

42 [APPENDIX 



** ** t A %^tf& t ' v < 



terrace between the upper level, or that of the plain before the rise 

 $l%an. 



A terrace slope may thus be formed by a gradual elevation, and also 

 without any intermission in the process, there might be intermediate ter 

 races in some parts of, the same region. A river terrace then, in an 

 alluvial district cannot be considered an evidence of abrupt elevation of 

 country in which it is found, the more especially if a uniform slope is 

 found upon its surface. 



The district south of San Francisco in which extensive valleys are to 

 be found comport themselves in all general features with those found on 

 the Sacramento and thence into Oregon. On the .south part of the San 

 ta Clara Valley, beyond the ranch of Cruz Cervantes, the terraced' form 

 of the. valley is clear and distinct; in this place there were but two of 

 these flats observable that through which the-rSan Benito flowed, had 

 a rise of nine feet above the level of the creek, while the higher terrace 

 to the east rose very abruptly eighty -five feet above the former. The 

 surface level had an inclination of twelve degrees vfrom the base of the 

 Santa Anna Mountains towa/ds the west ; the river flowed upon the 

 western side of the valley entirely. 



tTwo successive terraces were foimd on the Pajaro, the upper one still 

 retains the marks of tide water upon its surface. 



The Salinas Valley exhibits the terraced form in a marked degree, 

 and its inclination of surface from the east toward the west corresponds 

 very closely with that just noticed as occurring on the south part of the 

 Santa Clara and San Juan. The number of terraces on this valley are 

 three, and have a varying width of three to five miles, the slope of each 

 surface is gentle and smooth' throughout the entire length of the plain. 

 It differs from the Sacramento or San Joaquin in having but one' line of 

 -inclination or dip, the others "nave a dip from each border toward; their 

 centre, thus giving them their basin-shaped structure. The slope of the 

 Salinas appears to have been acquired from the recent volcanic agency 

 that formed the Santa Anna Mountains, and those to the north as far as 

 Pacheco's Peak ; on examination it is found that the dip of all the sedi 

 mentary or stratified rocks of this part of the country correspond in 

 direction, and that the dip decreases as the distance from that centre in 

 creases. The Post Pliocene rocks of the Carmello were disturbed at 

 this time, and the entire range of sedimentary rocks of recent date, 

 throughout the Coast Mountains in this section of the country have suf 

 fered in a similar manner, and undoubtedly from the same cause. 



From the peculiar features manifested in the formation composing the 

 Coast Mountains, as noted in the preceding pages, and the more recent 

 causes of disturbance whicti have acted in this part of the range, as is 

 found in the modifications of level extending through the valleys above 

 noted, and the intervening mountains between these valleys ; it will ap 

 pear very doubtful that any formation containing mineral coal will be 

 found. The forces that have acted on this part of the county and have 

 elevated the different rocks found on the mountain sides, have as yet 

 developed no member of the secondary series, in which the coal forma 

 tions are found ; but like the mountains to the north, both in the Sierra 

 Nevada and Coast Mountains, nothing above the primitive is to be seen, 



