GEOLOGY OF THE SOUTHERN COAST RANGES 557 
the base of the beds. Near the road, two miles northeast of 
San Louis Obispo, the base of the Knoxville beds is exposed on 
a little hill. It consists of conglomerate, perhaps thirty feet 
thick, and dips easterly at a low angle. Exposed on either side 
of the hill and passing through under the conglomerate is one 
of the pre-Cretaceous basic intrusives similar to others near by 
in the Golden Gate series. This must have been the old sea 
bottom on which the conglomerate was deposited. In Reservoir 
Canyon, a little more than a mile southeast of this locality, is a 
hill about one-half mile in diameter formed of Knoxville shales 
and one thin layer of conglomerate. The shales are but httle 
inclined and are underlaid and surrounded on all sides by the 
upturned and nearly vertical sandstones and associated intru- 
sives of the Golden Gate series. Perfectly preserved specimens 
of Aucella were obtained from a concretionary nodule at the 
very base of the Knoxville on the south side of the hill. 
The second line of evidence, that of paleontology, leads to 
the conclusion that the series is not older than the Jurassic, the 
radiolaria as well-as the molluscan remains both agreeing upon 
this point. All the specimens of the latter so far obtained from 
the series are probably new species and appear to be indetermi- 
nate as far as the question of Jurassic or Cretaceous age is con- 
cerned. Only one locality of mulluscan fossils was discovered 
and that is located on the coast, six miles north of Port Harford. 
A small species of a pecten-like form occurs in great abundance 
here through a thickness of about eighty feet of black slate 
which stands vertical and is inclosed between dikes of diabase. 
The strata of the Golden Gate series consist of sandstone 
which forms fully four-fifths of the whole, numerous lenticular 
beds of radiolarian jasper, shale, and a little conglomerate. The 
whole has been upturned, folded, and faulted in a very complex 
manner and intruded at various periods by dikes of igneous 
rocks in great variety and abundance. The different members 
of this series have the same character as in other portions of the 
Coast Ranges where they have been described.’ 
™ Bull. Geol. Soc. of Am., Vol. VI, p. 82; U.S. Geol. Sur., XVth Annual Report, 
p- 415. 
