14 TOPOGRAPHIC DEVELOPMENT OE KLAMATH MOUNTAINS, [bull.196. 
single uplift, but by a number, separated by halts which were in some 
cases sufficiently long to allow the waves to develop prominent beaches, 
with sea cliffs and marine terraces, all of which are capped more or ] 
less completely by Pleistocene marine sediments. The first or oldest 
of this series of marine terraces must now be highest on the slope up 
from the sea, while the newer ones range successively downward to the 
present beach. The terraces are numerous and occur at many levels. 
The highest one yet found is 1,500 feet above sea level, and marks 
approximately the point at which subsidence changed to uplift. The 
two most prominent terraces are about 100 and 1,000 feet above sea 
level. 
While the waves were cutting terraces on the coast the rivers were 
cleaning out their filled valleys, or perhaps in some cases cutting new 
canyons around the filling. 
16. Coos Bay subsidence. — The latest movement on the coast of 
Oregon from Bandon northward has been one of slight subsidence, 
permitting the tide to run up the rivers many miles. 
The sequence of events may in a general way be illustrated by the 
diagram, fig. 1, in which the horizontal component represents time 
and the vertical component represents altitude of the land — the 
Klamath peneplain in particular — with reference to sea level. 
EOCENE MIOCENE PLIOCENE PLEISTOCENE 
- zsoo feet 
- 2OO0 » 
- /500 •• 
- IOOO - 
- SOO " 
Sea level —o — — 
Fig. 1.— Diagram illustrating the movements of the Klamath peneplain with reference to sea 
level. 
Notwithstanding the post-Klamath faulting (2) the land remained 
for a long time (1-3) at approximately the same level, allowing the 
development of the Klamath and Bellspring peneplains. The uplift 
(4), followed by a halt (5), resulted in the Sherwood peneplain. Another 
uplift (G) and halt (7) led to the features of the Garberville stage. 
The long upward movement (1-7) was followed by a slight recoil (8) 
and halt (9), filling the estuarine valleys, before the great uplift (10) 
which forced the sea back to the continental border. A time of high 
altitudes (11) ensued. The end of the swing was reached and subsi- 
dence (12) set in, halting (13) for a short interval before the greater 
downward movement (14) which depressed the Klamath peneplain to 
within about 500 feet of sea level. Elevation (15) began again; it 
was marked by many halts, when marine terraces were carved ; and 
finally there has been a local sag (16) along the northern coast of 
Oregon. 
Owing to the lack of characteristic fossils at important points the 
reference to the geological time scale in fig. 1 is not fully satisfactory. 
