FOOT-HILL SECTION. 371 



ness of these beds, viz, about 17,000 feet, which, at an angle of 55°, would 

 give a width of outcrop of nearly 4 miles, about that shown on the map. 



Emigration Canon marks approximately the line of the synclinal trough 

 between the two great folds, that enveloping the Cottonwood granite, and 

 that which curves over the Farmington Archaean body. In Red Butte 

 Canon, next north, the Triassic sandstones rise again from under the lime- 

 stones of the Jurassic, having a more regular slope to the southward, and 

 affording, in the evenness of their strata and the more compact nature of 

 some of the beds,, an excellent building-stone, which has been extensively 

 used in Salt Lake City. The Jurassic rocks as seen in Emigration Canon 

 are drab, more or less argillaceous limestones, and clayey shales, having a con- 

 choidal fracture, and breaking into little cuboidal rectangular blocks. Their 

 beds are much broken and faulted, so that no continuous section is afforded. 

 Their strike is, in general, nearly east and west, not, therefore, parallel with 

 the direction of the canon. About 5 miles from the mouth of the canon, 

 the Triassic sandstones are again exposed, and here the synclinal structure 

 and basining-up of the Jurassic strata are more distinctly seen ; but a short 

 distance above this point, both formations are concealed by beds of a very 

 coarse conglomerate, which, on stratigraphical and lithological grounds, has 

 been considered to represent the lower bed of the Cretaceous. The Jurassic 

 beds are exposed again, under the conglomerate, in a ravine near the head 

 of the north fork of Parley's Creek. 



The low divide where the road crosses from Emigration to Parley's 

 Canon, is in the line of the Jurassic synclinal, shown in the foot-hill section. 

 The outcrops in general are much obscured by the unconformable conglom- 

 erate; but, on the north side of the divide, the red sandstone can be seen 

 dipping 45° to 50° south, with some beds of light sandstones and limestones 

 over them, while, on the south side of the divide, the same series can be 

 recognized dipping northward, with a northeast strike, overlain by the light- 

 colored limestones of the Jurassic. In Parley's Canon, the inud-rocks and 

 limestones of the Permo-Carboniferous underlie the Triassic sandstones con- 

 formably, but show great irregularities in strike and dip. The Triassic anti- 

 clinal of the foot-hill section can no longer be recognized; but the influence 

 of the same folding which produced it is seen in the widening of the out- 



