286 



B. L. CLARK THE MEGANOS GROUP 



Pi 



P 

 o 

 t-> 

 O 



m 

 o 



I? 



E.J 



D.J 



C.J 



Feet 

 Cla^\- shales aud saudstoues at top, grades dowu 

 into fine, massive, poorly indurated sandstone ; 

 exposures of tlie beds of this division are very 

 poor 0-1,500 



Sandstone of medium texture; thin-bedded near 

 bottom ; more massive at top ; yellow brown to 

 gray in color. The massive sandstones near 

 top contain lenses of harder, calcareous and 

 fossil if erous sandstones 0-300 



B. 



5. Dark slate-gray shale<> ; bedding ijlanes fairly 

 distinct ; light calcareous nodules and lenses . 



4. Sandstone, fine to coarse in texture; in places 

 forms a grit ; contains thin clay lenses ; in 

 places contains considerable carbonaceous 

 material 



3. Dark slate-gray shales, similar to (1) and (5) . 



2. Sandstone, medium to fairly coarse ; weathers 

 on surface a rusty brown ; grains chiefly of 

 quartz and mica , 



1. Dark slate-gray, clay-shale ; bedding planes in- 

 distinct ; carbonaceous material abundant . . . 



[" Coarse to medium fine, quartzitic, gray to gray- 



A.J 



brown sandstones, with some fine conglomeratic 

 layers 



Heavy conglomerates ; boulders composed of 

 quartzites, chert, limestone and large angular 

 slabs of sandstone, containing typical Chico 

 (Upper Cretaceous) fossils 



Unconformity 



0-230 



110 

 90 



50 



700 



50 



Martinez Group. . . -^j 



5. Gray-green shale 300 



4. Gray-green, glauconitic sandstone : Trocho- 



cyathus zitteli beds 50 



3. Fine-grained, gray sandstone 200 



2. Shales and sandstones 100 



1. Brown conglomeratic sandstone ; Meretrix dalli 



beds 50 



Unconformity 



Chico. 



The conglomerates at the base of the Meganos Group, division x4, 

 because of their peculiar character, are worthy of mention. Here great 

 angular slabs of fossilif erous Chico sandslone, sometimes 5 or 6 feet in 



