15 



* 



have I as yet been able to detect the slighest vestige of organic life, and from 

 those who have succeeded me in the examination of these rocks, I learn that 

 they have met with no better success. 



It is not uncommon to find impressions of marine plants at least, in rocks of 

 this character, but even these are absent in the group under consideration. 



A distinguishing feature in these limestones, is the small proportion in mass 

 which they bear to the other primitive rocks with which they are associated and 

 invested, and when found in contact, (as was the case in two instances) with the 

 more recent igneous intrusions, their structure was found materially changed. 

 They were more often found imbedded in the granitic rocks than in any other po 

 sition ; but little of the entire line of beds possessed a fine crystalline texture, 

 and this even was usually much discolored by iron. 



The limestone rocks of these mountains are well represented on the west flank 

 of the Sierra Nevada, their equivalents may be found in various mining locali 

 ties, as at the Marble Springs, Sonora, Ringgold, Murderer's Bar, Carson River 

 Falls, also as far north as the county of Pluruas, it passes through all the inter 

 mediate counties lying between Mariposa on the south and Plumas on the north. 

 In some of the above localities it has been found to answer the purpose of a 

 good building material, this however is merely local, but its principal use in this 

 State is the manufacture of lime. 



The granitic series probably underlies the entire central and a large portion 

 of the eastern line of ridges, although it does not make its appearance upon the 

 surface to that extent which this supposition would seem to imply. I am satis 

 fied of this fact however, from the examination of the debris found in and about 

 the small streams, which are found traversing some of the deep canons of these 

 mountains ; in all the sedimentary beds, of sand and drift thus found, the gran 

 itic constituents of the same formed by far the greater proportion, and it may be 

 said constituted their entire mass. How far this formation may extend west 

 ward, or towards the coast, and north of the San Bernardino is yet quite un 

 certain, as I am not aware of any outcrop of the granite north of this chain 

 and south of San Simeon. 



TERTIARY ROCKS OF THE COAST MOUNTAINS. 



The tertiary rocks of this part of the coast mountains, are interesting in a 

 scientific point of view, in directing our attention to those periods of the earlier 

 history of this portion of the western continent, when it was submerged be 

 neath the waters of the ocean. The prevalence of the tertiary rocks in these 

 mountains fully corroborates all that has heretofore been said respecting almost 

 the entire range of country stretching from the base of the eastern Sierras to 

 the present eastern confines of the sea. On the summits and sides of the hills, 

 we find the fossiliferous rocks of this part of the country, maintaining the same 

 relative positions which they occupy in other and distant parts of the State; the 

 equivalents of the Monte Diablo groups are found as well marked as at any 

 part of that particular range, while at the same time we find in this connection 

 other beds of widely different forms, and belonging to different periods of the 

 same era, and which are found again hundreds of miles distant in other direc 

 tions. 



Sufficient is now known respecting the distribution of the vertebrate and in 

 vertebrate animals inhabiting the country during these remote ages, that we are 

 able to frame, at least, an approximate opinion of the relative periods at which 

 the different classes of animals existed, whose remains have been found within 

 the limits of this State. 



