MALICSE, A., and J. MAZZULLO, Texas A&M University, College Station, TX

ABSTRACT: Pedogenetic Features in Sandstones of the Queen Formation, Permian Basin

The Queen Formation is a sequence of carbonates, evaporites, and sandstones that was deposited across the back-reef shelves of the Permian basin during the late Permian (Guadalupian) time. The origin of carbonates and evaporites in the formation are fairly well understood: they were largely deposited in back-reef sand flats, lagoons and coastal sabkhas during relative sea level high stands. However, there is some question as to whether the sandstones were deposited in similar high-stand environments or in continental environments that prograded across the back-reef shelves during sea level low stands.

Petrographic and SEM analyses of the sandstones from four fields in the Northwest Shelf and Central Basin Platform reveal that they contain four classes of features that are common to modern desert soils: textural, crystalline, fabric, and depletion pedo-features. The textural pedo-features are characterized by translocated clay, which occur as grain and link cappings, pendents, and infillings. The crystalline pedo-features consist of displacive anhydrite and halite nodules within the sandstones, and the fabric pedo-features consist of distorted primary stratification that resulted from the precipitation and dissolution of these salts. The depletion pedo-features consist of dissolved and altered minerals as well as early authigenic and replacement minerals such as hematite, authigenic clay, and carbonates.

The presence of such pedogenetic features in the sandstones of the Queen Formation supports the prevailing model that these sandstones were deposited on continental desert environment.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.