Lawson.] 



Geology of Carmelo Bay. 



29 



thickness is over 1,000 feet. Farther up the Carmelo River, how- 

 ever, the greater height of the hills, taken together with the gently 

 inclined attitudes of the strata, indicate a total thickness for the 

 series of not less than 2,000 feet. The structural features of the 

 series are of a simple character. As above stated, the strata as a 

 rule are gently inclined to the horizon, and in places they are quite 

 flat. Locally, however, there may be observed evidence of sharper 

 flexure, as in the vicinity of the highest point on the coast road 

 between Carmelo Bay and Monterey, where the dip for a short 

 distance is at high angles and variable in direction, as if in the vicin- 

 ity of a line of dislocation. The amount of disturbance which has 

 affected the Monterey series is much less than that which is appar- 

 ent in the case of the Carmelo series, as is evidenced by the absence 

 of the minute shearing and the sharp, vertical folding which occur 

 in the latter. This fact, and the equally significant one that the 

 Carmelo rocks have been locally, completely eroded from the granite 

 before the deposition of the shale of the Monterey series, so that 

 the latter rests directly on the granite, serve to establish an uncon- 

 formity between the two series, although they have not been 

 observed in direct contact. 



ERUPTIVE ROCKS. 



Variation of Character. — The eruptive rocks in the vicinity of 

 Carmelo Bay, although occurring in several separate areas, have a 

 certain common feature which serves to stamp them as genetically 

 identical, and their field relations in the different areas point to a 

 single period of eruption. They exhibit, however, a considerable 

 variation of character. Thus, in the same area, we may have the 

 rock at one place perfectly massive and compact, and at another 

 only a few hundred yards distant it will be found to be exceedingly 

 vesicular or amygdaloidal, with amygdules occasionally two inches in 

 length. In some cases a very pronounced flow structure is appar- 

 ent, and in others no such structure has been developed. In some 

 localities there is a distinct lamination of the rock, accentuated by 

 contrasting colors, while in the same mass not far distant no lamina- 

 tion is apparent. There is also an extensive range of aspect due to 

 the varying degree to which weathering influences have affected the 



