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

ABSTRACT: Fluvial and Deltaic Facies in the Queen Formation, Permian Basin of Texas and New Mexico: An Overview

The Queen Formation is a sequence of carbonates, evaporites, and clastics that was deposited on the backreef shelves of the Permian basin during the Late Permian. A 7-year study of cores of the clastic members of the formation showed that they were largely deposited in desert fluvial and deltaic depositional environments during lowstands of sea level. This paper summarizes the facies characteristics of these environments.

Three fluvial-deltaic facies can be distinguished for the clastic members of the Queen. The first is composed of light to dark gray, fine to very fine-grained sandstones and silty sandstones with cross-beds, ripple cross-laminae, and planar and wavy laminae. This facies forms thin wavy sheets that thicken and thin along linear dipwise trends, and was deposited in the channels and cross-channel bars of sandy braided streams. The second facies is composed of reddish-brown, very fine to fine-grained sandstones, silty sandstones and siltstones with ripple cross-laminae, planar and wavy laminae, cross-beds, clay drapes, and pedogenetic cutans, as well as some reddish-brown siltstones and silty mudstones with haloturbation structures and evaporite nodules. This facies forms thick sheets, an was deposited in poorly channelized fluvial sandflats and adjacent fluvial-dominated continental sabkhas. The third facies is composed of cyclic deposits of poorly stratified and haloturbated silty mudstones that grade into siltstones, silty sandstones, and very fine-grained sandstones with cross-beds, planar and wavy laminae, haloturbation structures, and evaporite nodules. Each cycle forms a thick lobate body that is bounded above and below by thick-bedded evaporites and which was deposited in poorly- channelized sheet deltas that gradually filled a back-reef lagoon.

The paper will conclude with an analysis of the role of depositional and diagenetic processes in the formation of

sandstone reservoirs within the Queen Formation, and a brief summary of their reservoir properties.

AAPG Search and Discovery Article #90994©1993 AAPG Southwest Section Meeting, Fort Worth, Texas, February 21-23, 1993.