Esmeralda County, Nevada.—Turner. 273 
SOME CRYSTALLINE ROCKS OF SOUTHERN 
CALIFORNIA. 
By Oscar H. Hersuey, Berkeley, California. 
INTRODUCTION. 
The olde: crystalline rocks of the state of California have 
not received the attention which they deserve. Through the 
nicchievous influence of early studies on metamorphism in 
the Coast Ranges, the idea has gone abroad that virtually all 
of the highly crystalline schists west of the summit of the 
Sierra Nevada range represent zones of contact metamor- 
phism in strata ranging in age from Devonian to early Cre- 
taceous. Walcott and Turner have demonstrated that in east- 
ern California, in Inyo county, there is a lower Cambrian ser- 
ies of quartzytes, limestones, slates and shales resting uncon- 
formally upon an old complex of gneiss, schist and granite; 
but the idea has not until quite recently been seriously enter- 
tained that the same pre-Cambrian series intruded by a Meso- 
zoic granite underlies and forms the foundation of much of 
the country west of a line drawn along the axis of the great 
valley of California and thence prolonged southeastward to the 
gulf of California. 
This subject of the older rocks is of special interest to the 
present writer. In the field of California it is in its infancy. 
Presently general interest in it will be aroused and an effort 
will be made to bring into some systematic arrangement thc 
fragments of knowledge of the supposed pre-Cambrian rocks 
which we now possess and which will be rapidly extended. 
Students will no longer assume that a given outcrop of schist 
represents strata no older than the Paleozoic, for no other 
reason than a conviction that metamorphism in California 
is no indicator of age. Doubtless in the early stages of this 
ingairy there will be many errors made and much confusion. 
The history of the investigation of the pre-Cambrian rocks 
of the Lake Superior region will be repeated with interesting 
variations. Not having as a basis, the precision of paleontol- 
ogical evidence, but being dependent entirely upon structure 
studies, it is probable that at times entire series will be reversed 
in chronological order. 
