NOVEMBEB 8, 1907] 



SCIENCE 



641 



fringing the shore and the larger rivers. Re- 

 entrants of this terrace penetrate the next 

 higher terrace along the Chowan, Roanoke, 

 Pamlico and Neuse rivers. The elevation of 

 the surface of the terrace varies from sea 

 level to from 20 to 25 feet at the foot of the 

 scarp separating it from the next higher ter- 

 race. The uplift vphich formed this lovpest 

 terrace was so recent that the terrace is but 

 poorly drained. Its surface is very level, and 

 much of it is swampy. Within the area 

 where this terrace attains its maximum de- 

 velopment are the Hyde County and Great 

 Dismal Swamps and Albemarle and Pamlico 

 sounds. Both of the swamps include large 

 lakes, resting in slight depressions in the ter- 

 race surface. Fossils have been found in the 

 materials composing this terrace at several 

 places. 



Beginning at the Virginia line in Gates 

 County, and extending southward to the coast 

 in western Carteret County, then swerving 

 southwest along the coast to the South Caro- 

 lina line is a sandy ridge separating the two 

 lower terraces. This ridge is well shown on 

 the topographic maps of the Beckford and 

 Edenton quadrangles of the United States 

 Geological Survey. It is also well developed 

 in western Pamlico and eastern Pender coun- 

 ties. The eastern side of this ridge is a well- 

 defined scarp. The summit is sandy, with 

 long, low, rolling sand hills extending north 

 and south, their major axis parallel to the edge 

 of the scarp. The elevations along this ridge 

 vary from 40 to 60 feet. The land slopes 

 ofi gradually on the western side of the ridge 

 to a broad level plain, at an elevation of from 

 30 to 50 feet above sea level, the second ter- 

 race. This terrace extends as a narrow 

 band across the coastal plain. About 10 miles 

 in width near the Virginia line it gradually 

 widens to the southward and in Pender 

 County has a width of from 25 to 30 

 miles. The surface of this terrace while 

 better drained than the lowest lying terrace 

 still contains many large swamps, such as 

 Angola Bay. Fossiliferous beds occur within 

 the materials composing this terrace. 



The next higher terrace lies at an elevation 



of 60 to 80 feet, with a width of from 20 to 

 25 miles. It is well developed in the vicinity 

 of Williamston and Greenville and covers 

 most of the Parmele and Falkland quad- 

 rangles. The scarp separating it from the 30- 

 to 50-foot terrace is low and at many places 

 the two terraces grade into each other in a 

 manner similar to that in which the lowest 

 lying terrace in some places passes gradually 

 into the terrace at present being formed be- 

 neath the sounds. The eastern edge of this 

 terrace is very irregular, although having an 

 approximately north-south trend. Broad re- 

 entrants of the next lower-lying terrace ex- 

 tend far within its borders along the large 

 rivers. 



The fourth terrace has an elevation of 110 

 to 140 feet and is best developed in the Wil- 

 son, Tarboro and Rocky Mount quadrangles. 

 It has a width of approximately 25 miles. 

 The scarp separating this terrace from the 

 60- to 80-foot terrace extends approximately 

 north and south and is steep and well defined. 

 In the central and northern parts of the 

 coastal plain the materials forming this ter- 

 race rest in many places directly upon the un- 

 even surface of the rocks of the Piedmont 

 Plateau. In this region, therefore, the higher 

 terraces are but poorly preserved. The west- 

 ward extension of the 110- to 140-foot terrace 

 is limited by a long narrow ridge extending in 

 a north-south direction through Nash, Wilson 

 and Johnston counties. The elevation of the 

 surface of this ridge varies from 220 to 260 

 feet. In appearance the ridge resembles that 

 described as separating the two lower ter- 

 races. 



On the western side of this ridge the land 

 slopes gradually to the next higher terrace at 

 an elevation of 180 to 200 feet. Because of 

 the uneven surface of the Piedmont rocks thi^ 

 terrace is but poorly preserved north of 

 Johnston County. Broad level stretches oc- 

 cur, however, in northern Sampson and east- 

 ern Cumberland counties. 



Remnants of terraces at 220 to 260 feet and 

 at 280 to 320 feet can be seen on the topo- 

 graphic maps of the Springhope and Kenly 

 quadrangles. It seems probable, however, that 

 accurate topographic mapping of the south- 



