54 CALIFOKNIA ACADEMY OF SCIENCES. 



Ventura is the great development and the high elevation above sea-level of the 

 Pleistocene de^iosits in that locality. The terrace on which the city is located and 

 the hills immediately back of the city are of Pleistocene origin. This is shown by 

 the marine fauna collected at different localities in the vicinity. 



The first locality visited was along the course of the old irrigating ditch, which 

 runs at an elevation of about ewo hundred and fifty feet above sea-level on the eastern 

 side of the valley west of Ventura. The hills along which this ditch runs rise to 

 over five hundred feet in height, and are composed of fine, soft, yellow sandstones 

 which dip south at an angle of 50 \ These sandstones were examined for about 

 one-half mile north of Ventura along the ditch. This exposure represents a thick- 

 ness of at least one thousand feet. Several of the strata were fossiliferous and 

 yielded a fauna similar to that of the Pleistocene of San Pedro. The upper beds, or 

 those nearest the ocean, contained a fauna similar to the upper San Pedro series, 

 while that of the beds further down in the series contained such species as are com- 

 monest in the lower San Pedro series. The lower beds were characterized by the great 

 abundance of Turritella coojjeri. An outcrop in a ravine near the new hospital on the 

 north side of Ventura contained a fauna similar to that of the upper beds along the ditch. 



There is an exposure of fossiliferous Pleistocene strata between Barlow's ranch 

 house, three miles east of Ventura, and a prominent point, called "The Peak," north 

 of the house. "The Peak" has an elevation of one thousand and seventy feet, ac- 

 cording to the United States Coast and Geodetic Survey. The highest point at which 

 fossils were obtained was about two hundred and fifty feet below the summit, but the 

 same formation extends to the top, and probably comprises all of the sediments form- 

 ing the elevated ridge which lies back of Ventura from the ocean, and extends 

 parallel with the coast for several miles east of Ventura. 



The fossiliferous strata exposed were about twenty-five feet thick, and con- 

 sisted of five or six layers of shells from three to nine inches in thickness, separated 

 by fine, soft, light yellow sand layers. The whole series was unconsolidated, except 

 for local hardenings in the shell layers, and was oxidized but little. The dip of the 

 strata was from 30" to 40 south, which corresponded nearly to the general slope 

 of the main ridge, whose axis was parallel with the coast, and of which "The 

 Peak " was the highest point. 



The fauna collected consisted of about fifty species, all of which are common 

 to the San Pedro series. The similarity between this fauna and that of the upper San 

 Pedro series, and the incoherency and lack of oxidation of the matrix, leave little 

 doubt as to the age of these beds. They are of Pleistocene origin, and, moreover, are 

 synchronous with the upper San Pedro series. Their elevation of about eight hun- 

 dred feet above the sea-level seems remarkable, but only confirms the theory of the 

 recent great elevation of the coast of California from San Francisco southward. 



