EXPLANATION OF PLATE 35 



Fig. A. Monterey chert, showing weathering of chert to white shale. Note 

 the alteration to white shale along fissures. 



Fig. B. Monterey chert, showing unconformity in the lamination of the 



chert. 



Fig. C. Monterey chert, showing weathering of black flinty chert to white 

 shale. The base of the specimen is approximately parallel to the plane of bed- 

 ding. Notice the manner in which the alteration transgresses the bedding. 



Fig. D. Weathering of black flinty chert to white shale. Notice the trans- 

 gression of bedding by the alteration. Notice also the development of white 

 bands on the weathered surface. 



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