VARIOUS LOCALITIES OF THE ASPHALTE GROUP. 63 



I am inclined to look upon this series as the most recently elevated strata in California ; the 

 upper soft rock, which is the most persistent and easiest recognized, heing the distinguishing 

 stratum. I have not observed them north of San Luis bay, not having reached the coast north 

 of that point. It is likely they extend along shore to Punto Gordo ; the deeply excavated 

 beach would imply some such soft rocks at the base of the Santa Lucia range. From San 

 Luis, south, they may be traced, by Napoma, along shore, and occupying the low hills of the 

 Saint Inez range, at Point Concepcion ; thence under the terrace at Gaviote pass, and along 

 shore, close to Santa Barbara, where it rises up to ibrm a terrace cliff barrier 100 feet high. 



From Santa Barbara it may be traced, not far from the shore, to San Buenaventura ; and 

 east of the Santa Clara river it leaves the shore, running directly east, and forming the upper 

 beds of the low hills called the Sierra Monica, whence they may be found running out north of 

 the town of Los Angeles. 



In the Santa Margarita valley these strata were not observed occupying a prominent posi- 

 tion — i^erhaps the centre of the plain may be occupied by them — but they were found in the 

 northern end of the Santa Maria valley, where they form the latest beds of the San Jose moun- 

 tains on both slopes, and are found occupying a position superior to the ostrea and i)ecten 

 beds, corresponding to those described in the account of Santa Margarita valley. In the valley 

 of Santa Maria river they were found traversing the base of the hills about 150 to 300 feet 

 above the level of the valley ; upon these layers the lowest hill terrace of the valley was placed, 

 the strata extended twenty miles along the hills towards the head-waters of the river. This 

 is the furthest point inland at which they were observed, about sixty miles from the sea. In 

 their extended course (above 200 miles from north to south) they have a varied dip along the 

 San Jose range, whose axis is granite ; they are unaltered in character, and have an elevation 

 on the east side not more than 15°, while on the west it approaches 45°. 



In the valley of San Luis the dip is 20°, while along the coast at Gaviote pass it is 40° 

 Both in Santa Barbara and Los Angeles counties it varies from 8° to verticality, in jiroportion 

 to its proximity to the trappean and trachyte eruptions. In the eastern end of the Sierra 

 Monica, north of Los Angeles, the strata are almost vertical. 



Though not observed further north on this survey than Estero bay, there is no reason to 

 doubt of their occurrence in the valleys of the Coast Eange further inland. From Dr. Trask's 

 description, I am inclined to think that beds found by him nea^r the mouth of the Pajaro river, 

 and those observed by Mr. W. P. Blake, near the town of Monterey, are extensions of those to 

 the north. Dr. Trask notices that these beds, the two upjJer series of the group described 

 here, are never found at a lofty elevation — that they are not found above an altitude of 500 

 feet. This was also observed upon this survey, with one exception, the Santa Maria valley. 



Everywhere these beds have been observed, they seem to have suffered extensively by 

 denudation. In San Luis valley, towards the south, these strata merge into the San Lucia 

 range, and shut up the valley in that direction. Around the town of San Luis, and north to 

 the ocean, these soft strata have been removed, and have left only the harder conglomerate 

 standing here and there as landmarks to indicate the former position of the strata. 



The history of these beds would be incomplete if notice was not taken of their occurrence upon 

 the hills which form the divert between the valleys La Purissima and Santa Inez. In descend- 

 ing this hill slope on the southeastern side, or entering the Santa Inez valley, the upper yellow 

 slate was met, forming the sides of a caiion down which the wagon road led to the valley ; on 

 examining these shales, they were found to contain in places the impressions of numerous bodies 



