120 GEOLOGICAL SUEVEY 01 THE TEEEITOEIES. 



The sections in Plate III show the gypsiferous series below the Bed 

 Beds at the points marked a. They are probably the same beds I noticed 

 last year* on Frying-Pan Creek, above shales and sandstones that I 

 then referred to Carboniferous. I did not know exactly where to put the 

 gypsiferous beds, whether to include them with the Bed Beds which were 

 exposed in the hills above or to place them with the Carboniferous. 



In the lower caliou of the Eagle, which extends to the mouth, the 

 gypsiferous beds are well exposed, dipping from the river on both sides, 

 leaving the channel in the axis of the anticlinal. Near the mouth of 

 the river a flow of lava' from the hills on the eastern side has forced the 

 river to the opposite side, and it has scooped out a large portion of 

 these soft beds. The Bed Beds here cap the bluffs on either side. 



Grand River. — The gypsiferous beds continue from Eagle River to the 

 Grand, and follow it to within a short distance of the canon, when the 

 line crosses to the southwest and appears again on a creek, at first only 

 capping the bluffs on the east side, but gradually showing in the bed of 

 the creek as we ascend. They do not appear again until we cross to 

 Boaring Fork, where they show beneath the Bed Beds of the hog-backs 

 that extend along the western side of the creek, below Bock Creek. 

 They are represented at d in Fig. 2, Plate IV. At first the series is seen 

 only on the western side of Boaring Fork, but as we go down they grad- 

 ually appear on the eastern side, also extending up a small branch that 

 comes in from the east. On the western side, at first they have a ter- 

 race-like surface. Further down they form bluffs, on the sides of which 

 they weather into pinnacles and spires of yellow and pink colors. They 

 continue to the Grand, where the Bed Beds appear above them on the 

 south side, and on both sides of Boaring Fork. Below the mouth of 

 Boaring Fork the gypsiferous beds cross the river into Mr. Marvine's dis- 

 trict. In Fig. 1, Piate IV, they are shown at the point e to/ in the sec- 

 tion on the north side of the Grand. 



Gunnison River. — The gypsiferous series does not show anywhere on 

 the course of the Gunnison or its tributaries in our district. 



* Eeport of United States Survey for 1873, page 266. 



