HENRIEVILLE SANDSTONE: UPPER DUNE FACIES OF THE ENTRADA FORMATION, GARFIELD AND KANE COUNTIES, UTAH

The Henrieville Sandstone (informal name) is an aeolian coastal deposit that developed during the final stages of the Entrada Formation (Callovian) in south central, Utah. Paleogeographically the Henrieville Sandstone appears to have been deposited in the 15° to 25° North latitude zone of great deserts. The Twin Creek/Sundance Sea was located to the northwest of the area where the Henrieville was deposited. Paleowind directions within the Henrieville are consistently from the northwest quadrant. Dune formation may have been affected by trade winds, land-sea breeze, or monsoon.

The Henrieville is white, poorly cemented, sub mature, moderately sorted, fine- to medium-grained, quartzose sandstone. The sand appears to be bimodal, suggesting mixed sources. Secondary gold to bright red hematitic banding and ironstone concretions that range in size from one centimeter to one meter in diameter are widespread.

The Henrieville Sandstone is aerially restricted with outcrops along SR 12 between Cannonville and Henrieville, Utah and extending southeastward to Grosvenor Arch in Kane County, Utah. Two miles north of Henrieville, Utah along SR 12 the unit measures 58.2 meters (191 feet) thick and shows a conformable base and disconformable top. The Henrieville Sandstone is composed of wind-laid cross-bedded dunes that distinguish it from the underlying shallow marine water-laid cross-beds of the Escalante Member of the Entrada Formation. Disconformably overlying the Henrieville is a pebble conglomerate that forms the base of the Dakota Formation (Cenomanian).