NEOCENE STRATIGRAPHY. 323 



creamy, fine-grained shale to the hght or dark drab sandy 

 strata characteristic of the Merced, and which can be 

 traced to the fossiliferous beds of Soquel and Capitola. 

 (See plate xxiv.) 



At Point Montara the Merced lies upon the granite, 

 and at several places in the San Francisquito basin the 

 Merced series lies unconformably upon the Pescadero 

 series. There is thus some evidence of erosion or trans- 

 gression between the two periods. 



South of Half Moon Bay the same relation seems to 

 exist as at Santa Cruz, as indicated in certain well borings. 

 On Purissima and Tunitas creeks wells have been sunk 

 for oil to depths of from 600 to 800 feet. On Purissima 

 Creek, about a mile from the village of that name, a well 

 was sunk to a depth of 770 feet; oil was struck at 240 

 feet and from that depth downward. At that depth they 

 also struck " some fossil clam shells."* Calling to mind 

 the scarcity and character of the fossils of the white or 

 bituminous shale it seems probable that these clams be- 

 long to the horizon of the fossiliferous beds in the bluffs 

 on the coast. The suggestion is made that at that depth 

 is the top of the bituminous or white shale. In one of the 

 Tunitas Creek wells oil was reported at a depth of 350 

 feet. The well is 130 feet above sea-level and the dip of 

 the shaly strata southwest. The above facts would indi- 

 cate, if our interpretation is right, that the fossiliferous 

 beds at Purissima, etc., are quite near the bottom of the 

 series. 



Some of the early writers grouped the fossiliferous or 

 transition beds with the Monterey series, but it has seemed 

 best for the following reasons to group them with the 

 overlying Merced series : 



* Seventh Auu. Kep. of State Geologist for 1887, p. 101. 



