OCR Text |
Show 66 RECONNAISSANCE IN THE UTE COUNTRY Crossed over to the Pacific slope; timber- line from two observations was 19,640 iuches, or 11,022 feet above the Gulf. The rocks, after leaving Camp 24, were all of Plutonic origin. In Eocky Gulch I observed a bowlder of galena two feet in diameter. Passed over gulches and through ravines strewed with fragments of feldstone, some of which had attached galena, copper, and iron pyrites in quartz gangue. Baker's Park is merely a widening of the valley of Las Animas for five or six miles, with about a half mile maximum width. Proceeding down the Las Animas Valley, the rocky walls on the right side are of feldstone, traversed by numerous veins of quartz, many of which contain minerals of different kinds. Baker's Park has a large area of good grazing- land, and its native grasses furnish forage for inauy heads of stock during the summer. The narrow valley connecting this park with Hamilton Park is too limited to be of much use. Here one branch of the corps continued the reconnaissance down the Las Animas Valley, and Laurens Hawn, assistant geologist and meteorological recorder, was detailed to take charge of these branches on this route, and the report of his researches and field- notes are herewith submitted, with my approval. F. HAWK, Geologist and Meteorologist Ute Reconnaissance. Geological notes made on the Ute reconnaissance during examination of t) ie Animas River, by Laurens Hawny assistant geologist and meteorological recorder. Ascending from the foot of Hamilton Park, at the entrrnce of the Las Animas Canon, the rocks are principally granitic until an elevation is attained on the slope of a valley of some eight hundred feet, when blue limestone appears. This, being exposed and forming a table about eleven hundred feet above the river, I traced for several miles. The formation was somewhat altered by heat. I made the following section near Camp 27, on and above the line: Nos. 1 and 2, 465 feet of sandstone. No. 3, 50 feet of gray limestone; no fossils found. No. 4, 300 feet of coarse sandstone. No. 5, 30 feet of bluish- gray fossiliferous limestone, weathers into angular fragments. Organic remains: Cimoiden; Productus equicostatus; I. reticulata; Spirifer Kentuckensis. No. 6,250 feet of greenish micaceous sandstone. No. 7, 10 feet or more of bluish- gray limestone; no fossils found. No. 8, 90 feet or more of greenish micaceous sandstone. No. 9, 200 feet slope; no outcrops. No. 10, 8 feet or more of coarse white sandstone. No. 11, 5 feet of bluish- gray limestone. No. 12, 200 feet of slope; no outcrops. No. 13, 10 feet of brown fine- grained sandstone. No. 14, 50 feet of bluish- gray fossiliferous limestone, weathering into angular fragments. |