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Show Table 1.- Generalized stratigraphic summary of the consolidated rocks of the Heber- Kamas- Park City area- continued Age Formation Lithology and thickness Water- bearing properties . vanian Weber Quartzite Chiefly gray crossbedded sandstone. Thickness up to 3,000 feet. Yields small amounts of water to a few wells. Primary permeability is very low, but reportedly yields large quantities of water from fractures in the mine workings near Park City. Principal source of water in the mines. I Morgan Formation Red sandstone and shale interfingers with the Weber Quartzite in part. Thickness up to 1,000 feet. No information on water- bearing properties in the study area, but primary permeability is probably low. Round Valley Limestone Light- gray marine limestone. Thickness 250- 400 feet. No wells penetrate the formation in the study area, but it yields water to numerous springs. Pennsylvanian and Mississippian Manning Canyon Shale Marine shale, siltstone, claystone, and limestone. Thickness 300- 500 feet. Not penetrated by wells in the area, but supplies a few small springs. Mlssissippian and Devonian Mississippian and Devonian rocks undivided Chiefly marine limestones and dolomites. Thickness from 3,000 to 6,000 feet. Not penetrated by wells in the area, but yields water from fractures and solution openings to many springs. A major aquifer. Cambrian Cambrian sedimentary rocks undivided Chiefly shales and quartzites. Thickness uncertain, probably up to 3,000 feet. Not known to yield water in the study area. Precambrian Precambrian rocks undivided Chiefly metasediments. Thickness unknown. Water- bearing potential unknown, but probably small. Recharge In most of the mountainous area, the soil cover is thin and permeable, and rain or snowmelt can infiltrate readily. The rapidity of infiltration into the rocks in the mountains is indicated by the reports that the discharge of the mine tunnels in the Park City area increases noticably during the period of spring snowmelt and runoff. Moreover, observation well ( D- 2- 5) 32bad- 1, finished in the Tertiary volcanic rocks, shows small rises of water level only a few hours after a rainstorm over the area. The water level in one of the nonflowing thermal springs near Midway ( see p. 21) also rises rapidly in response to rain or snowmelt in the mountains. Movement As has been indicated, water moves through the consolidated rocks readily, principally along the abundant zones of fracturing and solution openings. The direction of movement is, in general, downhill from recharge areas in the mountains to discharge areas near the margins of the valleys. Whether any appreciable amount of water leaves the study area through the consolidated rocks is difficult to ascertain, but an unbalance of 17,000 acre- feet per year in the gound- water budget for Heber Valley is probably due to movement out of the valley through the consolidated rocks. The structural feature most commonly suspected of draining water from the area is the Charleston thrust fault, which passes entirely through the Wasatch Range. Deer Creek Reservoir, on the Provo River, lies directly across the outcrop of the Charleston and associated Deer Creek thrust fault ( see pi. 2), and the water budget for Deer Creek Reservoir ( see p. 8) indicates that there is no loss of water from the reservoir along the thrust planes. Because there is no detectable movement of water from Deer Creek Reservoir down the Charleston thrust fault, it is probable that no significant amount of ground water leaves the study area along the fault. 20 - |