Skip to Main Content
Book Chapter

Organic and Authigenic Mineral Geochemistry of the Permian Delaware Mountain Group, West Texas: Implications for the Chemical Evolution Of Pore Fluids

By
Phillip D. Hays
Phillip D. Hays
United States Geological Survey, Water Resources Division, 401 Hardin, Little Rock, Arkansas 72211
Search for other works by this author on:
Suzette D. Walling
Suzette D. Walling
Department of Geology and Geophysics, Texas A&M University, College Station, Texas 77843–3115
Search for other works by this author on:
Thomas T. Tieh
Thomas T. Tieh
Department of Geology and Geophysics, Texas A&M University, College Station, Texas 77843–3115
Search for other works by this author on:
Published:
January 01, 1996

Abstract

Aqueous species derived from first-order degradative reaction of organic material can modify Eh and pH conditions in the late burial environment, regulate solubility of minerals and dissolved constituents in the rock/water system and release organically bound metals imo pore water as thermal stress associated with burial progresses. This study evaluates the role of organic matter alteration in Controlling late burial diagenetic processes in the Delaware Mountain Group, a sequence of rocks that presents a unique opportunity for the study of coupled organic-inorganic diagenesis. The Delaware Mountain Group lies within the Permian Basin of west Texas and southern New Mexico and includes, in descending order, the Bell Canyon, Cherry Canyon and Brushy Canyon Formations. Characterization of mineral and organic geochemistry and study of natural geochemical tracers in the Delaware Mountain Group provide evidence of the organic drive for diagenetic processes in these rocks. Delaware Mountain Group siltstone organic matter is of a sufficient abundance, of suitable type and of a sufficiently advanced state of thermal maturity to have had the potential to generate organic acids and other thermogenic products capable of controlling pore-fluid chemistry and impacting diagenetic processes. The organic matter has yielded fluids associated with thermal stress; geochemical fossil and stable isotope correlation of siltstone organic matter with oii in Delaware Mountain Group sandstone reservoirs shows that the sillstones were the source of much of the oil. Mineralogic evidence of the role that organically-derived Compounds played in late diagenetic processes includes the presence of abundant authigenic titanium oxides in these sandstones. The formation of authigenic titanium oxides indicates that titanium mobility was elevated by formation of organometallic titanium complexes—the only natural mechanism for enhancing titanium solubility. Finally, natural isotopic (carbon isotopes) and inorganic tracers (Mn, Zn, Ni, Co, V and Cr) establish a source/sink relation between the organic matter in the siltstones and authigenic minerals in the sandstones. The relation is manifest in the isotopic and minor element content of late stage authigenic products that formed in pore fluids whose chemistry was controlled by organic malter degradation. The various lines of evidence indicate that fluids carrying the products of organic matter degradation moved from the organic-rich siltstones into the sandstones where authigenic products formed and preserved a record of ambient pore-water chemistry.

You do not currently have access to this article.

Figures & Tables

Contents

SEPM Special Publication

Siliciclastic Diagenesis and Fluid Flow: Concepts and Applications

Laura J. Crossey
Laura J. Crossey
University of New Mexico Albuquerque NM
Search for other works by this author on:
Robert Loucks
Robert Loucks
ARCO Exploration Production Technology Piano TX
Search for other works by this author on:
Matthew W. Totten
Matthew W. Totten
University of New Orleans New Orleans LA
Search for other works by this author on:
Peter A Scholle
Peter A Scholle
Editor of Special Publications Special Publication No 55
Search for other works by this author on:
SEPM Society for Sedimentary Geology
Volume
55
ISBN electronic:
9781565761780
Publication date:
January 01, 1996

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal