Metamorphic Rocks.—Fkuairbanks. 161 
/ 
about twenty miles. Capel creek cuts through the southern end 
of this ridge, and though in place the metamorphism is not great, 
yet the distinction from the Cretaceous is easily discernible. 
Cretaceous shales carrying Aucella outcrop on the west, but are 
separated by a dike of serpentine. On the east the shales rest 
directly against a body of dioritic rock, similar in appearance to 
numerous dikes with which the metamorphic ridge is filled. 
On James creek, north of the Hitna mines an exceedingly in- 
teresting section is exposed. For two miles the creek has cut 
through slates, mica and hornblende schists, and ancient intru- 
sive rocks. At the mouth of the canon the hornblende schists 
are followed by a dike of serpentine three hundred feet wide. 
From this there is an abrupt change to the unaltered but upturned 
and broken shales of the Knoxville beds. In these shales a mile 
eastward on Pope creek Aucella is found. 
About three miles east of Lower lake near the Knoxville road, 
massive sandstones considerably altered outcrop on the western 
bank of a little creek. The eastern bank about twelve feet away 
is formed of Aucella bearing shales and calcareous strata entirely 
unmetamorphosed and dipping eastward about thirty degrees. 
Unfortunately the actual contact is hidden by a slide of boulders 
from above. 
These examples are sufficient to show that there exists in the 
Coast Ranges of California a series of rocks for the most part 
greatly metamorphosed and separated from the lowest Cretaceous 
not only lithologically but also by a great non-conformity. 
No regional metamorphism is anywhere apparent in the Cre- 
taceous rocks; whatever the nature of the disturbance to which 
they have been subjected, it was not of a metamorphosing char- 
acter. In several instances, as at Sulphur creek and Knoxville, 
an alteration has taken place, but solely through thermal action. 
In places the older rocks are so little altered as to be easily 
confounded with the Cretaceous, and close examination and fa- 
miliarity with the regional characteristics are necessary to dis- 
tinguish them. The Aucella is a widely distributed fossil through 
the Lower Cretaceous, and is it not likely that it would have been 
found in some portion of the slightly altered metamorphics if 
they really belong to the Cretaceous? 
The exact age of the metamorphic rocks as yet remains un- 
ce 
known, They are probably not older than the Carboniferous, and 
