Eolian and Fluvial Facies in Sandstones of Queen Formation, Permian Basin, Texas

J. Mazzullo, A. Malicse, J. Siegel, C. Holley, S. Bilir, S. J. Mazzullo

The Queen Formation (Guadalupian) is a sequence of carbonates, evaporites, and sandstones that is found across the Northwestern shelf and Central Basin platform of the Permian basin. Cores, logs, and thin sections of the Queen sandstones, which are commonly stratigraphic traps for oil, were examined in five fields in order to determine their sedimentation history.

The sandstones in the Queen Formation were deposited during lowstands of sea level by eolian and fluvial processes. Five facies can be distinguished on the basis of textures and sedimentary structures: (1) dune and interdune, (2) eolian sand sheet, (3) sabkha, (4) fluvial, and (5) estuarine-tidal flat facies. The dune-interdune facies is distinguished by fine and very fine sandstone with dune cross-beds, grainflow and grainfall laminae, and wind-ripple laminae. The sand sheet facies can be divided into two subfacies: a dry sand sheet, which is distinguished by silty sandstone with planar wind-ripple laminae, low-angle cross-beds, and deflation lags; and a wet sand sheet, which is distinguished by silty sandstone with eolian adhesion structures, water ripples, mud drapes, and root trac s. The sabkha facies is distinguished by fine and very fine sandstones with eolian adhesion structures, contorted beds, algal laminae, and nodular and nodular-mosaic anhydrite. The fluvial facies is distinguished by an upward-fining sequence of massive and cross-bedded fine and very fine channel sandstone overlain by ripple-laminated sheet-flood silty sandstone. Lastly, the estuarine-tidal flat facies is characterized by laminated and bioturbated siltstone.

The dune-interdune, sand sheet, and sabkha facies are present throughout the Northwestern shelf and the southern part of the Central Basin platform, whereas the fluvial and estuarine facies are restricted to the northeast part of the Central Basin platform. Of these five facies, the dune-interdune, dry sand sheet, and fluvial channel facies are consistently hydrocarbon reservoirs, while the remaining facies are non-productive.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.