88 CALIFORNIA ACADEMY OF SCIEMCES. [Proc. 3D Ser. 



small depth. In the deeper parts the bottom is dark green 

 mud. At the mouth of the valley the 120-fathom curve 

 stretches two or three miles into the Santa Barbara Channel. 



This valley, with the two off Point Mugu, within seven 

 miles to the eastward, is at the mouth of the Santa Clara 

 Valley. 



The 25-fathom plateau is very broad, stretching 7^ miles 

 broad off San Buenaventura. 



The geographical position of the head of the valley is: 



Latitude, 34° oof north; longitude, 119° 13' west. 



10. The Santa Barbara Channel. 



This channel is one of the principal features of the coast 

 of both Lower and Upper California and is not duplicated 

 on the Pacific Coast. It is formed by the islands stretch- 

 ing westward on the prolongation of the Santa Monica 

 Mountains on the south, and the mountain barrier of the 

 Santa Ynez Mountains, whose base forms the north shore. 

 The islands lie nearly parallel with the main land for sixty 

 miles, at an average distance of a little more than twenty 

 miles. The Santa Ynez Mountains reach 3,960 feet eleva- 

 tion five miles behind the town of Santa Barbara, and east 

 of the Rincon they are 2,000 feet high within a mile of the 

 shore. The islands are mountainous and reach 980 feet 

 elevation on Anacapa, 2,400 feet on Santa Cruz, 1,586 feet 

 on Santa Rosa, and 861 feet on San Miguel. 



The bottom of the channel reaches a depth of 341 fathoms 

 and exhibits no abrupt contours. The western entrance 

 shows 230 fathoms in mid-channel. Under the northern 

 shore the bottom is soft green mud to the depths; under the 

 island shore the mud is mixed with sand and broken shells 

 to about 40 fathoms. 



Off the northwest part of San Miguel Island the surface 

 of the water inside 25 fathoms shows the existence of a sub- 

 marine oil well. 



