INTRADUNAL DEFORMATION FEATURES FROM THE JURASSIC NAVAJO SANDSTONE

An outcrop of Navajo Sandstone in West Canyon, Arizona, provides evidence for saturated-sediment deformation within a large paleodune. Numerous liquefaction/fluidization features cut across primary sedimentary structures at this location. Two, well preserved, crocodilian fossils occur within the deformed deposits. Their taphonomy establishes the timing of the deformation event, relative to the depositional sequence, and indicates that deformation of cross-stratification occurred within a depositional bedform, above the level of adjacent interdunes. These evidences suggest that the water table configuration in the Navajo erg sometimes included topographic contours.