.0                                                                              
 SEDIMENTARY, METAMORPHIC, AND IGNEOUS ROCKS OF PRECAMBRIAN AGE                 
                                                                                
                        SEDIMENTARY ROCKS                                       
Yu     UINTA MOUNTAIN GROUP (AGE 950-1,400 M.Y.)--Quartzite, conglomerate, and  
         shale                                                                  
YXu    UNCOMPAHGRE FORMATION (OLDER THAN GRANITES OF 1,400-M.Y. AGE GROUP AND   
         YOUNGER THAN GRANITES OF 1,700-M.Y. AGE GROUP)--Quartzite, slate, and  
         phyllite                                                               
                                                                                
            METAMORPHIC ROCKS (Age 1,700-1,800 m.y.)                            
Xb     BIOTITIC GNEISS, SCHIST, AND MIGMATITE--Locally contains minor           
         hornblende gneiss, calc-silicate rock, quartzite, and marble.  Derived 
         principally from sedimentary rocks                                     
Xfh    FELSIC AND HORNBLENDIC GNEISSES, EITHER SEPARATE OR INTERLAYERED--       
         Includes metabasalt, metatuff, and interbedded metagraywacke; locally  
         contains interlayered biotite gneiss.  Derived principally from        
         volcanic rocks                                                         
Xq     QUARTZITE, CONGLOMERATE, AND INTERLAYERED MICA SCHIST                    
                                                                                
                    Age probably >2,500 m.y.                                    
Wr     RED CREEK QUARTZITE--Metaquartzite, amphibolite, and mica schist.        
         Present only in small area at Utah border in Uinta Mountains