Flood surfaces and deflation surfaces within the Cutler Formation and Cedar Mesa Sandstone (Permian), southeastern Utah

Abstract

Areally extensive erosion in eolian deposits have been interpreted as long hiatuses in eolian deposition. Such erosion form during deflationary episodes or during periods of erg stabilization or contraction. They are called surfaces and can be useful for stratigraphic correlation because of their regional extent. The Permian Cedar Mesa Sandstone and Cutler Formation contain a type off super surface (herein termed surfaces), ∼10-400+ km2. Flood form as a result of fluvial floods into active dune seas. The may expand through nonclimbing migration of eolian dunes but do not imply long hiatuses in eolian deposition as do other types of super surfaces. Cutler and Cedar Mesa flood are overlain by shales and sandstones which thicken laterally and merge with fluvial channel-fill deposits. Flooding of active dune fields in the Cedar Mesa Sandstone is suggested by intertonguing of eolian dune and fluvial deposits. Flood can easily be mistaken for deflationary super but are distinguished by evidence of dune migration coincident with flood events and by an increase in the number of adjacent to associated aqueous deposits.