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The AAPG/Datapages Combined Publications Database

GCAGS Transactions

Abstract


Gulf Coast Association of Geological Societies Transactions
Vol. 46 (1996), Pages 475-475

Abstract: Stratigraphy, Facies, and Environment of Deposition of the Yates Formation, North Ward Estes Field, Ward County, Texas

Ronnie D. Johnson (1), James M. Mazzullo (2)

ABSTRACT

The Artesia group is an interbedded sequence of sandstone, shales, carbonates and evaporites that was deposited in back reef and lagoonal settings of the Permian Basin during Late Permian time. The environment of the carbonate and evaporites in this group are well established but questions about the origins of the clastics and the effects of sea level and sediment supply fluctuations on their accumulation persist. This study of core, well logs, and petrophysical data of the Yates formation or the Artesia group from North Ward Estes Field provides the opportunity to address these questions.

The Yates is composed of four clastic and one carbonate facies. Facies 1 consists of well sorted fine sandstone and coarse siltstones that are non-fossiliferous and contain wavy parallel laminations. This facies is interpreted as an eolian erg deposit. Facies 2 consists of fine sandstones and coarse siltstones with clay drapes, flaser beds and no bioturbation which are interpreted as fan-delta plain deposits. Facies 3 consists of reddish brown fine sandstones with bioturbated and haloturbated structures that are interpreted as clastic-dominated sabkha deposits. Facies 4 consists of fining-upward beds with pebbles at their bases and clay laminations atop which are interpreted as fluvial-channel deposits. Facies 5 consists of bioturbated carbonate mudstones that are interpreted as shallow marine deposits.

The deposition of the Yates clastics began during a sea level lowstand and continued during a subsequent sea level rise. This in indicated by the sharp basal contact between the clastic-rich Yates and the carbonate-rich upper Seven Rivers, and the thick anhydrite bed that marks the top of the Yates. In addition, there is evidence for cyclic deposition of the clastics and carbonates in the Yates that resulted from changes in sediment supply and the shifting of depocenters.

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ACKNOWLEDGMENTS AND ASSOCIATED FOOTNOTES

(1) Dept. of Geology and Geophysics, Texas A&M University 77843-3115

(2) Dept. of Geology and Geophysics, Texas A&M University, College Station, Texas 77843-3115

Copyright © 1999 by The Gulf Coast Association of Geological Societies