252 GEOLOGY OF THE HIGH PLATEAUS. 



unconformable. In the cliffs of the eastern and southern margins the fol- 

 lowing series is presented : 



Feet. 



1. Gray calcareous sandstone 180 



2. White limestone ICO 



3. Eed marly limestones and calcareous shales '300 



4. Red pinkish limestone 450 



6. Conglomerate, with small pebbles and gravelly sandstone 190 



1,280 



Below these are the characteristic gray Cretaceous shales, somewhat 

 arenaceous, forming long spurs and foot-hills. They do not here form 

 cliffs, but long slopes, descending into the lower regions adjoining. From 

 the southern extremity of the Paunsdgunt they rise with a slight inclination 

 towards the south and are beveled off by erosion. At one point the sec- 

 tion crosses (southward) a decided monoclinal flexure with a maximum dip 

 of about 10° to 12° trending east and west, but quickly reflexing back to 

 a dip of 3° to 4°. One after another the formations end in cliffs and 

 ledges, and the profiles drop at each crest-line upon lower beds, until at a 

 distance of about 23 miles from the southern end of the plateau the carbon- 

 iferous forms the final platform, and rises gently but continuously to the 

 Grand Cafion. 



The western side of the plateau looks down from its northern half 

 upon the valley which carries the uj^per waters of the South Fork of the 

 Sevier River. Across this valley the gentle slopes of the Marktigunt rise 

 towards the west. Along this base of the Paunsagunt runs the Sevier fault, 

 but before reaching the end of the j^lateau its course changes from south 

 to the southwest. Just where this change occurs is the divide between the 

 valley of the Sevier and the headwaters of the Virgin, a tributary of the 

 Colorado. The wall of the plateau thenceforward becomes a cliff of ero- 

 sion gradually swinging to the southeast, then around the end of the table 

 (which projects southward like a great promontory), and finally trends to 

 the northward. The summit of the table has a central stream which 

 gathers all the drainage and cairies it northward to the Panquitch Hay- 

 field, thence into the East Fork by the way of Grass Valley, and finally 

 through East Fork Cafion into the Sevier River. 



