372 DESCRIPTIVE GEOLOGY. 



crops of the Upper Coal-Measure and Weber Quartzite series betAveen 

 Parley's and Mill Creek Canons. The course of both of these canons has 

 evidently followed in general the strike of the beds, Mill Creek running 

 nearly straight through the less distorted lower beds of the Weber Quartzite, 

 while Parley's Creek Jias followed approximately the curving outline of the 

 reddish mud-rocks and shaly limestones of the Permo-Carboniferous. Above 

 the forks, however, its bed exposes the red sandstones of the Triassic, while 

 its northern wall is formed of the thick conglomerate beds, from under 

 which, here and there, appear outcrops of the Jurassic limestones. This 

 conglomerate, which is composed of large pebbles, generally several inches 

 in diameter, of quartzite and cherty limestone, in a somewhat limy matrix, 

 has some resemblance to the coarser conglomerates of the Tertiary, but its 

 matrix is so hard and compact that it fractures sharply through the hard 

 quartzite pebbles, and at the head of Parley's Canon it is found dipping 

 55° north, almost in conformity with the Jurassic and Triassic strata, while 

 its strike more nearly corresponds with the well-recognized Cretaceous beds 

 exposed in East Canon Creek. Its great thickness, and the size of its peb- 

 bles, exceeding so much that of the conglomerate, which usually marks the 

 base of the Dakota Cretaceous, may be explained by its being formed along 

 the shore of a high mountain-range, where the Cretaceous seas washed the 

 east base of the Wahsatch. 



On the divide between Parley's and East Canon Creek, the Jurassic 

 limestones are well exposed, thinly bedded, with seams of greenish clays. 

 In the hills south are the red sandstones of the Triassic; with a coarse white 

 grit at their base. The strike of these rocks is here north 35° east for a 

 short distance east of the divide, and then bends sharply to south 30° east, 

 the upper beds, or outer edge of the curve, crossing East Canon Creek into 

 the spurs of the group of hills north of Parley's Park. Parley's Park is sim- 

 ply a mountain-valley, about 6,400 feet above sea-level, consisting of some 

 meadow-land at the head of East Canon Creek, and a rolling sage-brush 

 country between that and Silver Creek. Along the ^t-hills of the high 

 ridge, which forms the main divide, to the west of the meadows, the red 

 sandstones are found striking due north and south, and sloping eastward 

 under the valley. The body of the ridge is composed of the Upper Coal- 



