GEOLOGICAL SURVEY OF THE TERRITOEIES. 



193 



liiffher 



':ribiiced tlieir sediment, when tbe lake-waters were at tliese ^,^. 

 levels. Thirteen of these terraces were observed ou a liue between the 

 center of the town and the mouth of Ogden Canon, the highest of which 

 was less than 400 feet above the railroad. Above this point, the foot of 

 the mountain has been swept so bare of rubbish as to show no terrace 

 until we reach the highest, which was slightly outlined on the uj)per 

 slopes. 



Most of the material of these terraces is entirely uncompacted, and 

 the edges expose beds of drifting sand and loose gravel ; but, at two or 

 three levels, there are layers, a few feet in thickness, in which a cal- 

 careous cement has more or less consolidated the gravel into still rather 

 loose and porous conglomerates. 



The debris thus deposited along the base of the mountain has so cov- 

 ered the solid strata as to make it 

 difficult to determine their exact 

 positions at this low level ; but the 

 upper slopes show so much bare 

 rock as to make the general struc- 

 ture very evident. The beds form, 

 as was stated in last year's report, 

 a huge anticlinal, whose axis makes 

 a small angle with the general trend 

 of the range; but it proves to be 

 much more complicated than was 

 then supposed. While its eastern 

 slope is nearly regular, its western 

 is quite irregular, including at least 

 two subordinate folds, large por- 

 tions of which have been eroded, 

 so that one must study closely, to 

 be able to supply the missing links. 

 The accomi)ai]ying sketch (Fig. 

 44) shows, in a general way, tiie ac- 

 tual and theoretical section through 

 the range, at Ogden Peak. 



In the more northern portion of 

 this block of mountain, both of the 

 folds of the western slope make 

 considerable outcrops; but their 

 axes are so much inclined to the 

 horizon that the bottoms of the 

 folds rise rapidly as we go south- 

 ward, until they pass above the 

 present smfoce, leaving the west- 

 ern slo])e here entirely composed of 

 metaraorphic rocks, in which no 

 continuation of these particular 

 folds can be traced. The southern 

 portion of the eastern slope was not 

 examined; so that I cannot say 

 Just at what point of the eastern 

 base the unmetamorphosed rocks disappear from it; but they certainly 

 show no outcrop in the section displaved along Weber Canon. At two 

 or three points, the metamorphic rocks show some sliglit easterly dips; 

 but most ot their dips are strong westerlv, and the overlying beds are 

 plainly uneonprmahle. The metamorphics are mostly hornbleudic 

 13 G s 



