stanton.] NORTHERN UTAII. 45 



should be strictly correlated with the Dakota sandstone east of the 

 Eocky mountains seems to me doubtful. 



In a previous paper l already cited, I have shown that in western 

 Wyoming the brackish water Bear River formation, formerly called the 

 Bear River Laramie, is beneath the Colorado, and that it rests on just 

 such a series of shales, sandstones, and conglomerates as is included in 

 No. 4 of the Rockport section. llie nearest locality at which Bear River 

 fossils have been found is the well known one on the Union Pacific 

 railroad near the mouth of Sulphur creek, which is about 40 miles from 

 Rockport. The lowest strata there exposed are the upper part of the 

 Jurassic. 



The detailed sections as seen in various exposures in the immediate 

 neighborhood of Sulphur creek maybe thus epitomized in ascending 

 order : 



Feet. 



1. Reddish brown, and bluish shales and slialy sandstones with a thin cal- 



careous band about the middle containing Belemnites dcnsus, Trigonia 

 quadrangnJaris, and Pleuromya webcrcnsis. Thickness about 500 



2. A heavy bed of brown pebbly conglomerate forming the base of a series 



of alternating coarse sandstones, and variegated shales that was doubt- 

 fully referred to the Dakota. Total thickness 1, GOO 



3. Very fossiliferous dark calcareous shales with a few thin beds of sand- 



stone. Fossils: Pyrguhfera humcrosa, Corbicula durleei, Unio vetustus, , 

 Corbula pyriformis, etc 840 



4. Blue and brownish fissile shales with many scales of fishes, a few frag- 



ments of Ammonites and, at a higher horizon, numerous specimens of 

 Cardium paupcrcul urn. Some beds of sandstone are probably included. 



Thickness estimated 1,000-1,500 



5. At a higher horizon, the exact position of which could not be determined in the 

 local sections on account of faults, a sandstone accompanying a coal bed yielded 

 Inoceramus labiatus, Corbula subirigonalisf, Donax cuneata, Pugnellunfuviformis, Ostrea 

 soleniscus, and other species that permit its correlation with No. 4 of the Coalville 

 section. There are also higher beds exposed here, but owing to the complicated 

 structure the upper part of the section has not been worked out. 



No. 1 is Jurassic, and it is comparable with Nos. 5 and 6 of the Rock- 

 port section. 



No. 2 is very much like No. 4 of the Rockport section. The conglom- 

 erate at the base is of the same character at both places, though near 

 Sulphur creek it reaches a thickness of 150 feet, while at Rockport it is 

 broken up into several thinner beds, the thickest of which is about 50 

 feet. 



No. 3 is the Bear River formation with its characteristic fossils here 

 ranging through only 650 feet of strata, but at other localities farther 

 north the fossils were found to range through athickness of at least 2,500 

 feet, extending down almost to the conglomerate at the base of No. 2. 

 The failure to find Bear River fossils at Rockport and in East canyon 

 may be due to the incomplete exposures of strata there, as the por- 



.' Am. Jour. Sci., vol. xliii, 1892, pp. 98-115. 



