GEOLOGICAL REPORT. 327 



the Permian (see under stratified rocks). The sedimentary rocks continue all the way 

 down Timpanogos Canon. At its upper end compact siliceous and calcareous sand- 

 stones prevail, which may also belong to the Permian formation; while lower down 

 we find more dark-gray, impure, siliceous and slaty limestones, frequently threaded 

 with numerous veins of calcareous spar or dolomite, some of which exhibit many fos- 

 sil remains, expecially Bracliiopoda ; also dark bluish-gray argillaceous, siliceous, and 

 calcareous slates. In the lower part' of the canon, and at various points south of its 

 entrance, bluish-black argillaceous shales are exposed, containing a great deal of car- 

 bonaceous matter, and, on their decomposed surface, crystals of gypsum and efflores- 

 cences of sulphate of magnesia. At the mouth of the canon, again siliceous and cal- 

 careous slates predominate. 



Of all these rocks I have spoken before, and stated that they all, or partly, repre- 

 sent the upper division of the Carboniferous formation. They present no uniform dip, 

 but are much disturbed and contorted: here horizontal, then bent with a sharp angle, 

 or forming vaults, or folded up so that the continuity of the overlvhig strata is alto- 

 gether broken, then rising at once vertically from the bottom of the valley many hun- 

 dred feet, they again appear horizontal higher up, and thus continue in a <'ii>antic 

 wedge-shaped mountain to a great altitude, as if they had never been subject to any 

 violent actions from underneath — in reality, however, because only the horizontal por- 

 tion of the strata could withstand destruction, while their bent and crushed continua- 

 tions did not retain strength enough, and were eventually precipitated down and de- 

 stroyed. 



The canon forms a chasm in these disrupted strata, not less than 1,500 feet deep! 

 and presenting a picturesque scenery, while the highest summits reach to the region 

 of nearly perpetual snow, over 4,000 feet above the mouth of the canon. This whole 

 thickness seems to be made up of similar strata: at least the red color which character- 

 izes many of the more modern strata, on the eastern side of the range, was not ob- 

 served on these peaks. 



The Upper Carboniferous formation is developed also at other points in the west- 

 ern portion of the Wahsatch Mountains. Prof. I. Hall recognized it in some fossils of 

 Captain Stansbury's collection, from the vicinity of the Great Salt Lake. 



Near the mouth of Dry Creek Canon, east of the northern end of Utah Lake, a 

 white granitic rock forms a high mount, but I did not notice near our routes any meta- 

 morphie schist- which Captain Stansbury also observed near Salt Lake. In the hills 

 north of Cedar Valley I noticed a small knob of a similar granite, scarcely reaching 

 the surface, the stratified rocks near which exhibit strong marks of metamorphism. 



The general character of the valley of Utah Lake and Jordan River is in all re- 

 spects like that of the other valleys of the basin, as described above. The mountain 

 range between Utah Lake and Cedar Valley consists of similar strata, apparently of 

 Carboniferous age. 



In the hills a few miles west of Camp Floyd, I noticed siliceous limestones, sand- 

 stones, and siliceous slates, also shales. By their fossils they are characterized as 

 Lower Carboniferous. (See above under Stratified R. >cks. ) Similar r< >eks occurnearOld 

 Camp Floyd, at the north end of Cedar Valley. The stratification seems to indicate 



