LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

SO LOWER CRETACEOUS DEPOSITS INT CALIFORNIA AND OREGON
fied in the deposits of the Yolla Bolly basin (Big Bar, Rattlesnake Creek,
and Redding Creek) in Trinity County. Most of these places were visited
by Diller (Diller, 1008, p. 379-384), whose accounts contain fossil determinations
by both Stanton and Knowlton, since both raolluscan fossils and
plant remains have been collected there. Concerning the rnolluscan fossils
from Big Bar, Stanton reached the conclusion tbat tbe horizon was within
the "upper Knoxville," which in this paper is that of the Paskenta group.
The deposits at Redding Creek were regarded by Stanton as being somewhat
higher, possibly within the lower Horsetown group. However, in
addition to the rnolluscan species mentioned by Diller, others have since
been obtained here by N. E. A. Hinds and by G. D. Hanna and the writer.
Without giving complete lists here, they include the following:
Pecitn calif amicus Gabb Phyllocc-rai trinitense nov.
Terebral*lCti californiea Stanton Haplocrioceras yollabollium nov.
The first two species of this list have been found at Stephenson's on the
Cold fork of Cottonwood Creek, in beds of Paskenta age, and the third
bas been found in similar beds at Riddle, Oregon. The bolotype of
Crioceras laivm Gabb probably came from this area, whence it had been
carried to its point of discovery on the Trinity River, Some of the species
found here have also been found at Locality 1065 (Calif. Acad. Sci.) on
Duncan Creek, in beds low in the Paskenta group.
From Rattlesnake Creek, Diller lists (1908, p. 382) only plants, although
he also mentions rnolluscan fossils. Tbe plants were regarded by Knowlton
as Jurassic. More recently, Parker D. Trask and the writer obtained
here various molhiscan fossils, including the following genera: Cyrena,
Corbvla, Astarfe, Goniomya, and Unio, all the species of which are new
and partly described here for the first time.
The locality at Big Bar on the Trinity River has yielded both plants
and Mollusea, all of which are listed by Diller (1908, p. 380-381). From
the twelve or more species of plants, Knowlton reached the conclusion
that the horizon was that of the "Jurassic of Oregon," which for the most
part is referable to the Paskenta group. The molluscsn forms obtained
here by Diller included Aucella craasicoUis Keyserling, Pecten, Mytilus,
Cyprina, and Unio, from which Stanton concluded (Diller 1908, p. 381)
that fcbey were "upper Knoxville," and, as already shown, this is correlative
with tbe Paskenta group, as are all the Cretaceous beds found in the
drainage of the Trinity Biver system.
Concerning the several residual deposits found in this basin Diller says
(1908, p. 402):
"The strata, containing tbe Jutaaaia flora of tbe Klamath Mountains are conspicuously
unconformable to the underlying Paleozoic rocks and contain not only &
marine, but ikJuo a fresh water fauna. They were deposited by the sea advancing
over the slopes of the subsiding Klamath Mountfuaa.