GEOLOGICAL SURVEY OF THE TERRITOEIES. 447 



itous exposures a stratified appearance. The coloring- matter by which 

 tlie whole formation is tinged brownish-red evidently comes from these 

 intercalated seams of sandstone, and the same material forming tJie 

 paste of, the conglomerate; because the pebbles and bowlders them- 

 selves forming the main body of the same, when washed, often retain 

 little of this ferruginous tinge. 



Of course we can scarcely hope to find organic remains in such a for- 

 mation as this, which must have been deposited by the action of ])owerful 

 currents of water, in which mollusks or other organisms could not have 

 lived ; and if, by any chance, their shells or other solid parts should 

 have been placed there, they would probably have been ground to pow- 

 der by attrition among the rolling pebbles and bowlders and whirling 

 sands. If any traces of fossils, however, exist in any i)art of this forma- 

 tion, it is among the seams and intercalated beds or lenticular masses 

 of sandstone, or local bodies of finer material, that they most probably 

 occur. 



This immense massive conglomerate not only composes the towering 

 walls of Echo Canon — at places forming perpendicular, or even over- 

 hanging escarpments, oUO to 800 feet in height — but also rises into 

 mountain masses on the west side of Weber River near the mouth of 

 the canon. Opposite Coalville, on the same side, five miles farther up, 

 it likewise forms the upper part of the mountains above the Cretaceous; 

 while south of Coalville, on the east side of the river, it is developed in 

 such great force as apparently to form much of the entire mass of the 

 mountains seen there. I am not sure that we saw its entire thickness 

 exposed at any one place, but it probably attains a thickness of 2,000 

 feet in places. 



That this great conglomerate formation is of Tertiary age, as suggested 

 by Dr. Hayden, Mr. King, and Mr. Emmons, I know of no reason to ques- 

 tion. This view not only accords with the fact of its position above such 

 an extensive series of Cretaceous rocks, but with its non-conformability 

 with the same, as well as with its remarkably coarse material. The line 

 of separation between the two formations is probably that separating 

 divisions 29 and 30 of our section — that is, all below that line probably 

 belongs to the Cretaceous — though we did not find any fossils in place 

 above division 23, and those found there were certainly Cretaceous types. 



When referring the coal series at Coalville to the Cretaceous, in Mr. 

 King's and Dr. Hayden's reports, I called attention to the very unusual 

 entire absence, so far as known, of the genera Ammonifcs, Scaphite.Sj 

 Baculites, and all of those various other Cejyhalopoda, as well as of many 

 other types, so generally at once distinguishing marine Cretaceous 

 rocks from those of Tertiary age. At the same time, however, I noticed 

 the presence of several species of Inoceramus, one o{ Anchura, and one 

 of Gyrodes, genera that do not occur in more modern rocks than those 

 belonging to the Cretaceous period; and it was on this evidence, and 

 the specific affinities of some of the other types, that I was led to refer 

 this series to the Cretaceous. The genus Gyprimera., Conrad, (and 

 probably several other genera yet only known in the condition of casts,) 

 may now be added to the list of Cretaceous types found in this series; 

 while the species of Gyprimcra discovered here is so nearly like G. de- 

 pressa, from the Cretaceous of North Carolina and Mississippi, as to 

 leave doubts whether it may -not really be the same. We also now 

 have the well-known Cretaceous species Inoceramns prohlematicuf^^ from 

 boih above and below the" main coal-bed at Coalville; while another 

 larger Inoceramus, from far above all the coal here, is apparently iden- 

 tical, specifically, with an Upper Missouri Cretaceous species. 



