ELEVATION AND GROUPING OF THE COAST RANGES. 27 



Sacramento, San Joachin, and Tulare valleys, all naturally one ; originally elevated in one 

 mass without much difference of level, it has since then undergone an elevation both at its 

 northern and southern ends, raising it several hundred feet upwards at each extreme, and 

 throwing the flow of its waters to the middle, where they would have accumulated and formed 

 an inland basin sea, had not the same upheaval extended itself to the Coast Eange, and by 

 depressing these in the latitude of San Francisco and crushing the fractured edges together, 

 left a chink through which the ocean might have found its way inward, and the inland drainage 

 outward, whose long continued action at last wore for themselves the wide channels and basins 

 of Suisun, San Pablo, and San Francisco. The same upheave which produced this alteration 

 of level of Sacramento and Tulare valley, would also have raised each of the valleys to a 

 higher level at their southern than at their northern end, and this is found to be uniformly so. 

 The Salinas, Estrella, Santa 5K,ria, Santa Clara, and every other valley (Estero excepted) slope 

 northwards ; even the open plains, such as those of Los Angelos and San Bernardino, are higher 

 at the southern than at the northern end. 



These considerations would lead to the belief that the commencement of upheaval and the 

 point of divergence was south of latitude 34°. In that vicinity is the loftiest area of any extent 

 south of San Francisco ; and, as eruptive forces are most powerful at or near their commence- 

 ment, we must conclude that the final elevating forces initiated in the south and travelled 

 northward. Subterranean reactions are now going on with more intensity in the south than 

 in the middle or north. Earthquakes are more frequent ; warm springs, acid vapors, and 

 bituminous exudations abundant. Indeed, the force is at present actively exerted at sea, 

 southwest of the islands off Santa Barbara shore, throwing up immense quantities of bitumen 

 in the oleaginous and semi-fluid condition. These islands themselves are the result of such 

 forces exerted ; and so far from viewing this portion of California as a sinking continent, it is 

 more in accordance with geological facts to consider them as the dawn of a new land, which, 

 when fully elevated, will have its mountain ridges and intervening valleys, like those of San 

 Luis Obispo and Santa Barbara counties ; its sandstones, argillites and bituminous shales ; its 

 lofty terraces and elevated sea beaches, like its predecessors ashore. 



Having dwelt thus much on the character and age of the several ranges known as the Coast 

 Mountains, it only remains to notice somewhat in detail their direction or trend. A few of 

 these ranges are not continuous, but drop down into high rolling land for a few miles, rising up 

 again and pursuing the same direction. This is very common in the granite ranges. Some of 

 *he serpentine ranges have their continuity only indicated by an elevated butte, which may be 

 connected by the compass with its congener several miles apart. It is probable that at a 

 former period these chains were more connected as a whole, and have since suffered from the 

 effects of extensive denundations, their detritus forming the local conglomerates. The ranges 

 may be enumerated in the order commencing at the east and passing westward — thus the range 

 most eastward would be — 



Division 1. — Granitic. 

 Group 1. — Gavilan, or Monte Diablo range. — This forms the boundary between Tulare valley 

 and the coast. It may be traced from the Agua de Paleta, near the Caiiada de las Uvas, to 

 the Gavilan Mount, in Monterey county, southeast of the bay. In its course it forms the eastern 

 limit of Estero plain, the elevated lands of Carizo and Panza, and the eastern border of the 

 Salinas valley. It is a coarse felspathic granite in its northern, and porphyritic in the southern 

 terminations. Its general direction, north 45° west. 



