| OCR Text |
Show WINTER 2013 UHQ pp 4-90_UHQ Stories/pp.4-68 12/5/12 9:38 AM Page 48 uTAH HISTORICAL QuARTERLy The location of oolite limestone quarries in Sanpete County. The quarry locations are indicated by an open square. The shaded area indicates the oolite limestone AuTHOR exposures in the county. stone for construction mater ial an attractive endeavor. Sanpete Valley formed as a result of faulting on the Valley Fault on the west side of the valley. The west side of the valley dropped downward for ming the valley and tilting the sedimentary layers upward to the east on what is known as the Wasatch Monocline, which extends seventy miles from Milburn to Salina. 5 The minimum age of the monocline is thirty-eight million years.6 The underlying Flagstaff Limestone is also tilted upward to the east, and makes up much of the upper surface of the Wasatch Plateau.7 Erosion by westward flowing streams removed much of the Green River Formation from the Wasatch Plateau and exposed the Green River Formation at the base of the plateau. The stone sometimes deteriorates with time due to freezing and thawing of water in the stone pores, groundwater attack, and chemical attack by industrial gases. Water trapped in moist limestone expands when frozen and causes deterioration. Also, ground water chemically attacks the limestone. Carl J. Christensen studied the response of the stone to atmospheric sulfur derived from industrial sources. In a series of laboratory experiments and examination of deteriorated stone on the University of Utah Park Building, he found that atmospheric sulfur reacted with the limestone to form hydrated calcium sulfate mineral, gypsum. The gypsum replaced the 5 Weiss and Sprinkel, Geologic Map of the Manti; Irving J. Witkind, Malcolm P. Weiss, and Terrence L. Brown, Geologic Map of the Manti 30’ x 60’ Quadrangle, Carbon, Emery, Juab, Sanpete, and Sevier Counties, Utah (U. S. Geological Survey Miscellaneous Investigation Series Map I-1631, 1987). 6 Shelly A. Judge, “The Origin and Evolution of the Wasatch Monocline, Central Utah,” (Ph. D. Dissertation, Ohio State University, 2007), 180, 329. 7 Hellmut H. Doelling, Paul A. Kuehne, and Douglas A. Sprinkel, Interim Geologic Map of the Ephraim 7.5-minute Quadrangle, Sanpete County, Utah, Open-file Report, 556 (Salt Lake City: Utah Geological Survey , 2009). 48 |
