PEALE.] 



GEOLOGY SECTION NO. 2. 



197 



merely indications of the red bands, the prevailing color of the sandstone 

 being a creamy yellow. The lower beds are perhaps deeper in color and 

 not so much mottled as at the point where section No. 1 was made. I was 

 unable to carry the section any farther to the eastward. Willow Creek 

 after leaving the hog-backs turns and flows nearly northward, emptying 

 into the South Platte Eiver five miles below the canon. As we go 

 south from Willow Creek, the upturned edges of the sedimentary beds 

 are covered up, and. between Jackson and Spring Creeks we find resting 

 on them sandstones of Tertiary age, which reach to the edge of the 

 hills. These sandstones contain fossil leaves in which Professor Les- 

 quereux has recognized Flaianus noMlis and a Sahal. The beds are prob- 

 ably lignitic. On Jackson Creek are some well-defined terraces sloping 

 from the mountains. Qn Spring Creek the sedimentary ridges again 

 show themselves, and on Bear Creek we have them beautifully exposed 

 in Pleasant Park. This beautiful little park is studded with pines. Its 

 western boundary is the range of foot-hills, while on the east the main 

 hog-back (Cretaceous No. 1) separates it from the valley of West Plum 

 Creek. Bear Creek flows through the jDark, cutting across the ridges at 

 right angles to the strike. Inside the sandstone wall we have ridges of 

 sandstone and limestone, giving the pp'k some most picturesque 

 scenery. Just before reaching the park. Bear Creek flows in a series of 

 cascades through a deep and narrow caiion in the foot-hills. Plate II 

 shows the outline of a section through Pleasant Park eastward across 

 West Plum Creek Valley to one of the mesas between the two branches 

 of Plum Creek. The following is the section : 



Seation No. 2, iliroiigh Pleasant Parle. 



In 



o 



2 



3 

 •-5 



ascend 

 a.~ 1. 



c ^ 



< ^-i 



c.i 0. 



d 



(11. 

 e.— 12. 

 C13. 

 14. 

 15. 

 IG. 

 17. 

 18. 



ing order: 



Granite. 



Very coarse white sandstone, 80 feet. 



Eed calcareous sandstone, 4 feet. 



Dark purplish cherty limestone, 3 feet. 



Compact red sandstone in layers of one foot thickness, with 

 cross seams of calcite, 15 feet. 



Eed calcareous sandstone, very hard, and with cross cleav- 

 age layers of one inch, 3 feet. 



Irregular limestone, with pebbles of greenish chert and lime- 

 stone, 3 feet. 



Indistinct outcrop of limestone with chert pebbles and fos- 

 siliferous : in the upper part of the space we have a 

 purplish sandstone, above which is a gray sandstone 

 passing into the next bed, G feet. 



Coarse white sandstone loosely aggregated. In the upper 

 part of these beds there are bands of red sandstone vary- 

 ing in thickness from one to three feet, 80 feet. 



/■< 



Space covered up . 



Massive red sandstones 



Mottled yellow and red sandstones. 



Space 



Pink arenaceous limestone, 4 feet. . 



Space 



White limestone, 3 feet 



Space, 48 feet 



Fine sandy limestone shales, 4 feet. 



About 1,500 

 thickness. 



feet in 



