394 



University of California Publications in Geology [Vol. 8 



Mr. W. P. Jones, 14 in a paper entitled "The Geology of the Sargent 

 Oil Fields," described an area just to the southeast of the Santa Crnz 

 quadrangle. In this paper he states that the Monterey shales (Lower 

 Neocene) are unconformably overlain by the San Pablo. The fauna 

 collected at the base of this so-called San Pablo contains species that 

 are characteristic of the Etchegoin or Lower Purisima. Such species 

 as Echinarachnius gibbsii, Pecten ivattsi, Peeten oweni, Mytilus 

 coaling ensis, Glycimeris coaling ensis, Thais Tcettlemanensis, etc., are 

 very abundant in these beds. As will be shown later, the fauna of the 

 Etchegoin is believed to be very distinct from that of the San Pablo 

 and much younger, being separated from it by a considerable time 

 interval. 



To the south of the Sargent oil fields very little is known about the 

 formations of the upper Neocene until Salinas Valley is reached. The 

 type section of the Santa Margarita formation (which is equiva- 

 lent to the San Pablo Group to the north) as described by Dr. H. W. 

 Fairbanks, 15 is near the south end of Salinas Valley in the vicinity of 

 the town of Santa Margarita, San Luis Obispo County. Here the 

 Santa Margarita rests unconformably on the Monterey shales (Lower 

 Neocene). The desposits are known to extend fairly continuously 

 along the north flank of the San Jose Range to the southeast of 

 Salinas Valley, connecting with the beds mapped as Santa Margarita 

 in the McKittrick District and along the south and west sides of the 

 San Joaquin Valley. 



It is interesting to note that Dr. Fairbanks, 10 in his first description 

 of these beds, correlated them with the San Pablo of Middle California 

 and gave to them that name. Later, in the San Luis Folio, the name 

 was changed to Santa Margarita. On the maps of the folio Santa 

 Margarita is used as a local formation name and in the text the author 

 refers the formation to the San Pablo Group. 



« Univ. Calif. Publ. Bull. Dept. Geol., vol. 6, no. 3, pp. 55-78, 1911. 

 is San Luis Folio, No. 101, p. 10, 1904. 



is Fairbanks, H. W., The stratigraphy of the California Coast Eanges, Jour. 

 Geol., vol. 3, no. 4, 1903. 



