peale.] DESCRIPTIVE GEOLOGY CACHE VALLEY. 605 



of greenish sandstone, with white and light brown limestones and 

 shales ; in the latter shells of the following genera were found : 



Limncea ? 



Valvata ? 



Planorbis ? 



Splicerium f 



They are apparently identical with existing species. Ou the north 

 side of the Bear a gray sandstone outcrops, which is probably above the 

 fossiliferous layers. In the caiion as far as could be seen limestones 

 outcrop. We had very stormy weather while here, and had to leave a 

 number of points unvisited. On our south line a little west of south 

 from the Gates, the Wahsatch Eange ends in a high peak, around the 

 northern foot of which the Pliocene beds extend from Cache Valley to 

 Malade Valley. • 



The following notes on the region of the Gates is taken from Profes- 

 sor Bradley's Beport for 1872, p. 199 : 



The immediate channel of Bear River, where it "breaks through the mountain, at 

 the point known as "The Gates," is narrow, with high precipitous walls of light drab, 

 compact limestone, partly siliceous, from which I could obtain no fossils; but from its 

 position it must be Carboniferous. The strata show a westerly dip of about 25°, and 

 evidently belong to the west side of the anticlinal upheaval, whose southern con- 

 tinuation has been mentioned as crossing Box Elder and Ogden Canons. The cliffs of 

 this narrow channel reach nearly to the level of the top of the second principal ter- 

 race. On the north side of "The Gates," a short distance back from the edge of this 

 channel, there is another considerable break in the upper terrace, showing a second 

 channel to have existed when the stream was at this level ; and as seen from this 

 north side, the appearance of the surface on the south side indicated the probable ex- 

 istence of still a third old channel, along the line now occupied by the Utah North- 

 ern Railroad (narrow gauge), which there crosses the range into Cache Valley. At 

 the level of the upper terrace the old valley of Bear River spreads out to a width of 

 about five miles. The upper terrace itself consists almost entirely of a grayish- white 

 limestone, partly fine-grained and compact, partly coarse and porous, and mostly 

 pebbly. All of it is more or less oolitic. The compact layers are entirely destitute of 

 fossils; but the more pebbly portions contain very numerous individuals of a few 

 species of fresh-water shells, which are sufficient to mark the bed as of late Tertiary 

 (Pliocene ?) age. * * * The beds exposed are about 200 feet thick. They show at 

 this point a dip of about 25° south 68° west. As no corresponding disturbance of the 

 surface of the terrace is apparent, it is evident that the upheaval antedates the Ter- 

 race epoch. The lower terraces show extensive deposits of coarse gravel, which are 

 well exposed in the cuts of the Utah Northern Railroad, and supply that road with 

 an abundance of superior ballast. 



There are knobs of limestone both north and south of the canon, and 

 at a point about four miles south they outcrop at the base of a bluff.* 



East of the south end of the Malade Eange, the sandstones and shaly 

 limestones of the Pliocene again outcrop, dipping to the eastward 5° to 

 10°, as at the Bear. Here also I obtained the following : 



Planorbis 1 



Sphcerium % 



Bythinella f 



East of this locality is a high butte of the same beds. At the eastern 

 base limestones probably outcrop, but of what age I do not know. North 



'According to the Report of the United States Geological Exploration of the 

 40th Parallel, Vol. II, Description, there is volcanic outcropping in the canon. The 

 following is the note : "An appearance of volcanic rock in the canon of Bear River, at 

 the ' Gates,' which, however, was not examined closely enough to determine definitely 

 its character, suggests the possibility that this uplift may have been determined by a 

 late volcanic outburst." This volcanic rock Professor Bradley does not appear to have 

 seen, nor did I. 



