264 GEOLOGICAL SURVEY OF THE TERRITORIES, 



Eoaring Fork, other beds are exposed. Here Mr. Taggart made the 

 following section. The beds would be represented under the drift at the 

 point /in the illustration, (Fig. 1, Plate XIX.) The beds seem to be 

 conformable, all dipping about 40° to 50° north, 45° east: 



Section No. 29. 



In ascending order, by Mr. Taggart : 



1. Blue limestone, 20 to 30 feet. 



2. Gray compact fine-grained sandstone, 10 feet. 



3. Compact fine-grained blue limestone, 50 feet. 



4. Fine-grained sandstone, 6 to 8 feet. 



5. Space covered with debris, 150 feet. 



6. Brown sandstone, 2 feet. 



7. Brown shales, 10 feet. 



8. Fine gray compact sandstones, with small quartz pebbles, 150 feet. 



9. Dark shales, very much broken, 200 feet. 



10. Space probably filled with shales, 200 feet. 



11. Brown limestone and shales, alternating, in beds from 1 to 2 feet 



in thickness, and containing fossils; total thickness, 30 feet. 



12. Blue limestone, with interlaminated shales, 150 feet. 



This is as far as Mr. Taggart was able to carry the section. Bed Xo. 

 12 corresponds with Xo. 21 of section 28. When we cross to the east side 

 of Eoaring Fork, the beds on the hills are very much obscured. Enough 

 is seen, however, to warrant the conclusion that near the base of the 

 hills, </, are yellowish sandstones and shales. Above these are outcrops 

 of red sandstones, h, dipping north 15° east, and inclining 50°. I am 

 not satisfied as to the age of these beds, although I think it is probable 

 that they are either Carboniferous or Permo-carboniferous. The beds 

 given in Mr. Taggart's section dip conformably beneath those given in 

 section Xo. 28. They are uu doubtedly Cretaceous, as proved by the fossils 

 he obtained. Bed Xo. 20, in section Xo. 28, is probably Xo. 1 Cretaceous. 

 There would seem, therefore, to be an inversion of beds here, although 

 it is difficult to imagine what should cause it. I was unable in the short 

 time at my disposal to determine accurately the relations of these beds 

 shown in the butte to those skirting the Elk Mountain range on the 

 northeast. Crossing to the opposite side of the valley, the Cretaceous 

 beds are seen dipping to the northwest. The line of outcrop follows 

 the course of the western branch of Maroon Creek, and then turns to 

 the northwest along the edge of the eruptive area about Snow Mass 

 and the Capitol, and continues across toward Sopris Peak. The dip 

 seems to change also, being at first northwest and gradually changing 

 to the northeast. At the j)oints % and j, in the illustration. Fig. 1, Plate 

 XIX, we have two benches, with a gradual slope toward the northwest. 

 They are covered in part with a growth of aspens, and strewn over the 

 surface are numerous granite boulders of all sizes. These benches, I 

 think, must mark the old courses of Hunter's Creek, that joins Eoaring 

 Fork above the mouth of Castle Creek coming in from the east. They 

 curve toward the present bed of the stream. About two miles below 

 the butte through which the section given above was made, the river 

 cuts through the Cretaceous beds, leaving a high bluff on the west side 

 in which the beds are inclined at an angle of 15° to 20°. Opposite these 

 bluffs is a level valley filled with drift, which reaches to Cretaceous 

 bluffs on the eaet side. The river cuts its way deeply into this drift, 

 which is underlaid by Cretaceous rocks, as is shown by several expo- 

 sures along the course of the river higher up stream on the east side, just 



