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Show 7 0 RECONNAISSANCE IN THE UTE COUNTRY. Hamilton Park is situated on the west side of the district, as now developed, and includes about 7, u00 acres. Mineral Creek enters the southwest corner of this park, presses along the west slope of the mountain for near two miles, and enters Las Animas Eiver. From the mouth of the creek to the entrance of the valley above, the mountain slope is mainly composed of trap. Above this the slope on the left- hand side going up is covered with surface- deposits that hide the main formations, but I believe them to be likewise trap. At the entrance to the valley on the right side going up is an escarpment several hundred feet in height, composed of cellular micaceous quartzose formation in thick beds and of a ferruginous aspect. The cells contain a fine, ashy- brown siliceous dust, and its micaceous characteristics might rank it among gneiss. Farther up the stream near the junction of the South Fork, the summit is covered with different colored siliceous matters, blending the hues of orange, purple, and crimson. The North Fork of Mineral Creek is a mere gorge. It was once filled to timber- line with recent formations, aud a sandstone and coarse ferruginous conglomerate yet occupy portions of its lower slopes, while the higher levels are of a yellow argillaceous clay and slate. These modern remnants cover most of the surface, but at a few points I observed feldstone and other trappean varieties, and in the higher peaks volcanic deposits. Fo extensive mineral \ eins had been discovered in this valley, as " prospectingv is rendered difficult in consequence of the modern deposits covering the slopes. The South Fork of Mineral Creek has a more spacious valley for three miles above its mouth. In this distance the walls on the left side going up are several hundred feet in height, and in thick beds of argillaceous quartzose and mica slate and calcareous formations. Above this, for about one mile, the wall is mainly covered by talus and surface deposits, but on the opposite ( right) side is a perpendicular wall of over 1,000 feet, and reaching up to near timber- line, and of an entirely different character. The lower beds, or those within reach, are of a dark maroon, hard, compact limestone, with beds of conglomerate of like character, and rounded pebbles. These beds alternate with thin plates of micaceous sandstone of like color, which weather out on their edges and give to the escarpment the appearance of masonry constructed after the strictest rules of architectural proportions. This exposure is seen only for about one mile, when a cascade in the stream, a dip in the formation, and denudations above the falls hide it from view on this side of the valley above the cascade, but on the opposite side ( above the falls) it occurs in a cliff of several hundred feet in height. This, too, soon disappears by the rapid ascent of the valley, and trap and volcanic deposits take its place. These red formations are, too, of a modern date, formed since the valley had assumed its present proportions, and which they once filled. Such conditions are not easily conceived from the present stand- point, especially as a branch valley was also filled, but with different material. Further comments on this subject will be made in the resum& In passing from the mouth of the valley of Mineral Creek to the left along the north boundary of Hamilton Park, the quartzose formation, previously noted, is replaced by feldstone trap, and this again by mottled granite in a small ledge at the mouth of the canon of Cement Creek. |