22 [APPENDIX 



miles beyond to the south, and at the distance of six miles the chlorite 

 slates abound. These mountains were not followed beyond this point to 

 the south, but it became evident that the trapean rocks prevailed at the 

 distance of ten or twelve miles farther on, the sharp outline of the higher 

 hills corresponding with those of a similar character observed in other 

 localities. 



To the south-east and south-west the mountains were less rugged in 

 their appearance, a considerable extent of a white micaceous granite was 

 found, OR which detached masses of sandstone were met with, containing 

 marine shells, also a conglomerate apparently of the same age. The fos- 

 siliferous rocks were much disintegrated, anci their fossils very imperfect; 

 the species observed were Pectinea and Terredina, and evidently were of 

 the same age as those in the immediate vicinity of Monte Diablo ; all the 

 other shells were so imperfect that nothing reliable was to be obtained 

 from their examination, being merely fragmentary in their character. 



To return again to the northern part of this range of mountains, and 

 in the vicinity of Monterey, we shall find that the fossiliferous sandstones 

 of this district do not compare in any degree with those above noticed, 

 but, to the contrary, all of the marine fossils of the northern part of the 

 range are found to differ in their character and relative age. On the 

 Carmello this interesting fact may be conveniently observed ; the fossils 

 are found in an argilaceous sandstone, about nine feet in thickness, and 

 rests alike on both serpentine and granitic, and has a dip of seven de 

 grees west. It is found at intervals through eleven miles of distance on 

 a course east southeast, and for a breadth of about four miles ; this for 

 mation, which must be regarded as the Post Pliocene of this country con 

 tains imbeded fossils of the genus cancer, with' casts of Cytherea, mactra 

 and tellina, all of living species in the adjoining Bay and Bay of Mon 

 terey. 



From the delicacy of the preservation of these small animals, and the 

 character of the rock in which they are imbeded, it appears evident that 

 it must have been deposited in still water, and was probably an estero 

 into which the tide ebbed and flowed regularly, with sufficient protec 

 tion to break the violence of the surf upon the coast. After its deposi 

 tion it had been gradually elevated above the surface of the waters, and 

 subsequently tilted from its horizontal position by the intrusion of igne 

 ous rocks in its vicinity. 



The cause of its disturbance and inclination is found in the intrusion 

 of a trapean dike which has cut through the granite and clay state, which 

 latter passes into a micaceous schist, and near the contact of the igneous 

 intrusion small but imperfect garnets are found imbeded. The fossilife 

 rous rocks are regularly stratified, and cleave easily in one direction ; 

 they are much twisted and contorted nearest the points at which the tra 

 pean mass broke through, but become much less curved as the distance 

 increases from that centre. A clay of fine texture and creamy color is 

 found resting on the argilaceous sandstone, and covers a large extent of 

 country stretching to the east of Monterey as far as the Toro Hills ; this 

 clay is composed almost exclusively of infusoria, apparently of marine 

 origin ; five distinct species have been observed, four of which are dis 

 coid. It is probable that they have been described either by Professor 

 Bayley, of W est Point, or Ehrenberg, as both these gentlemen have had 



