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CORDILLERAN MESOZOIC REVOLUTION.
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conditioned the uplift and wide-spread disturbance which is freely recognized in geological literature as having occurred at the close of the Jurassic. Again we have, as in British Columbia, a wonderful dissolving of the ancient status quo, a revolution of no mean import, whether regarded merely as an historical event or in its bearing upon the general principles of epeirogeny. The important feature which distinguishes the group of facts observed in the Sierra Nevada from those in British Columbia is that in the former we have the Jurassic a part of the great assemblage of rocks invaded by the granite while in British Columbia these rocks are not known to exist. This difference, taken together with the probable fact that the pre-Cretaceous denudation of the Sierra was less profound than that of British Columbia, suggests a progressive development of the batholitic condition from north to south, so that the disturbance was felt somewhat later in California, although it was part, doubtless, of the same great subcrustal process.

In the Coast Ranges of California we have much less precise information than in the case of the Sierra Nevada. Analogous conditions seem to be indicated by the information at hand. There are areas of granite and metamorphic rocks which have been subject to great denudation prior to the deposition of the Cretaceous. No rocks of older age than Cretaceous are known to rest upon the worn surface of this complex. Carboniferous fossils have recently been found by Mr. Fairbanks in the Santa Ana Range[1] in a series of rocks into which the granite of the region has been injected. The same geologist informs us of the intrusion of the granite of the Gavilan Range[2] into the Coast Range metamorphics, and of similar relations in the Trinity Mountains in the Northern part of the state.[3] The writer, also, has observed that the granite of the Santa Cruz Range is intrusive in the limestone of the metamorphic complex. Mr. Fairbanks is of the opinion that generally the

  1. ↑ Am. Geologist, vol. xi., Feb., 1893.
  2. ↑ Loc. cit.
  3. ↑ Am. Geologist, March, 1892.
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