SMITHSONIAN MISCELLANEOUS COLLECTIONS 





^C4 .:JtlJ 







BA 



I'liCdiifiiniialile contact on line (_-/«) lietween Archean (F = Vishnu series) and Algonkian ( L'';; =^ L'nkar seriei 

 leniuved latter tip left over Archean before deposition of the Cambrian (r = Tapeats sandstone). The unconforir 

 the Algonkian (r;; = Unkar) series elsewhere on plate; more fully shown in plate 4J. 



Locality: North side of (irand Canyon of Colorado River, Arizona, opposite Grand \'iew trail. This is wb 

 .Archean at A. (American Jour. Sci., 3d ser., Vo\. 26, 1883, p. 4.3S, third paragraph.) 



