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<br />. <br /> <br />. <br /> <br />. <br /> <br />",","" <br />2.~'j , <br />The medial silty member is about 20 feet thick in <br /> <br />\ <br /> <br />the McElmo Canyon area. Three water wells near Towaoc <br /> <br />penetrate from 10 to 20 feet of a silty sandstone, which is <br /> <br />considered by the writer to be the medial silty member of <br /> <br />the Entrada. The member may not be present everywhere ~n <br /> <br />the subsurface in the area. <br /> <br />The upper sandstone unit of the Entrada ranges from <br /> <br />white to grayish orange pink (lOR8/2) to moderate reddish <br />orange (lOR6/6). It is composed of very fine- to fine- <br /> <br />grained, and some medium-grained subrounded to subangular <br /> <br />clear quartz. The unit is highly crossbedded, ranging <br /> <br />from small to medium scale, but some beds exhibit horizontal <br /> <br />bedding planes. The Entrada weathers to form a prominent <br /> <br />characteristic "slick rock" rounded cliff. <br /> <br />According to Ekren and Houser (1958, p. 74), the <br /> <br />upper unit of the Entrada is 70 to 80 feet thick in the <br /> <br />McElmo Canyon area. The upper sandstone member of the <br /> <br />Entrada, determined from cuttings from a well drilled at <br /> <br />Towaoc, is approximately 80 feet thick. <br /> <br />No fossils are known from the Entrada other than <br /> <br />dinosaur footprints near Moab, Utah. At the type locality, <br />the Entrada is considered to be Late Jurassic from its <br />position between the Middle and Upper Jurassic Carmel <br />Formation and Upper Jurassic Curtis Formation (Gilluly <br />and Reeside, 1928, p. 78). <br /> <br />"1 <br />