Geol.-Vol. I.] DAVIDSON— SUBMERGED VALLEYS. 87 



6^ miles from the rocky shore; runs parallel with the shore 

 for five miles to a depth of 390 fathoms; then nearly north 

 for four miles to 300 fathoms and curves to the NW. for three 

 miles to 25 fathoms within a third of a mile of the receding 

 beach. At the 275 fathom curve it gives off a branch towards 

 the west for three miles to the 200 fathom curve, and then 

 turns sharply to the north for three miles, ending with 25 

 fathoms about half a mile from the beach. 



The eastern head is double and the innermost head is 

 less than a third of a mile from the beach, and only i^ 

 miles from the head of the western branch. 



The fine gray sand is found out to 25 fathoms, and is 

 mixed with mud to 50 fathoms; then green mud to 500 

 fathoms, except in one or two cases, when green mud and 

 sand are given. 



The geographical position of the eastern head of this val- 

 ley is ; 



Latitude 35° 05^' N. ; longitude 119° 06' W. 



9. The Hueneme Submerged Valley. 



As already mentioned, this valley heads close to the low 

 shore of the broad Santa Clara Valley, eight miles west of 

 Point Mugu, and nine miles east of San Buenaventura. It 

 is therefore directly at the eastern entrance to the Santa 

 Barbara Channel. The 25-fathom curve reaches so nearly 

 to the beach that boats can land here when the surf alongr the 

 Other parts of the beach forbids an attempt at landing. The 

 axis of the valley is nearly north and south, and is seven 

 miles long to the 300 fathom curve. The valley is very nar- 

 row, averaging about a mile wide, and even the 25-fathom 

 plateau on either side is sharply defined. It opens on the 

 eastern prologation of the sharp ridge of Anacapa Island, 

 which island, with Santa Cruz, Santa Rosa, and San Miguel 

 is on the western prolongation of the well marked line of 

 the Santa Monica range. 



On both sides of the valley the bottom on the plateau at 

 15 fathoms is brown mud, a very unusual exhibition at that 



( 2 ) June 26, 1897. 



