108 SUEVEY OF COLOKADO AND NEW MEXICO. 



or triassic beds. South Park, &c. Also, accompanying tlie coal in thin 

 scales. 



Anhydrite. — Elk Creek. 



Salt, (XaCl.) — In solution in many springs. As dei^osit on rocks in 

 their vicinity. 



Heavy s])ar^ (BaO . SO3.) — As gangue rock in many mines. Baker 

 lode, «&c. 



Meteoric iron. — Found near Bear Creek. 



Beryl, (Al203.2Si03 + GI2O3 2 SiOg.)— Bear Creek. 



Bfvcite, (MgO . HO.)— Jauies Creek. 



Idocrase, [(CaO + MgO) SiOg]— Bear Creek. 



[LAPOETE ON THE CACHE A LA POUDEE. 



The town lies on both banks of the above creek. The appearance of 

 the country is that of a number of superposed layers or strata dipping 

 from the mountains, and presenting a steep and more or less rugged 

 basset face toward them. The caiion along which the river makes its way 

 through these "hog-backs" intersects the latter nearly at right angles. 

 We followed a canon to the north of that of the river, and rode twelve 

 miles to the extremity of the bluff on the left. The bluff to the right 

 hand was broken, and exhibited a clearly defined stratified side with 

 red sandstone, limestone, and conglomerate succeeding each other in 

 the order named. 



On turning the extremity of the bluff to the right we came upon a 

 very weathered syenite region remarkable for the redness of its talus. 



The mineral veins which our guide brought us to see were all situated 

 within an area of a square mile or so, in these syenite hills. 



The first i)roved to be a dike or vein of syenite intersecting an older 

 rock of the same, which showed on the surface a very thoroughly decom- 

 posed rock, containing an excess of iron, Avhichgave it a specific gravity 

 rather higher than usual and a dark brown color. Hornblende pre- 

 dominated in the rock. There were here and there traces of various 

 ores of copper, and lining the walls of the small cavities in the rock 

 was observed a thin film of gypsum and chloride of sodium. This spot 

 was situated upon the east bank of the North Fork of the Cache a la 

 Poudre, and about three hundred feet above that stream. 



The next opening we visited was about half a mile northwest, and 

 was called Maxwell's opening. This was again a dark-colored, not very 

 distinguishable syenite, coated with malachite, and more or less per- 

 meated by copper pyrites. The opening was seven feet deep and the 

 crevice four or five feet wide, and the two pay streaks situated, the one 

 against the south wall rock, and the other about thirty inches there- 

 from. The ore becomes harder and more solid the deeper it is found. 



Hole No. 3 was three hundred yards from No. 2. It was about four 

 feet deep, two and a half inches wide, and four feet long. The rock was 

 silicious and intimately mixed with a yellowish clay, which, with the 

 reddish tinge due to the oxide of iron, gave the whole mass a copper 

 color, which probably misled the prospectors and caused the digging of 

 the hole. A little copper pyrites was observable and a verj^ little ma- 

 lachite. 



Hole No. 4 had been sunk by some Frenchmen fifteen feet deep, three 

 and a half feet wide, and five feet long. The rock described as compos- 

 ing No. 3 occurs with a curious slag-like silex containing very i)lain 

 pseudomorphs of cubes of iron pyrites. In this ore was a little copper 

 pyrites and malachite. 



