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<br />2876 <br /> <br />Entrada Sandstone <br /> <br />. <br /> <br />General characteristics.--The Entrada Sandstone was <br /> <br />named and described by Gilluly and Reeside (1928, p. 76) <br /> <br />for exposures on Entrada Point in the San Rafael Swell, Utah. <br /> <br />It is exposed in a small area in the northern part of the <br /> <br />reservation (fig. 2) and in the canyons of McElrno Creek and <br /> <br />its tributaries (fig. 8). It is in the subsurface through- <br /> <br />out the rest of the reservation. It unconformably overlies <br /> <br />the Navajo Sandstone. <br /> <br />In the Ute Mountain area, the Entrada Sandstone consists <br /> <br />or two units, a lower silty unit and an upper sandstone unit. <br /> <br />The lower unit is a very silty pale reddish-brown (lOR5/4) <br /> <br />to grayish-red (lOR4/2) to moderate reddish-brown (lOR4/6) <br /> <br />sandstone. It is composed of very fine-grained clear quartz <br /> <br /> <br />. and silt. It weathers into characteristic rounded forms, <br /> <br /> <br />commonly called hoodoos, and in places it forms a soft bench <br /> <br />between the more massive cliffs of the underlying Navajo <br /> <br />Sandstone and the upper sandstone member of the Entrada. <br /> <br />This lower unit is correlative with the medial silty member <br />of the Entrada of Harshbarge., Repenning, and Irwin (1957, <br />p. 35-38) in the Navajo country. The lower unit is similar <br />to the red silty facies of the Carmel Formation and has been <br />considered to be the Carmel by some geologists in the area. <br />In this report, the unit will be treated as the medial silty <br />member of the Entrada Sandstone. <br /> <br />. <br /> <br />J./t <br />