Prepared by the Dallas Geological Society for American Association of Petroleum Geologists,

Annual Convention, Dallas, TX, April, 1993. (Reprint by Arkansas Geological Commission, 1993).

This guidebook presents the geologic setting of the Stanley Group, Jackfork Group, Johns Valley Shale, and Atoka Formation, with particular emphasis on the Jackfork, its stratigraphic position and age, paleoenvironmental interpretations of the Jackfork, organic chemistry, petrography, deep-sea sedimentation processes and facies (turbidity currents, debris flows, liquified flows), and outcrop gamma-ray logging. The following stops are described and interpreted with reservoir implications and sandstone/shale ratio given: Big Rock quarry, North Little Rock, Pulaski County; I-430 roadcut, Little Rock, Pulaski County; Visitor Center, Pinnacle Mountain State Park, Pulaski County; Murray quarry, near Arkadelphia, Clark County; DeGray Lake Spillway and Lake DeGray Intake, Bismarck, Clark County; Hollywood quarry, north of Hollywood, Clark County; and Dierks Lake Spillway, near Dierks, Howard County.

The guidebook includes:

• Roadmap depicting site locations during 3-day trip
• Regional geologic map, stratigraphic column, and structural and stratigraphic relationships of pre-Atokan units in central Arkansas
• Correlation chart for Mississippian and Pennsylvanian formations between deep-water Ouachita Trough and shelfal areas to the north
• Paleogeographic map showing the probable source areas and distribution systems for early Morrowan Jackfork sediments in the Ouachita Trough
• Table depicting organic geochemistry of Jackfork samples from Arkansas and Oklahoma
• Table summarizing the major mineralogic components and textural data for 16 samples from the Dierks Lake Spillway west and 43 samples from the DeGray Spillway east and west localities
• Photographs depicting the sampling and results of sonde gamma-ray and hand-held gamma-ray spectrometer logging of outcrops, with overlay of actual logs generated
• In Appendix I, worldwide sedimentary basins with hydrocarbon production from turbidite systems (5 tables, 5 maps)
• In Appendix II, spreadsheets of petrographic data from 59 samples from DeGray Lake and Dierks Lake spillway exposures, including several cross plots and ternary plots

*Includes: 141 pages, 90 figures, 9 tables

Guidebook 93-1 (52 MB)