230 The American Geologist. April, 1901. 
grained compact quartzyte. In several places this shows shaly 
partings. Undoubtedly there is here evidence of the clastic 
character of the formation. 
In the Hay Fork section of Trinity county, the Salmon 
hornblende schist is well developed as a belt several miles in 
width lying between the mica schist on the east and the black- 
schistose slates of the Devono-Carboniferous on the west. In 
this area the schistosity is not so strongly developed and much 
of the formation is but little removed in alteration from a slate. 
In many places the bedding planes are distinct and indicate a 
formation originally not finely laminated nor yet very heavily 
bedded. 
Another area of this formation occurs on the east side of 
the great serpentine area of the Sierra Costa mountains, on 
Rush creek several miles north of Weaverville. 
We may now take a broader view of the schist series. The 
members are everywhere perfectly conformable to each other 
and evidently represent continuous sedimentation. At the base 
was an argillaceous sandstone with certain single heavy strata 
of nearly pure quartz sand. Following that was deposited a 
thin stratum of highly carbonaceous and siliceous shale. An- 
other change in conditions brought in a more argillaceous and 
calcareous sediment and then followed a long period of remark- 
ably uniform deposition of shale, sandy layers being few and 
fine in texture. All members of the series have been subjected 
to the same degree of metamorphism. Without shearing ex- 
cept locally, the first member was recrystallized into micaceous 
quartz schist, the second into graphite schist, the third into 
actinolite schist and the last seems to have passed through a 
slaty stage into hornblende schist. 
The discussion of the age of this Klamath schist series will 
be reserved for the close of. the paper. 
The Lozi'cr Slate series. — This is made up of a succession 
of black slates, quartzytes and limestone. The slates nearly al- 
ways have a schistose structiire due to shearing. The quartz- 
ytes make up a large part of the series and are fine-grained 
and often regularly and thinly bedded. The granular structure 
and detrital origin are quite apparent to the unaided eye. The 
beds of quartzyte alternate rapidly with the schistose slates. 
The limestones occur in long narrow dike-like masses which are 
