Rocks of Southern California.—Hershey. 279 
to have better resisted the squeezing action. The appearance of 
the rock is that of a highly metamorphosed squeezed conglom- 
erate like those occuring in the Calaveras in the Sierra Nevada 
region, rather than as an altered, sheared, crushed and “rolled” 
coarsely porphyritic granite. 
The relation between the gneiss and Pelona schists could 
not be determined as the line of contact was everywhere ob- 
scured by intrusive granite or strips of Tertiary conglomerate 
and this remains one of the interesting problems of that re- 
gion. In Mint canyon, the first rock seen on the south of the 
Tertiary belt which lies along the schist and granite border is 
the conglomerate (?) gneiss which is the prevailing rock for 
over a mile. Indeed, except for large masses of intruded mus- 
covite granite, an east-west belt several miles wide seems to 
belong exclusively to this coarse pebbly gneiss. Its prevailing 
dip is southerly at a high angle. Narrower belts of the same 
type occur in the area of the finer gneisses. 
I am of the impression that the true succession is that the 
fine gneisses constitute the basal portion of the section and are 
the oldest rocks exposed in the state of California, probably 
corresponding to the Archean gneisses or ancient altered gran- 
ites of Nevada, Arizona and the Rocky Mountain region; the 
codrse, pebbly gneiss is next in age and represents a sort of 
basal conglomerate to the schist series, the “pebbles” probably 
having been derived through the erosion of the Archean gran- 
ites ; the yeliow mica schist is the third formation ; and the dark 
mica schists oi Pelona mountain the newest of this very 
ancient series. . The coarse gneiss and succeeding schists 
would thus bear to the Archean gneisses the same relation as 
exists between the Algonkian and Archean of the eastern states. 
‘The reader must not be led astray by the neatness of this 
classification as the above relation between the gneisses and 
schists is not proved, but merely suggested. 
THE ROCKS OF FRASER MOUNTAIN AND VICINITY. 
Gorman’s Station is in the extreme northwestern corner of 
Los Angeles county, just east of Fraser mountain. The nar- 
row northwest-southeast ridge (altitude about 6,000 feet) 
north of it, a member of the Tehachapai range and the actual 
divide at this point, is mainly an unsheared granite with flesh- 
