TOPOGRAPHY OF THE PACIFIC COAST. 4 1 



Tertiary period, that is, that they have been forming since the 

 beginning of that epoch. ^ . . . The evidence of the geological 

 age of the gravel deposits afforded by the plants found in the 

 sedimentary beds underlying the latest eruptive masses in the 

 mining region of the Sierra has already been discussed by Mr. 

 Lesquereux. He distinctly recognizes the presence in this flora 

 of forms identical with or closely allied to those of the Miocene; 

 but still calls the age of the group Pliocene. Something of the 

 same kind seems to be legitimatel}^ inferred from the animal 

 forms of the same deposits. There are certain fossils which have 

 been found only in deep-lying gravels like those of Douglas 

 Flat and Chili Gulch. No traces of the rhinoceros, the elothe- 

 rium or the small equine animal referred with doubt by Leidy 

 to Merychippus have ever been found in deposits which could 

 by any possibility be proved to be more recent than the basaltic 

 overflow. It is true that the evidence thus far collected is but 

 fragmentary. Still, taking it for what it is worth, it may be said 

 that the affinities of these animals found in these lower deposits 

 would indicate a Miocene rather than a Pliocene age. There 

 are also, it is believed, stratigraphical reasons for admitting 

 that some at least of the deposits containing these older fossils 

 may be proved by other than palaeontological evidence to belong 

 to an older series than those strata which, though anterior to the 

 basalts, yet contain a fauna decidedly mere Pliocene than Mio- 

 cene in character." 



A collection of plants made from the older auriferous gravels 

 upon the northern end of the Sierra Nevada was examined by 

 Professor Lesquereux, who reported that their relation is evi- 

 dently to the Miocene (U. S. Geological Survey, Eighth Annual 

 Report, p. 419). Professor L. F.Ward, who examined the same 

 collection, agreed that they were Miocene, most likely upper 

 Miocene. 



Recently the evidence afforded by the plant remains has been 



' By the Geological Survey of California the Tejon was regarded as Cretaceous. 

 Palaeontology, Vol. 2, p. xiii. It is now regarded as Eocene, and in Oregon lies uncon- 

 formably on the Shasta-Chico series. 



