158 GEOLOGICAL SURVEY OF THE TERRITORIES. 



mile in length and forming a huge chasm or gorge, which is called here 

 the Narrows. After passing through this ridge the Weber receives 

 Lost Creek, and makes an abrupt bend to the southward ; and here is 

 exposed an immense thickness of the older rocks, in a nearly vertical 

 position. These rocks extend down the Weber River four miles or 

 more, when the beds abruptly change from the nearly vertical position 

 to a nearly horizontal one. 



Commencing near the Narrows, at the mouth of Lost Creek, we have 

 a considerable thickness of the Jurassic limestones and marls, dipping 

 70° or 80° northeast, of a bluish ash color, very hard and brittle, cleav- 

 ing into thin layers and fracturing in every direction, so that the sides 

 of the hills are covered to a great depth with its debris. Then comes 

 a series of mud shales, with ripple marks, some layers of very white 

 sandstone, and a thick bed of hard red sandstone, destined to take the 

 highest rank among the building stones of Utah. It can be easily 

 wrought into fine forms for culverts, fronts for buildings, caps and sills, 

 &c. Then comes a vast thickness of gray and dark-gray, more or less 

 cherty limestones, which are probably carboniferous ; and below these 

 again a very hard siliceous rock, oftentimes massive, portions of which 

 are filled with holes at right angles to the layers, very similar to much 

 of the Potsdam east of the Mississippi, pierced by Scolithus linearis. In 

 this quartzose group there is a bed of shaly limestone, six to ten feet 

 thick. A few indistinct moliusks were observed in the limestones and 

 the mud shales. 



The distance from the mouth of Lost Creek to the end of the nearly 

 vertical series of rocks is about three miles. So that we have here a 

 thickness of strata not much less than two miles in thickness from the 

 top of the Jurassic downwards, so as to include the carboniferous. 



At the mouth of Lost Creek there is a remarkable example of non- 

 conformity in hills of different ages. The reddish conglomerate rests 

 directly upon the upturned edges of the vertical beds described above, 

 and it is an important question what has become of all the intermediate 

 beds, containing the coal, which are so conspicuous about five miles 

 above Echo City. 



Descending the Weber from the Narrows, we find some of the most 

 remarkably rugged scenery in the West. The walls are very noticeable, 

 and are formed of two beds of limestone, projecting from the sides of 

 the valley at right angles, from between which ten or twelve feet of loose 

 material has been washed out. Near the tunnels the rocks on the left 

 side of the Weber dip about 10° nearly north, while on the other side 

 the strata incline in the opposite direction 3° to 5°, as if the valley was 

 anticlinal. Then again the valley would appear to be monoclinal, the 

 strata on the right side of the river inclining 20° south, and on the 

 opposite side, though presenting a nearly vertical front, inclining south 

 also. A little farther on down the valley, and on the right side of the 

 river, come beds of red sandstone ; below these again gray sandstone, 

 with a reddish tinge, the red sandstone dipping east 12° ; while on the 

 opposite side of the river the hills are open, rounded, and grass-covered. 



The cherty crinoidal limestone extends to Morgan City and gradually 

 disappears. The red sandstones are seen among the foot-hills. 



At Morgan City we come out of the principal caiion of the Weber into 

 a broad open bottom, filled with little villages and farm-houses. The 

 soil is of great fertility. The hills on either side are smoothed off and 

 covered thickly with loose material and vegetation. The high vertical 

 exposures all disappear. The Wasatch range seems to trend nearly 

 north and south; even the foot-hills of this range are so smoothed off 



