GEOLOGICAL SURVEY OF THE TERRITORIES. 159 



and covered with drift, and then with grass, that the underlying rocks 

 are not to be seen. The industry shown by the Mormons in this valley 

 is worthy of all praise. The litfre streams are made use of to irrigate 

 the rich bottom lands, which produce abundantly, and the houses look 

 neat and comfortable. Fruit cannot be raised to any extent in the 

 Weber Valley. The varieties of trees are confined mostly to the bitter 

 Cottonwood, although from Echo City down we meet with a small dwarf 

 oak, box-elder, striped maple, and choke-cherry. 



Just below the little village of Enterprise I saw in the hills, rocks 

 composed of an aggregate of quartz pebbles. Still farther down we 

 come to feldspathic rocks, indicating that the dip of the gneissic beds 

 of the Wasatch range is westward. The Wasatch range is composed of 

 gneiss, so far as the rocks can be seen along the Weber. The rocks are 

 beautifully banded everywhere. There are also coarse aggregations of 

 quartz and feldspar, with large masses of tourmaline ; and all through 

 the gneiss, are seams of feldspar and quartz of various thicknesses. 



The evidence is quite clear that from Morgan City to the entrance of 

 the Wasatch Canon stretched a lake, the waters of which must have 

 filled up the valley, rounded off the hills, and covered the sides of the 

 mountains with loose debris. Along the sides of the canon of the 

 Wasatch, four and a half miles long, are thick deposits of loose sand, 

 interspersed with water-worn boulders in many places. These deposits 

 have been cut through in making excavations by the railroad, and the 

 lines of current deposition are curiously well marked. About half way 

 through the canon there is a sudden bend in the Weber River, by which 

 a small portion of one of the gneissic ridges is cut off. Opposite this 

 ox-bow, a canon descends the mountain side, down which a vast quantity 

 of loose material has been swept, filling the channel of the river with 

 local drift, and probably driving the current through the gneissic ridges. 

 The Weber River, if its channel were straightened, would run through 

 this deposit of drift, which is about thirty feet thick ; instead of which 

 it makes a bend and cuts its way through a massive gneissic ridge. 



Extensive deposits of whitish, fine-blue and rusty -yellow sandstones, 

 hard enough for building purposes, with flesh-colored marls, probably of 

 pliocene age, and resembling very closely in many respects the more 

 recent tertiary beds along the Platte, occur in this valley. These recent 

 beds dip east or southeast. We thus learn that some of the later move- 

 ments in the elevation of these mountain ranges have been of compara- 

 tively modern date. Terraces continue to show themselves the entire 

 length of the Weber River, and they are probably synchronous with 

 those which surround the basin of Salt Lake Valley. 



After emerging from the Wasatch Caiion of the Weber valley, we 

 pursued a southerly course along the base of the Wasatch range to Salt 

 Lake City. For twenty miles or more all the unchanged rocks have 

 been worn away from the flanks of the mountains, or completely con- 

 cealed by debris. All over the gentle slopes at the foot of the moun- 

 tains are strewn masses of rocks, all gneissic and evidently derived 

 from the central parts of the mountains. Terraces surround this basin 

 everywhere. There is one large one, with two or three smaller ones, 

 on the sides of the mountains ; and from the lowest one downwards the 

 surface slopes gently to the lake. I was informed that the lake had 

 risen nine feet vertically since 1868, and of course the" water has ag- 

 gressed upon the land to a great distance. I have heard no explanation 

 of this phenomenon. All the lakes in the West are said to be rising 

 more or less. 



The carboniferous limestones begin to make their appearance along 



