100 Hayes and Campbell—Appalachian Geomorphology. 
region. The second cycle was much shorter, but the time was 
sufficient for the warping of the Cretaceous peneplain and the 
reduction of considerable portions of its surface to a second 
baselevel. The region has barely entered upon its third cycle, 
which has thus far been a period of elevation and active erosion, 
and a peneplain is again in process of formation. 
CONDITIONS PRECEDING CYCLE 1. 
Present knowledée of the physiography of the Appalachian 
province prior to the beginning of this cycle is extremely vague ; 
but the conditions which then prevailed are so intimately con- 
nected with the subsequent drainage, having determined the 
location of the ancestors of the present streams, that they should 
briefly be considered. As far back as the history of the proy- 
ince can be traced, from near the beginning of Paleozoic time, a 
continental land area existed to the eastward of the present 
Appalachian valley. How far this land extended eastward is 
not known with any certainty, but it probably reached some- 
what beyond the present Atlantic coast line. The process is 
not well understood by which the land included in the present 
Appalachian valley was added to this old continent. It has 
been generally supposed that the folding of the region and its 
elevation above sealevel occurred wholly in post-Carboniferous 
time. Recent investigations, however, afford ground for the 
theory that folding occurred at various epochs in the Paleozoic, 
and that during many of these periods of folding the land area 
was materially increased and the coast line of the interior sea 
was pushed further and further westward. 
Streams flowing westward from the portion of the continent 
now included in the southern Appalachian province bore down 
the materials eroded from the land and spread them out over 
the bottom of the Paleozoic sea. These rivers were certainly 
the early representatives of the present streams and a few may 
have persisted in their original courses to the present. The 
effect upon these streams of the additions to the land area was 
probably less marked in the northern than in the southern por- 
tion of the province. Thus in northern Virginia the drainage 
was westward, though by what stream or streams is not known, 
from the time of the first emergence of Paleozoic sediments until 
the entire province was raised above sealevel; in central Vir- 
ginia the New-Kanawha occupied much the same position as at 
