Vol. IV] ANDERSON AND MARTIN— NEOCENE RECORD 31 



Quite similar beds of ash or tuff, though not so thick, occur 

 in the lower Miocene beds of Point Sal, as described by Dr. 

 Fairbanks/ It is quite likely that the ash beds at Point Sal 

 are a part of the same general outburst that spread the ash 

 and tuff over the San Luis quadrangle not far distant. There 

 are many geological facts in all parts of the Coast of a similar 

 nature. The tufaceous beds in the lower Miocene of Kern 

 River need only be mentioned in this connection. 



A time correlation of all these facts of disturbance, erup- 

 tions and stratigraphic discordances, etc., is obviously sug- 

 gested by the facts themselves, and it is most likely that the 

 same geodynamic action was the prime cause of them all, 

 which thus found various expression in different districts. 



Neocene Record. — With the exception of the diastrophic 

 events related in the preceding pages as intervening between 

 the Temblor and Monterey epochs, and their respective strati- 

 graphic groups, the major Neocene disturbances are fairly 

 well illustrated in diagramatic form in a former paper.' The 

 portion of the curve representing the Temblor-Monterey sub- 

 sidence should show interruption and unconformity, to some 

 extent at least, and in this respect it will conform more closely 

 to the sequence of events suggested by Dr. J. P. Smith in a 

 tabular statement giving the Neocene Sections of California.' 



This classification recognizes the main historical facts that 

 have been demonstrated in the Neocene record of California. 

 The order of events may be summarized as follows : 



1. A subsidence, possibly gradual, that led the sea 

 into the Temblor Basin, with the development of an 

 important series of deposits known as the Temblor 

 group, containing a well developed subtropical fauna. 



2. An interval of disturbance, uplift and displace- 

 ment that interrupted the continuity of sedimentation 

 in many parts of the coast. These disturbances were . 

 accompanied by considerable volcanic activity that 

 spread both basic and acid lavas and tuffs over land 

 and sea, as is especially shown about the southern 

 borders of the basin and in the neighboring districts 



1 Bull. Geol. Dept. Univ. Calif., Vol. II, p. 16. 

 2Proc. Cal. Acad. Sci., Vol. Ill, p. op. 118. 

 «Jour. Geol., Vol. 18, p. op. 226. 



December 30, 1914. 



