Show ROCK GYPSUM AT NEPHI UTAH the character occurrence and development of rock gypsum near nephi utah are considered in a paper entitled rock gypsum at nephi utah which is included in a bulletin no recently published by the united states geological survey under the title contribution to economic geology 1903 the author of this paper is mr J M boutwell who in december 1902 visited this immense deposit of rock gypsum in juab county it is the largest well known deposit of rock gypsum in utah and forms the entire mass of a prominent spur at the entrance to salt creek valley the exposed portions of this body are about feet thick feet high along the bedding and at least feet long on the strike the present paper is a portion of a more comprehensive report by mr boutwell on gypsum deposits in utah included in bulletin no entitled gypsum deposits in the united states both bulletins nos and are published for gratuitous distribution and may be obtained on application to the director of the united states geological survey washington D C the most important fact shown by anay ses of samples taken from this deposit next to the determination of their high gypsum content is that the first class rock as we well as the waste rock includes beaw between e en 22 and 23 per cent of anhydrite it is thought that the presence of anhydrite might retard the setting of the gypsum as the former acts like artificially dehydrated gypsum gyp sumi which takes up water very slowly and without hardening it is highly probable that hydrate occurs in a large per cent of other gypsum deposits so that it would be advisable to have further reliable analyses of other that have proved suitable for the manufacture of plaster of good setting quality several other deposits of value are known in the salt creek valley east of the main body the most important of this is on the north side of the creek about one halt half mile east of the nephi plaster mill they include rock gypsum of good grade grad and impure varieties the great body at the mouth of the valley is however er fhe th only gypsum deposit in utah now exploited to any considerable extent it was known klony before the town of nephi was settled and has probably been known to the whites for nearly 80 years about 35 years ago a claira claim GOO by 1500 in dimensions was forni formally ally lo 10 bated and in 1882 this was patented by john hague and others under the name of the juab plaster and mining laim claim small inter mittens shipments were made to salt lake city in 1887 under the management ot of hyde hague and whitmore and later rock gypsum was quarried and burned in sorghum pans for local consumption during the following year encouraged by the rapidly increasing demand these parties incorporated corp orated their company and erected the nucleus of the present efficient plant which though not extensive is very complete its output averages 36 tons of plaster a day and between and tons a year this includes dental casting finishing land and hard plaster each appropriately prepared for its special uses A large and increasing demand is supplied throughout the great basin region and shipments are made as far as grand junction on the east los angeles and hawaii on the south and west and victoria on the north |