48 TOPOGKAPHIC DEVELOPMENT OF KLAMATH MOUNTAINS, [hull. 19(3. 
ments, there were no pronounced movements until near its close. 
The Klamath peneplain had attained its greatest development during 
the deposition of the Wymer beds, and the period of long- continued 
relative stability was changed to one of vigorous diastrophism, which 
resulted in compressing the narrow belt of Miocene sediments of the 
coast along faults in such way as to give them a general dip north- 
eastward. The dip of the strata is usually from 10° to 25°, but at 
Rio Dell a thick section of sandstones and shales dips 70°. These high 
dips are confined to a small portion of the southwestern border of the 
Eel River area, and the inclination is toward the northeast. The 
prevalence of northeasterly dips throughout the Mad River area, as 
well as throughout the greater part, if not the whole, of the Eel River 
mass, including that of the South Fork and the vicinity of Round 
Valley, suggests faulting. In general, the amount of disturbance in 
each area decreases northeastward, so that the greatest displacement, 
appears to be limited to a comparatively narrow belt near the coast. 
Along the eastern border of the Miocene area the strata were in most 
places but little disturbed. 
The dislocation of the Miocene sediments brought them up to the 
sea level, but does not appear to have raised to any considerable 
extent the Klamath Mountain region, for the plain cut upon the soft, 
tilted, Miocene beds during a relatively quiet epoch immediately suc- 
ceeding the tilting accords approximately with the Klamath pene- 
plain. The Miocene dislocation must have been accompanied to a 
large extent by the dislocation of the underlying older rocks. Being 
near the seacoast, these irregularities were vigorously attacked and 
were reduced to gentler features showing well-defined marks of base- 
leveling, but the irregularities of the upland were not all removed 
before the Bellspring stage was brought to a close by an upheaval. 
OROOEOTC MOVEMENT INITIATING SHERWOOD STAGE. 
The uplift was differential. Near the coast there was but little 
uplifting; to the east it increased so that the crest of the range was 
raised nearly 2,000 feet, and the Klamath x^eneplain was warped and 
broken to a considerable extent, but not so much as to obscure the 
essential evenness of the peneplain. In like manner the Bellspring 
peneplain was somewhat affected. 
The uplift at the close of the Bellspring stage initiated that of th# 
Sherwood peneplain. The upturned beds of the Wildcat series were 
easily removed, exposing the older and harder rocks beneath. The 
plain extended inland in places under favorable circumstances for 
many miles. Near the coast, where carved upon the Wildcat series, j 
the plain has an altitude at present only a few hundred feet lower 
than the Klamath peneplain at the same place. Farther east the dif- 
ference in elevation between the Klamath and Sherwood peneplains 
increases, a feature which shows that the uplift closing the Klamath 
epoch was differential and greatest near the crest of the range. 
