58 SEDIMENTARY GROUPS OF THE PLATEAU PROVINCE. 



No. 13, 750 feet. Very compact, bluish-drab limestone, containing 

 numerous seams of chalcedony. 



No. 14, 150 feet. Purplish and drab argillaceous shales. 



No. 15, 225 feet. Buff limestone, not well exposed. 



No. 16, 300 feet. Limestone and sandstone, thinly bedded ; only upper 

 members exposed. 



LODOKK GKOUP. 



No. 17. 465 feet. Thinly bedded sandstones, lying unconformably on 



the Uinta Group. 



CATARACT CANON SECTION. 



By J. F. STEWARD. 

 UPPEE AUBREY GEOUP. 



No. 1, 150 feet. Friable, buff colored, homogeneous sandstone. 



No. 2, 450 feet. Red sandstone, thickly and thinly bedded. 



No. 3, 105 feet. Fine grained sandstone, ending in a foot of very 

 brown, shaly sandstone. 



No. 4, 95 feet. Brownish-buff sandstone. 



No. 5, 25 feet. Compact, bluish-drab limestone, containing Productus 

 nebrascensiSj Aihyris subtilita, crinoidal stems, nodules of red chert, &c. 



No. 6,210 feet. Mostly massively bedded, coarse sandstone, almost a 

 conglomerate at top, but gradually becoming fine textured ; dark red and 

 shaly at base ; Belleroplion. 



No. 7, 4 feet. Hard, compact, dark blue limestone. 



No. 8, 6 feet. Fine buff sandstone. 



No. 9, 50 feet. Blue limestone, divided into three parts by arenaceous 

 members. 



No. 10, 92 feet. Drab sandstone, very coarse at top, but becoming fine 

 at base. 



LOWEE AUBEEY GEOUP. 



No. 11, 721 feet. Sandstone and limestone in alternation. 

 , 70 feet. Drab, compact limestone, containing in great numbers Allo- 

 risma, Myalina, &c. ; also a large Pleurotomaria. 



b, 12 feet. Fine grained, light gray sandstone, very friable. 



c, 3 feet. Compact limestone, same as a. 



