210 GEOLOGICAL SURVEY OF THE TERRITOEIES. 



tMcker. Thus, instead of 60 to 80 feet of the Potsdam, in Glen Eyrie, 

 we have only 40 feet. The beds correspond, beds 2 to 5 of section No. 

 4 being the same as 2 to 5 of jSTo. 7. So it is with the limestones above. 

 At Glen Eyrie we have 73 feet where there are over a hundred on Trout 

 Creek. Bed 14, of section No. 3, is, I think, the same as the white 

 limestone above the pink shaly limestones on Trout Greek. Eeturning 

 again to the head of Trout Creek we cross into Haydeu Park. This 

 name has been given to the low rolling country to the west of Pike's 

 Peak. Hayden Park is drained by Trout Creek, West Creek, and 

 Beaver Creek. The latter flows to the northwest, and empties into the 

 South Platte just below the upper caiion. About five miles from its 

 mouth, around the settlement of Florissant, is an irregular basin filled 

 with modern lakQ deposits. The entire basin is not more than five 

 miles in diameter. The deposits extend up the branches of the creek, 

 which all unite near Florissant. Between the branches are granite 

 islands appearing above the beds, which themselves rest on the granite. 

 Just below Florissant, on the north side of the road, are bluffs not over . 

 50 feet in height, in which are good exposures of the various beds. 

 The following section gives them from the top downward : 



1. Coarse conglomeritic sandstone. 



2. Fine-grained, soft, yellowish-white sandstone, with bands that are 



more or less argillaceous, and containing fragments and stems of 

 leaves. 



3. Coarse gray and yellow sandstone. 



4. Chocolate-colored clay shales with fossil leaves. At the upper i)arfc 



these shales are black and below pass into 



5. Whitish clay shales. 



These last form the base of the hill. Tile beds are all horizon- 

 tal. Scattered around are fragments of a trachyte which probably 

 caps the beds. In one of the valleys,' Mr. Taggart discovered, near an 

 old well, pieces of trachyte, which, on looking at the excavation, was 

 found to be the first layer penetrated. The point of overflow from which 

 this material came is probably to the southward, in Dr. Endlich's dis- 

 trict. The lake basin may possibly be one of a chain of lakes that ex- 

 tended southward. I had thought it possible that the beds were of 

 Pliocene age. The specimens obtained from bed No. 4, of the section 

 above, were submitted to Professor Lesquereux, who informs me that 

 they are '' Upper Tertiary." "But I do not believe, as yet, that the 

 specimens of the Green Eiver group to which your species are referable, 

 authorize the conclusion of Pliocene age. I rather consider it, as yet, as 

 Upper Miocene. The species known of our Upper Tertiary are as yet 

 too few and represented in poor specimens for definitive conclusion. 

 Tour specimens have a Myrica, a Cassia, fragments of Salix augusta, 

 (A. Br.,) a Rhus, an JJlmus, and a fragment of a Poa or Poacites.''^ 



The shales were so soft and friable that it was rather difficult to ob- 

 tain any specimens. 



About one mile south of Florissant, at the base of a small hill of sand- 

 stone, capped with conglomerate, are 20 or 30 stumps of siJicified wood. 

 This locality has been called " Petrified Stumps -' by the people in the 

 vicinity. The specimens of wood are not particularly good. 



The upper caiion of the South Platte Eiver is about eight miles in 

 length, and marks the exit of the river from South Park. The range 

 in which it is, if it deserve that name, is the eastern boundary of the 

 park. The rock is all granitic to the northward and to the northeast. 

 South of the canon is an area of volcanic overflow which extends south- 

 ward into Dr. Endlich's district, and I will only refer to it again in 



