898 H. W. TURNER — GEOLOGY OF MOUNT DIABLO. 



tufas and conglomerates. The locality is on the northern side of Corral 

 hollow, and was first investigated by the state geological survey,* whose 

 officers collected here fossil leaves, supposed by Professor Whitney to be 

 Pliocene. 



Professor Lesquereux, in his " Cretaceous and Tertiary Floras," forming 

 volume VIII of the monographs of the Hayden survey, gives the following 

 species from Corral hollow, presumably collected by the California state 

 survey : 



Equisetum, sp. und. ; 



Sequoia angudifolia, Lx. ; 



Taxites olriki, Heer ; 



Alnus corrallina, Lx. ; 



Castanea imgeri, Heer ; 



Salix Integra, Goepp ; 



Populus balsamoides, Goepp ; 



Plantanus dissecta, Lx. ; 



Laurus princeps, Heer ; 

 " grandis, Lx. ; 

 " salicifolia, Lx. ; 

 " californica, Lx. ; 



Cinnamomum affine, Lx. ; 



Myrtus oregonensiSy Lx. 



These are, however, referred by Lesquereux to the Miocene, as also are 

 the following, collected by myself if 

 Laurus californica, Lx. ; 

 " resurgens, Sap. ; 

 " furstenbergi, Heer ; 

 Per sea pseudoearolinensis, Lx. ; 



" punct'ulata, Lx. ; 

 Rhus henfleri, Heer. 

 It will be noted that two species of Laurus are common to the two locali- 

 ties. Corral hollow and Kirker pass. 



The geological evidence that these beds (composed largely of andesitic 

 detritus at the three localities named) are of the same age is so strong, and 

 the evidence of the marine shells in favor of their Pliocene age is so definite, 

 that it would seem most logical to regard them so, notwithstanding the 

 Miocene aspect of the flora, of which one species (Magnolia californica, Lx.) 

 has at another locality (Chalk Bluff's, Nevada county, California) been re- 

 ferred by Lesquereux himself to the Pliocene. 



The four terranes just discussed, namely, the Chico, Tejou, Miocene, and 



♦Geology of California, vol. I, 1865, p. 38. 

 tProc. U. S. Nat. Museum, vol. 11. 1889, p. 25. 



