84 University of California Publications in Geology [Vol.9 



The larger streams show evidences in the lower valleys of at least 

 three periods of terracing, perhaps largely due to aggraded streams. 

 Although in the region to the north, as at Domengine Creek and 

 Cantua Creek, there are evidences of far higher terraces, in the region 

 where the vertebrate remains are found there are now no evidences 

 of terraces and if terrace deposits were ever present they are now 

 completely removed from the bare outcrops of Btchegoin strata. None 

 of the terrace material characterized by fragments of Ostrea titan 

 Conrad and Pecten estrellanus Conrad brought from the Santa Mar- 

 garita and none of the red and black pebbles brought from the Chico 

 are here present. At one locality several horse teeth were found near 

 the top of a sharp hill with very evident outcropping strata of a 

 compact resistant shale. It seems odd that, if general terracing of the 

 region has taken place and nearly all of the deposits have been removed, 

 we do not find this fauna upon the lower part of the Etchegoin or at 

 the localities in the Jacalitos which are of no greater elevation. On 

 the contrary, the bone fragments in some places seem to occur along 

 zones, following the outcropping strata, and collecting could be done 

 with success only by following these beds. 



Summary 



As has been stated, the faunal zones of the Etchegoin correspond- 

 ing to similar zones in the southern part of this district appear to 

 occur here in the type section of the formation. The uppermost 

 of these corresponds to the Mya zone, which in the Kettleman Hills 

 is immediately below the Tulare formation. Hence we apparently 

 have exposures of the complete Etchegoin section in this area. Near 

 the base of the Etchegoin an unconformity has been found which 

 perhaps may prove to be of some importance when a wider and more 

 careful study has been made. Vertebrate faunal zones have been found 

 in both the Jacalitos and Etchegoin formations. These have a relation 

 to the invertebrate faunal zones that tends to throw light upon the 

 interrelation of the two faunal time-scales of the Pacific Coast. As 

 shown by the studies of Professor Merriam, " the evidence seems to 

 indicate that the invertebrate horizons referred to the upper Miocene 

 and lower Miocene have been placed somewhat lower than the cor- 

 responding horizons of the eastern part of this continent and of 

 Europe. 



o Merriam, J. C, Tertiary Vertebrate Faunas of the North Coalinga Eegion, 

 Trans. Am. Philos. Soe., vol. 22, part 3, Philadelphia, 1915 



