66 Hayes and Campbell—Appalachian Geomorphology. 
appearance of the first two papers above cited. He has carried 
his observations somewhat further toward the interior and de- 
scribes two well marked baselevel peneplains in eastern Penn- 
sylvania, New Jersey and portions of New England, the formation 
of which, he ascribes to long continued erosion in Cretaceous and 
Tertiary time. A general seaward tilting of the peneplain is 
described, but no attempt is made to locate the axes of their 
deformations. In 1890 Davis published a more comprehensive 
paper,} bringing in review all previous publications on the base- 
levels of the Atlantic slope and discussing the probable continua- 
tion of the peneplains, found in the northern portion southwest- 
ward over the whole of the Appalachian province. 
Thus the broad outlines and to some extent the details of post- 
Paleozoic history of the Atlantic slope and Mississippi embay- 
ment have been determined, but for most of the interior the 
details are still wanting. The present paper is an attempt to 
supply in some measure this deficiency. 
THE PROVINCE DEFINED. 
For present purposes the southern Appalachian province is 
regarded as embracing the region south of the Ohio and Potomac 
rivers and limited toward the east, south, and west by the Cre- 
taceous and the later formations of the coastal plain and Missis- 
sippi embayment. One or both of the present writers are per- 
sonally familiar with the greater part of this region, and many 
observations made in connection with the work of the Appa- 
lachian division of the United States Geological Survey are here 
for the first time brought together. The location of the region 
is exceptionally favorable for the study of its geomorphology. 
Surrounded on three sides by Mesozoic and later deposits, the 
relations of land and water which prevailed during post-Paleozoic 
time are fairly well determined. The character of the sediments 
serves to establish correlations between them and their corre- 
sponding erosion features. The intersection of erosion planes 
with deposits of known age serves to fix the date of each erosion 
period within narrow limits. Finally, the absence of glaciation 
and glacial deposits renders the interpretation of topographic 
forms and of drainage systems much easier than in regions 
+The geologic Dates of Origin of certain topographic Forms on the 
Atlantic Slope of the United States, by W. M. Davis: Bull. Geol. Soc. 
Am., vol. ii, 1890, pp. 545-581. 
