26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 149 



The Okefenokee shore is very conspicuous on the map of the 

 Collins, Ark., 7^2 -minute quadrangle, where it is separated from the 

 adjoining Sunderland or Coharie terraces by a 30-foot scarp. It 

 nearly coincides in location with the Sunderland beach, which seems 

 to have been cut away locally by stream erosion. 



The contact with the Sunderland terrace, here very narrow, is 

 shown on the Philipp, Miss., quadrangle along the foot of the bluff 

 between Paynes, Tallahatta County, and Oxberry, Grenada County, 

 where it is marked by the 145-foot contour line. 



The Okefenokee terrace takes its name from the Okefenokee 

 Swamp in southeastern Georgia and adjoining Florida, which is its 

 most distinctive feature. Otto Veatch (Veatch and Stephenson, 1911, 

 pp. 35, 36) described the "Okefenokee plain" as "a wave-built, 

 marine terrace, recently raised above sea level." "Perhaps 125 feet" 

 is the highest altitude assigned to it by Veatch. MacNeil (1950, 

 pp. 99, 102) referred the terrace to a shore line near 150 feet. A 

 closer approximation is 145 feet. 



Wicomico terrace (shore line 100 feet). — The shape of the Wicom- 

 ico bay is shown in figure 15. At the beginning of the 100-foot stage 

 the Mississippi Valley was flooded for several miles above the Louisi- 

 ana line into Arkansas. The shallow head of the bay became silted 

 up by the muddy river, and distributaries of a delta pushed southward 

 nearly 30 miles into Louisiana. The delta ended near Epps in Carroll 

 Parish (Mitchiner quadrangle) in water about 20 feet deep. 



Along the Ouachita Valley tidewater extended 50 miles beyond the 

 state boundary as far as Camden, Ark., where the present floodplain 

 covers the Wicomico terrace. On the Moro Bay quadrangle a low 

 scarp passing Ebenezer School separates the Wicomico terrace from 

 a low part of the Okefenokee terrace. A much higher scarp adjoins 

 the Wicomico south of the river. 



The 100- foot contour line lies near the bottom of a high bluff from 

 Twin Oaks on the Bastrop quadrangle to Collinston on the Collinston 

 quadrangle. The Wicomico terrace extends from this line eastward 

 beyond the limits of the quadrangles (fig. 13). It slopes very gently 

 southward and merges into the Penholoway terrace near Collinston. 



In Union Parish, La., patches of Wicomico terrace border the 

 uplands west of the Ouachita, notably at Litroe and Gravel (Haile 

 quadrangle). Farther south, in Ouachita Parish, there are areas west 

 and south of Monroe. Beyond these the Wicomico shore lay close 

 to the Ouachita River to Harrisonburg, where it turned southwestward 

 to the mouth of the Red River estuary below Alexandria. 



