Santa Barbara Channel^ etc. — Yates. 51 
volcanic breccia, composed of porphyritic and trappean rocks, 
having a distinct stratification with a dip of 30° southeast. 
Several spars extend out some distance from the shore line 
and others have been worn away by the surf until they form 
small rocky islets, while the porphyritic rocks, which have 
weathered out of the breccia, lie as smooth bowlders at the 
base of the cliffs. 
From this point the hills rise sharply to a hight of from 250 
to 300 feet, and run southeasterly to the main backbone of the 
island which lies on the line of its longest axis. 
The highest points on this range were visited, and the alti- 
tude was found to approximate 1,400 feet. 
Several high peaks are grouped together about five miles 
south from the wharf, being on the northern side of the line 
of the long axis of the island. 
Three of these high peaks lying within a mile circuit were 
measured, the first, Black mountain, indicated a hight of 1,325 
feet ; crossing from this peak over a depression of 350 feet be- 
low the first summit we find rhyolite and white bituminous 
shale. The next peak south, (Saddle mountain) is about 100 
feet higher than Black mountain. 
Between this point and the hills on the southeastern side of 
the Canada de la Cruz (Caiion of the Cross), we found lime- 
stone in the bed of the creek, together with fossil oysters (Os- 
trea titans) and other Miocene fossils. Southeasterly from 
Saddle mountain, and lying between Canada de la Cruz and 
the ocean there is an intrusion of syenite, the extent of which 
has not been ascertained, nor did I discover the line of junc- 
tion between the Miocene and Pliocene. 
On the north side of the island, about ten miles from the 
wharf, near the mouth of Saledad Caiion, we found an excel- 
lent exposure of strata, consisting of about 90 feet of Post 
Pliocene deposit, containing fossil bones of vertebrates, and at 
one place, fossil Physas, (P. d'orbignianaj, at a depth of some 
75 feet below the surface. 
This deposit is horizontal and overlies strata of older rocks, 
probably Pliocene, which dip 13° N. E. and contain Pecten, 
Turbinella ctcstrum, and Hinnites gigeantea in abundance, 
and ir an excellent state of preservation. 
From this point to the southwestern extremity and around 
the west end of the island to the pointwhere the main range of 
