Klamath Mountains, California. — Hershey. 235 
but also by evidence recently communicated to me by ^Ir. Dil- 
ler and in tbat region may be found the source of the Paleo- 
zoic chert in the Bragdon conglomerates. The explanation 
seems to be that the eastern shore-line of the Bragdon body 
of water was just a little eastward from the site of the present 
Sacramento river, while northeastward from it erosion was 
effective on a land whose surface formations were largely the 
slates, limestones and cherts of the Paleozoic series. 
The absence of marine fossils and the presence of some 
plant remains in the Bragdon formation may indicate that it 
was not laid down in the open sea, but in an inland bodi* of 
water, perhaps brackish in character. 
The fact which I have endeavored to bring out by this brief 
resume of a portion of the geologic history of the southern por- 
tion of the Klamath region is that at the close of the Bragdon 
epoch of deposition and just preceding the brogenic activity 
whose products I am about to describe, the territory was under- 
laid by four practically continuous sheets of rock, a foundation 
of schists, a thick layer of Paleozoic rocks, a thin layer of vol- 
canic materials and a thicker " layer of Mesozoic sediments. 
It is by following the contacts between these four layers that 
the structure of the region may be truly and readily deter- 
mined. 
Considered first as to its broader features only, the south- 
ern portion of the Klamath region may be described as consist- 
ing of a central ridge of schists, bordered on the west by a 
great, unsymmetrical geosyncline, and on the east by the west- 
ern limb of another great geosyncline. The first geosyncline is 
limited on the v/est by another belt of schist, chiefly the 
Abrams mica schist, which forms the South Fork mountain 
and is prolonged northwestward to and probably across the 
Klamath river near Wichiper. The sandstones of the Coast 
Range region adjoin this schist belt on the west. ]\Ir. Diller 
has informed me that toward the north, approaching the Klam- 
ath river, long, narrow belts of schist alternate with narrow 
belts of sandstone, the latter dipping eastward as though going 
under* the schists. This apparent anomaly is <^vidently due to 
a series of faults. It is further evident that the Coast Range 
formations have buried the western portion of the schist belt 
which latter may extend, immediately under the sandstone, 
far toward the coast. 
