192 QUICKSIIA'KU DEPOSITS OF THE PACIFIC SLOPE. 



are composed of the metamorphic rocks. I believe no one could examine 

 this locality without being convinced tliat the Wallala beds rest unconform- 

 ably upon the metamorphic, nor could any one pass inland from the mouth 

 of the Russian River to Knoxville without feeling sure that the metamorphic 

 is uniform in character and substantially continuous, though occasionally 

 masked by eruptive rocks and possibly b}^ a few patches of unaltex'ed stratn. 



There is, furthermore, much indirect structural evidence that a non- 

 conformity must exist between the Knoxville beds and the Chico. Some- 

 where between the end of the Knoxville and the beginning of the Miocene 

 there was a great upheaval, accompanied by siliceous and magnesian 

 metamorphism and followed by enormous erosion, for at many points the 

 unaltered Miocene clearly rests unconformably upon the metamorphic rocks. 

 This I have observed on San Bartolo Creek and in the valley of the San 

 Benito, to which the other is tributary, and there is evidence of similar 

 relations at Mt. Diablo and at New Almaden. Professor Whitney found the 

 Miocene resting uncomforraably upon the metamorphic bet\\een the Guada- 

 lupe mine and Forbes's mill, and also near McCartj-sville,' as well as north 

 of the Golden Gate,^ for instance, near Tomales,^ while, in speaking of the 

 neighborhood of Suscol, he says:* " It is probable that the most extensive 

 disturbances of the Cretaceous, as also the larger portion of the metamorphic 

 action upon it, had taken place before the Tertiary marine and volcanic 

 beds were deposited." 



If this non-conformity does not occur between the Knoxville and the 

 Chico, it must be sought between the Chico and the Tejon or between tlie 

 Tejon and the Miocene. The stratigraphical relations at New Idria and at 

 Mt. Diablo show that there was continuity of sedimentation from the Chico 

 to the Tejon and the organic remains prove that there was continuity of 

 life. The great non-conformity cannot, therefore, have been between these 

 groups. Between the Tejon and the Miocene there is at least no general 

 non-conformity.^ Near New Idria and at Mt. Diablo, for example, the Mio- 



' Geol. Survey California, Geology, vol. 1, p. 69. 

 2 Ibid., p. 79. 

 ■'Ibid., p. 83. 

 « Ibid., p. 10:5. 



■^Professor Wliitncy (Aiir. Giav., p. 'Jfi) writes: "Tbe Miocene aud the Cretaceous secui every win re 

 to be cuufiirnKilile willicucb oilier."' The Crelacecus hero rcfi-ned to is of course the Tf'jon. Jlr. J. 



