Geology of California. — Turner. 309 
it seems to me that the evidence is not yet sufficient to classify the 
limestones of the middle Sierras as Carboniferous." In this connec- 
tion it might be well to state that the United States Geological Survey 
has obtained specimens ofFusilina ci/Undrica, Zaphrentis,a,nd abun- 
dant rounded crinoid stems in limestone in the older rocks of the 
Bear mountains and their continuation northward. According to Mr. 
C. D. Walcott, who is regarded as authority both here and in 
Europe, Fusilina is not known to occur below the Carboniferous 
or higher than the group usually called Pei-mian, which is so 
closely related to the Carboniferous that it has been relegated to 
that period by the United States Geological Survey. 
The above belt of Carboniferous rocks of the Bear mountains 
lies just west of the great diabase mass that forms the high ridge 
of which Bear mountain and mount Joaquin are culminating 
points. The rocks of it are not in general greatl}^ altered, and 
consist of fine-grained siliceous rocks (phthanites),* quartzite and 
limestone, with a good deal of black argillaceous schist. 
The broad belt of older rocks lying to the east of the Mother 
lode is much more altered than this belt of the Bear mountains. 
Nevertheless, the fossils found in the limestones of this eastern 
belt are the same. Fusilina cylindrica and rounded crinoid 
stems were found by the writer in the limestone at Hite's Cove in 
Mariposa countv, and rounded crinoid stems occur in the lime- 
stone at Cave Cit}- and other points along the great belt of lime- 
stone. 
The prevalent rocks of this eastern belt of older rocks are argil- 
laceous and mica schists, quartzite, and limestone, which is us- 
ually crystalline. 
The term "Calaveras formation," as used by the United States 
Geological Survey on the geological maps of the Gold Belt, includes 
all of the Paleozoic sedimentary^ rocks of the Sierra Nevada. The 
two belts of rock just described thus belong to the "Calaveras 
formation." 
Mr. Fairbanks considers the serpentine of the Sierra Nevada as 
*The term phthanite is used by the writer to include all the very fine- 
grained siliceous rocks which have not been subjected to sufficient pres- 
sure to be rendered schistose, and in which the silica is largely second- 
ary. These rocks are presumed to have been originally shales and lime- 
stones. The silicified shales or jaspery rocks of the Coast ranges and 
Lydian-stone or Idesel-schiefer as defined by Geikie in his Manual of 
Geology, 1885, p. 123, are included in this term. The term kiescl-schle- 
fer, or siliceous schist, is evidently misleading, since the rocks so-called 
are not schistose. 
