190 University of California Publications in Geology [Vol. 13 



A fossil was found by Mr. D. D. Bailey of Julian in the small area 

 of metamorphic rock that lies in the granite about a mile southeast 

 of Banner. This was submitted by Mr. H. L. Huston of San Francisco 

 to Dr. J. P. Smith, who pronounced it "a slender ammonite that is 

 without much doubt Triassic." 11 



The fossil is an imprint of an ammonite on the surface of an 

 angular pebble of dark gray, quartzitic rock. It was found as float. 

 The writer in company with Mr. Bailey visited the locality where this 

 was found. The rocks of the vicinity are non-fissile, quartz-two-mica 

 schists, sillimanite gneiss and blue-gray quartzite. Several hours' 

 search was not rewarded by the finding of any fossils, but consider- 

 able rock similar in appearance to the matrix of the fossil specimen 

 was seen. 



Correlation based on Uthologic character. — The conclusion has 

 already been presented that the Julian schists were originally a series 

 of shales, fine clayey sandstones, and pure quartz sandstones. The 

 beds of the Santa Ana Mountains, as described by Mendenhall, would, 

 if subjected to further metamorphism, yield schists much like those at 

 Julian. 



The writer has examined the metamorphic rocks along Railroad 

 Canon, north of Elsinore in Riverside County, which were referred 

 by Mendenhall to the Triassic on the basis of their lithologic similarity 

 with the rocks of the Santa Ana Mountains. The prevailing rocks are 

 dark slates and gray quartzites. Both a white and an impure facies 

 of quartzite was seen and some of the slates are rather sandy. Within 

 this series at one horizon occur gray cherts interbedded with green 

 shales. Lenses of fine-grained quartz-rhodonite-rhodochrosite rock are 

 found lying parallel to the bedding within this sequence of chert layers. 



Similar occurrences of manganese minerals in chert lenses inclosed 

 in small masses of metamorphic rocks which are in turn surrounded 

 by granite are found a short distance northeast of Deer Park, and 

 between Campo and Jacumba, in San Diego County. In these lenses 

 metamorphism has been more severe so that rhodochrosite is lacking 

 and manganese garnet occurs in addition to rhodonite. Moreover, the 

 inclosing rocks are quartz-mica schists similar in appearance to the 

 Julian schist. If these manganese-bearing cherts really belong to the 

 Julian schist series, it is seen that there is a remarkable similarity 

 between that series and the Railroad Canon rocks. Practically the 

 only difference is in the degree of metamorphism. 



11 Oral communication. 



