A Field Investigation in Oklahoma-Arkansas

Interim Report on the Hydrogeologic Investigations on the Occurrence of Diagenetic Siderite within the Atoka Sandstone, near Pocola, Oklahoma and Hackett, Arkansas

by

Michael D. Campbell, P.G., P.H.,
Thomas Alexander, P.G., and
M. David Campbel, P.G.

Sponsored by:
M. D. Campbell and Associates
Houston, Texas

The following photographs, figures and tables summarize the results to date of long-term investigations on the hydrogeology of the sedimentary sequences containing siderite in the Upper Atoka Formation in the Arkoma Basin of Eastern Oklahoma and Western Arkansas. The foundation for this work was completed in 1976 by Michael D. Campbell at Rice University for a Master's degree. Subsequent work was completed in 1990. Additional samples of the siderite zones were obtained in the field by Mr. Campbell and Mr. Thomas Alexander, and were used for studies on remnant magnetism at Texas A&M University Geophysics Lab conducted by M. David Campbell and for geochemical characterization via analyses by a local laboratory. The preliminary results were presented at the GSA Section Meeting at Oklahoma State University, Stillwater, OK, March, 1990 and subsequently published in Oklahoma Geological Notes, March, 1991.

Please note that the figures, maps and tables are large graphics files and may require some time to download unless a high-speed modem is used. Although inconvenient for slow modems, this is to ensure that the graphics are of sufficient size to be clear and can be viewed with ease.

Some of the available information on this project has been presented below:

General Location of Project Areas

Geologic Map of Project Area

Measured Section
Hackett Area of Project (Click on Figure for Full View Section Description).

Measured Section
Pocola Area of Project (Click on Figure for Full View Section Description).

Hackett Section Siderite Occurrences                 Pocola Section Siderite Occurrences




Additional Pocola Section Siderite Occurrences

Hackett Section Grain-Size Variations           Pocola Section Grain-Size Variations

X-Ray Diffractograms for Hackett             Pocola Siderite Samples

Hackett Outcrop Photographs

Miscellaneous Photographs

X-Ray Diffractogram Summary Data

Fossil Fragments Replaced by Siderite

Summary of 1976 Investigations:

Tentative Classification of Siderite Occurrences





Additional Investigations - Field Sampling
January, 1990

New Paleoenvironmental Interpretations:

Geochemical Data (Under Construction):

Raw Data (for comparison with above fields):

Remnant Magnetism

The results of remnant magnetism studies will be presented in due course. Preliminary results indicate that because the siderite does not oxidize due to the fixing role of the SiO2 present as matrix material, the AF Demagnetization Treatment (i.e., 0 to 999 oersteds) shows that the samples exhibit high coercivity:

AF 0: 6.45 x 10-5 emv Initial state, Std.Dev.: 0.6
etc. to:
AF 999: 5.94 x 10-5 emv final state, Std.Dev.: 0.6

Type I siderite (that which occupies ripple mark troughs) exhibits remnant magnetism that appears to have persisted though time with a measured and corrected maximum moment intensity of 8.39 x 10-5emv.

AF treatment data and data for the x, z, & z axes will be presented in due course.