Depositional Environment of the Updip Smackover Area of East Texas, by Hugh J. Mitchell-Tapping, Pages 79 - 86
from:
East Texas Geological Society Publication: The Jurassic of East Texas, Edited by Mark W. Presley
Copyright 1984 by East Texas Geological Society. All rights reserved.

Depositional Environment of the Updip Smackover Area of East Texas

Hugh J. Mitchell-Tapping
Sun Exploration & Production Co.,
P.O. Box 340180,
Dallas, Texas 75234

ABSTRACT

The updip Smackover region in East Texas is a complex area close to the erosional edge of the Jurassic Gulf Basin. Near this erosional edge, some areas such as Arkansas have been relatively heavily explored for hydrocarbons. Other updip areas, such as East Texas, have been sparsely drilled but even in these areas there has been some limited success. One of the keys to successful exploration in this trend is the use of seismic; another is petrology and the understanding of the depositional environment. Without the understanding of the rocks of this particular environment, most drilling should be considered random and any success may be due to luck more than to skill and the application of geology. In this study there was examination of many Smackover cores from the updip area of the Jurassic Gulf and particularly the updip area of East Texas. Observations of biota, particle types, lithology, and diagenesis have allowed determination of depositional environments. Smackover depositional environments in this area were mainly tidal carbonate mud flats. In East Texas, rivers influenced local updip areas. In certain downdip areas ooid shoals and eolian ooid dunes were formed and subjected to post-depositional leaching and other geochemical processes. By applying an actual modern analog in which these depositional environments and physical processes are presently occurring, a greater understanding of this updip area of the Smackover limestone can be attained.