OCR Text |
Show 68 RECONNAISSANCE IN THE UTE COUNTRY. No. 14, 20 feet of limestone, varying from white to blue, and breaking into angular fragments. No. 15, 25 feet calcareous sandstone. No. 16, 3 feet or more of fossiliferous cherty limestone. In this formation recur the sub- carboniferous fossils: Crinoidea, Pro-ductus reticulatus, Gorgonia, Euomphalua laius, and Cyathophylum. The strata of this section dip west to an angle of about 10°. From this point to Camp 30, in several places, cherty limestone appears, but its position in the section or its volume is not determined. In consequence of the press of time and other duties, the thickness of the different formations may not be correctly estimated, but enough is determined, together with the organic remains obtained, to prove that here at least are extensive beds of carboniferous rocks. The walls of Cascade Creek, at Camp 30, are composed of gray and cherty limestone. This formation probably belongs beneath the section last recorded, since that series lay in the cliffs a short distance to the rightof the point. ( See No. 16 of last section.) In this limestone were found the following organic remains: Crinoidea, Productus reticulata, Gorgonia, Euomphalvs latus, and Cyathophylum. This formation may, with propriety, be referred to the sub- carboniferous, as I believe the Euomphalus latus is never found above that division. So far it is definitely classified. Other formations came in below, and, though not defined, are believed to belong to the same division. On higher ground I traced these formations in their relative position to Camp 31. Between Camps 30 and 31 the route lies over a high plateau, exceedingly fertile and well watered by numerous springs, which in places form marshes. The grass and other herbage is rich and abundant. The same formations continued in the bluffs between Camps 31 and 32. The sandstone becomes more compact and less micaceous, and frequently changes to a reddish- brown, caused by heat. Descending from the high plateau to Animas Park, the strata dip south at an angle of 15°. Numerous thermal springs flow from the limestone formations near Camp 32, in which I recognized sulphur and iron and other minerals not determined. These springs are small, the largest discharging not more than five or six gallons per hour. Some of these waters are pleasant to the taste and in their effect. After leaving the high plateau the soil becomes dry and sandy, except when watered by an occasional spring, and shrub- oak becomes abundant. Below Camp 32 the dip carried the series beyond recognition. About three miles below Camp 32, on the summit of the cliffs to the right and parallel to the river, appears a dark and micaceous sandstone, fine and compact, characteristics differing from those in the series before described. The volume of this red sandstone increases in thickness as it dips south, by the accumulation of strata on the top, until it equals about 1,000 feet in thickness, after which it is soon carried below the surface of the park, by the dip caused by subsidence or an extensive slide prior to the present order of things. The distance from where it first appeared to where it disappeared is about five miles. This formation is also in the cliffs on the opposite side of the river. For the want of time, and owing to the rapidity of the changes of the cliffs in which the red sandstone first appears, I was unable to determine the characteristics of these cliffs, but believe the upper and higher portions of the slope of the valley likewise sandstone of a different nature. The red sandstone slide to which I have referred |