18 GEOLOGICAL SURVEY OF THE TERRITORIES. 



are two well-dcrined lines at least, and the river terraces, which are con- 

 fined to the streams and do not seem to have any direct connection with 

 the former. These river terraces are so marked a featnre in the landscape 

 that they woidd not be overlooked by the traveler. The lowest plain 

 valley opposite the canon, near the water's edge, was fonnd to be 4,344.8 

 I'eet above the sea-level. First terrace, 4,G83.8 feet: second terrace, 4,770.5; 

 third terrace, 4,858.0. These terraces will show more clearly than any other 

 evidence we have, the gradual decrease, step by step, of the waters of the 

 ancient lake, and the operations of the little streams pouring into it from 

 the mountains on either side. The amount of local drift that has been 

 swept down through the gorges or ciiions and lodged at the opening is 

 very great. At the immediate mouth of the canon the bowlders are quite 

 large, varying in diameter from a few inches to sevei al feet. As we travel 

 westward toward the shore of the lake the bowlders diminish in size and 

 cpiantity, and the finer sediments, as sands and marls, increase, showing 

 a constant decrease in the power of the currents of the water after leav- 

 ing the mouth of the caiion. Ascending the Box Elder Caiion we find 

 the sides almost vertical, rising to a height of 1,500 to 2,000 feet. The 

 rocks are gneiss, quartzites, slates; these quartzites again inclining 30^ 

 to 70°. After passing up the narrow gorge for about two miles in a 

 straight line, with just room for the little stream, with the road 

 with the lofty precipitous rugged walls on either side, we come 

 out into an open i)ark-like area, about three miles in extent from east 

 to west and four miles from north to south, which forms a level plain 

 about 900 feet above Salt Lake. On the east side of the park there is 

 a great thickness of alternate layers of slaty shale and rusty-yellow quartz- 

 ites, varying in thickness from one-fourth of an inch to twenty inches, 

 inclining northeast at an angle of 45^, and one is an immense thickness 

 of steel-blue limestone, which x^rojects up near the summit of the hills, 

 in sharp, craggy pinnacles. In these limestones is an abundance of 

 Syringopora, Foiestella, Spirifer, Prodiictios, sufficient to show that they 

 are of Carboniferous age. Upon the surface of the layers of quartz- 

 ites beneath are impressions of what ai)pear to be sea- weeds in 

 the greatest abundance, so that large masses of the rock, which is in 

 many instances a sandstone, with a reddish tinge, look like the Medina 

 sandstone of Kew York, covered with the AriJirorophycus Rarlcmi. 



In the park the river terraces are well defined, really constituting the 

 arable land in the mountains. 



The little Danish Mormon village of Copenhagen is located on a terrace 

 in this park. The farms of the settlers are in common, and are cultivated 

 by irrigation with success. To show how much available land there is, we 

 estimated it at twelve square miles, or over 7,000 acres. The park is 

 surrounded by high mountains, which protect it from great extremes 

 of temperature, and the elevation above the sea is 4,958 feet. The 

 mountainous jportions of Ii^orthern Utah are full of these beautiful park- 

 like areas, which are most probably the remains of an ancient lake. The 

 wells which have been dug by the settlers show a considerable amount 

 of drift or bowlder deposit, with fine w^hite or yellow marly sands and 

 clays in regular layers, showing the deposit to be Post-Pliocene, and 

 that the waters of the lake were comparatively quiet. The interesting 

 features of this park are the large springs at the base of the high hills 

 which surround it. On the south side there is a spring of very pure 

 cold water, flowing out from beneath limestone mountains, forming a 

 stream of 10 feet wide and 1 foot deep, supplying water for irrigating a 

 large part of the park. On the north side there is a spring about the 

 same size as the others. Other springs occur often, so that this little 

 park is intersected with small streams in every direction. 



