Geological Notes on the Sierra Nevada. — Turner. '1\\ 
excepting leaves in coal mine No. 3, the writer has thus far round noth- 
ing: These leaves were nut well preserved. The mos1 numerous were 
those of a coniferous tree, probably belonging to the cypress family, 
possibly Sequoia. 
The division of the [one formation into three portions, which i h<- 
writer found to be good everywhere in Amador and Calaveras counties, 
does not appear to obtain in Butte county, where the deposits underly- 
ing Oroville table mountain are composed largely of fine white shales 
and clay, the overlying sandstone anil peculiar clay rock not being rep- 
resented. 
Nkocknk Auriferous River Gravels.* 
Under this term arc included on the maps of the Gold 
Belt, tlie river gravels which occur chiefly on the ridge tops 
where they were deposited in what were then valleys before 
the present deep canyons in the range were ciit. These grav- 
els arc of different ii»'cs, hut may be divided into two main 
groups: 1st, Tin- older gravels, composed chiefly of white 
quartz pebbles, and frequently capped by rhyolitic flows. 
These may he characterized, in a broad way, as the gravels 
formed before the volcanic period. 2d, A later series, contain- 
ing volcanic pebbles chiefly of andesite, and later in age than 
the rhyolitic Hows. These maybe called the gravels of the 
volcanic period. Such gravels are often capped by andesite- 
tuir. 
At a large number of localities fossil leaves have been found 
in fine layers in the gravel, and silicified wood of both decid- 
uous and coniferous trees, as well as of palms. The leaves 
indicate that the older gravels are of Miocene age-. The later 
gravels belong to the Pliocene period. 
Pliocene Shore Gravels. 
Overlying the lone formation and forming level tops to the 
ridges in the foothills of Amador and Calaveras counties are 
conglomerate and gravel beds, best seen to the west and south- 
west of Valley Springs. The pebbles in this material are 
from a variety of rocks, quartzite, uiica-schist, quartz-porphy- 
rite, granitoid rocks, andesite, and rhyolite being represented. 
Hhyolite pebbles are in places so abundant as to be character- 
istic of the material. 
The Pliocene shore gravels are id' the same age as the la- 
ter auriferous river gravels. They .appeal-, however, to have 
•Neocene includes the Miocene and the Pliocene. 
