30 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Disturbances noted elsezvhere. — Reviewing briefly some of 

 the corroborative evidences of wide-spread disturbances in 

 early Miocene time attention may be called to the following: 

 1904, H. L. Haehl and Ralph Arnold showed that eruptions 

 of diabase and basalt took place during the early Miocene. We 

 read : "The diabase breaks through beds of lower, and per- 

 haps middle, Miocene age ; while the associated diabase tuff is 

 interbedded with strata containing a typical lower Miocene 

 fauna and lies below the Monterey shale. The basalt outflow 

 exposed near Stanford University overlies and metamorphoses 

 beds of lower Miocene age, and is overlain by beds containing 

 a fauna very similar to the underlying strata. This evidence 

 indicates the lower Miocene age of the basalt and its probable 

 contemporaneousness with the diabase of Mindego and Lang- 

 ley Hills".^ 



These facts are in accord with the unconformity shown in 

 the discordance of dips between "Monterey strata and those 

 of the Vaqueros sandstone" described in the same district." 



Attention may be called here to the intrusion of diabase into 

 the Temblor beds of the San Juan district. 



In the vicinity of Edna, and south of San Luis Obispo, 

 Temblor beds are found overlaid with thick strata of rhyolite 

 tuff, and this in turn is covered by a greater thickness of Mon- 

 terey shales. With the exception of the Temblor (Vaqueros) 

 beds these facts are well represented on the geologic sheet of 

 the San Luis Folio. However, the Temblor beds are well ex- 

 posed with many characteristic fossils directly south of San 

 Luis Obispo and east of the creek of the same name. On the 

 geologic sheets these Temblor beds are represented as Monterey. 

 However, as they contain Turrit ella inezana Conrad, Pecten 

 magnolia Conrad, Conus hayesi Arnold and Dosinia ivhitneyi 

 Gabb, the lower Miocene (Temblor) age need not be ques- 

 tioned. It is not unlikely that these rhyolite beds are genetic- 

 ally connected with eruptions of considerable magnitude that 

 have occurred about San Luis Obispo. These beds of tuff 

 extend in a south-easterly direction toward Santa Maria and 

 beyond, and are covered by beds of siliceous shales, as they 

 are near San Luis Obispo. 



1 Proc. Am. Philos. Soc, Vol. 43, p. 18. 

 ^ Santa Cruz Folio, descrip. text, p. 4. 



