112 ASPHALTUM OF LOS ANGELES VALLEY. 



point is limited, appearing to be the commencement of a series of outflows which are found 

 occurring at intervals eastward beyond the Los Angeles river ; with this deposit may be 

 classed — 



8 and 9. The deposits on the Santa Clara river tributaries and among the Susanna hills. — These 

 are but the eastward continuation of the foregoing outflow. If a line be drawn from the deposit 

 upon the banks of the Buenaventura river in a southeast direction it will touch in its course 

 several disturbed districts containing deposits of bitumen, until it reaches the low hills north of 

 the Pueblo Los Angeles, where the largest overflow has occurred. The small stream which 

 rises in the low ranges between the Buenaventura and Santa Clara rivers, and finds its way 

 down to the latter stream, about 12 miles up its valley, received the provisional name of Tar 

 creek, from its passing through a small valley in which several very extensive outpourings of 

 the bitumen were observed. Several small wells or springs were found here delivering small 

 quantities which had consolidated further down on the slope. The bitumen occasionally pours 

 into the creek, and is washed down into the Santa Clara river. It was detected here at the 

 point of debouche by the main party travelling up the Santa Clara, and observed by Mr. Camp- 

 bell along the line of the creek in a cross trail made by him from Matilihah to the Santa Clara 

 river. From these deposits occurring in a rocky district troublesome to reach they are not 

 available sources of bitumen. They occur in the brown sandstones last described. Deposit No. 

 8 has already been alluded to as most distant from the shore. 



A deposit occurs on the Santa Clara river, about 8 miles up the valley ; it occurs in one of 

 the ranges of the Sierra Susanna, is in close proximity to whitish amygdaloid trachyte, met 

 with in brown sandstones accompanied by a sulphur spring, and is on the right bank of the 

 river. Report speaks of other deposits occurring more easterly along the chain of hills which 

 run toward the Cordilleras. 



10. Deposit of Los Angeles valley. — This occurs between one and two miles north of the 

 pueblo in an air-line, but as the low range of the Sierra Monica, in which it is found, runs east 

 and west, the road winds round northwards to reach it. These hills are a brownish yellow 

 sandstone, 120 feet thick, passing into a hard shale lower down, which is covered up by a bed 

 of soft white argillite, 20 feet thick, in turn covered up by a thin brownish fissile slate, 30 feet 

 thick; above all is a capping of porphyry and granitoid drift gravel. The strata are tilted at 

 a high angle dipping northwest from 40° to 75° ; upon their upturned edges the drift rests. 

 Whitish trachyte and greenstone are the upheaving rocks which run north 60° west, and alter 

 the sandstones in contact, rendering them hard^ sonorous, and giving them a line of cleavage 

 nearly vertical to the plane of deposition. The asphalt is protruded through these strata near 

 its contact with the argillite, forming distinct wells or springs, which overflow. The land 

 where they lie is owned by Captain Dryden, who, at the time of visit, was sinking a pumping 

 apparatus for hoisting up the bitumen, which is very liquid at this locality, where it forms a 

 small pond a fourth of a mile in circumference, thinner in the centre than at the edges. Like 

 the other varieties, it readily dries, and forms a solid pavement some yards around the edge of 

 the wells. A large quantity is occasionally raised and sold at the rate of 40 gallons for §5 = 

 $1 for 8 gallons. It is in some demand for flooring and roofing. The quantity drawn at 

 present seems to have no effect in diminishing the supply ; but as intervals of rest occur, owing 

 to the limited demand, it is difficult to say what continuous supply could be derived from this 

 source. Mr. Trask, in his report, (Doc. No. 14, Calif., session 1855,) calculates the amount 

 of asphaltum in the counties Santa Barbara and Los Angeles as not less than 4,000 tons. As 



