352 The American Geologist. December. 1896 
it and the crystalline schists of tlie older complex. North of 
Mill creek the series widens to about three miles and contains 
many bodies of greenish and reddish jasper. AtC'anon Diablo 
it narrows again, being folded in between ridges of the older 
rocks. On the mountain slope between the two forks of the 
canon the southernmost exposures of the basal conglomerate 
were observed. North of the canon the series widens to more 
than half a mile. The conglomerate rises along the slope of 
the mountains to an elevation of fully 1,500 feet two miles 
south of Slate's Springs. From that point it gradually sinks 
and disappears three miles north of the springs. Silicified 
sandstones and jasper appear along the trail north from 
Canon Diable leading to Dolan's. On the coast near Dolan's 
there is exhibited the most intense silicitication and shearing 
of the sandstones and shales observed at any point along the 
coast. From this point to Slate's Springs, a distance of two 
miles, the series gradually narrows and exhibits less silicitica- 
tion and shearing. About three fourths of a mile south of 
the springs the strike of the strata carries the jasper beds 
beneath the sea. A little north of this spot the underlying 
strata consist of alternations of thin bedded sandstone and 
slate, with dip either approximately vertical or to the north- 
east, in the latter case indicating an overthrow. In the slate 
probably not more than 300 feet below the jasper beds were 
found specimens of Inoceramus similar to those below the 
springs. This fossil seems to be the most abundant, aside 
from the plant remains, being found in the slates as far as 
they were traced, a distance of about four miles. Some spec- 
imens of this genus reach a diameter of nearly a foot. Such 
has been the shearing and compression to which the strata 
have been subjected that the larger fossils have been gener- 
ally flattened out, although the smaller ones are occasionally 
fairly well preserved. The main body of slate with layers of 
thin bedded sandstone has a thickness of about 50 feet, 
through the greater portion of which the fossils are scattered. 
The slates were traced to a distance of about three miles north 
of the springs and were found to contain fossil remains at 
nearly all points where they could be examined. A stratum 
of very hard coarse sandstone furnished a number of ver}^ 
])oorly preserved molluscan remains. Nearly a dozen species 
