine. What is known regarding 

 the contour of its surface has been determined by soundings. In this 

 way it has been shown that the surface of this terrace is a plain, sloping 

 gently from tide to a depth of 600 feet at a distance of about 100 miles 

 off shore. The Eecent terrace is usually separated from the Talbot 

 terrace by a well-defined scarp, although at times the surfaces blend 

 without any marked interruption. (Plate XIX, Fig. 2, and Plate XXII, 

 Fig. 1). 



Up tn this point in the discussion the various terraces have been 

 described as wrapping around each other in concentric borders. This 

 arrangement, although the typical one, is not always present, for fre- 

 quently one or more terraces may be wanting in places where they would 

 normally be expected to be present. At such times the descent from the 



