Improving Structure Contour Maps: Regional Structural Elements of the Nashville and Jessamine Domes Using Automated GIS Tools

Kenneth S. Boling1, Robert D. Hatcher Jr.1, Gary G. Bible2, Peter J. Lemiszki3, Andrew L. Wunderlich1, Morgan M.Strissel1

1 Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 2 Cougar Dome, LLC, P. O. Box 133, Helenwood, TN 3 Tennessee Division of Geology, 3711 Middlebrook Pike, Knoxville, TN Project Goals • Identify small, map-scale structural features along the Nashville and Jessamine domes

• Develop a process to automate the integration of large surface and subsurface geologic datasets

• Relate these features to tectonic events before and after the deposition of the Chattanooga-Ft Payne

• Relate these structures to oil and gas accumulation Study Area KY

TN Silurian Outcrop Small-Scale Structural Feature on the Nashville Dome: Truncation of a Pre-Chattanooga Syncline Containing Silurian Rocks

Wilson et al., 1964, Geologic map of the Columbia quadrangle Generalized Stratigraphy Deicke K-Bentonite (Pencil Cave) Unconformity Ordovician Volcanic Ash Beds: K-Bentonites

• High Th, K Regional extent of Bentonites • Regionally extensive

Millbrig K-Bentonite (Mud Cave)

Deicke K-Bentonite (Pencil Cave)

(Haynes, 1994) Chattanooga Shale (Ohio, New Albany)

• High U • Regionally extensive • Easy to spot on a log

Aeroradioactivity Gamma Ray Log National Uranium Resource Evaluation (NURE) Data Compilation

Well Logs Online databases and map services Digitized Maps

Scanned Maps

Offline databases Drilling Logs Why use Python? • Data management – New data can be added easily as soon as it becomes available

• Reproducible results – Serves as a record of exactly what was done to the data • No more having to try and remember what you did to make that “New_final_merged_tnwells_mk2.xls” file last year.

• Integrates with ArcMap

• Free! What is a structure contour map?

Lines of equal elevation or depth Combining Surface and Subsurface Data

Land Surface Topography Structure Contour of Geologic Contact

Explanation

Oil and gas well

Outcroplocation Buffalo Valley Quadrangle Hand Drawn Contours Paper Quadrangle Map Surface data collection

860ft

880 ft

900 ft Generate points at line intersections Digital Elevation Model

Get elevation data at any location!

USGS 1/3 arc-second DEM, Buffalo Valley Quadrangle, TN (2x vertical exaggeration) Elevations from contours Interpolate elevations from DEM Hand Contoured Map vs. Machine Contours

700ft

500ft ~3,000 points manually generated in 3 months

~20,000 points automatically generated in less than 20 minutes Final Integrated Dataset

• Project study area: 69,000 mi2

• Surface points (all formations): 7,200,000

• Subsurface formation top picks: 146,000 Top Knox Dolomite Top Knox Dolomite (Contoured) Top Stones River Group

5,800 wells 105,000 Surface points TopStones Stones River River Group Group (Contoured) Base Chattanooga Shale Base Chattanooga Shale (Eroded) (Contoured) Top of Nashville Group (Trenton) Top of Bigby Cannon Stones River Group, Nashville Dome Possible Faults

Fold Axis Chattanooga Shale, Nashville Dome Possible Faults S Flank of Nashville Dome, Base Chattanooga Shale w/ possible syncline axes

Fold Axis Base Chattanooga Shale with possible anticline axes

Fold Axis 3-Dimentional Surface Base Chattanooga Shale, Southern Jessamine dome, possible folds (illumination from S) Separating Pre-Chattanooga Structures from Superposed post- Silurian plus post-Chattanooga deposition

T1 T3

Pre-Mid-Silurian deposition Late Devonian – Mississippian deposition (Chattanooga Shale) T 2 T4

Post-Mid-Silurian deformation (Acadian-Neoacadian orogeny & nascent doming, Late Pennsylvanian-Early Permian (Alleghanian orogeny & renewed doming) erosion) RDH 2017 Stones River Group Stones River Group Pre-Chattanooga Structure?

No Data

No Data Additional surfaces can be contoured quickly

• Since the database contains information on every formation

• Other Horizons can be mapped quickly Monteagle Limestone, Sunnybrook anticline, Kentucky-Tennessee border Top Knox Dolomite Pencil Cave Bentonite and KY wells with high initial production rates

Ferguson Bros 9372 Top of Fort Payne Fort Payne Isopach Summary • Automating data collection and error checking allows for larger scale investigations using existing resources

• Small scale structures may be resolved at the surface

• May provide insight into events prior to deposition of Chattanooga Shale Acknowledgements Data sources Primary Advisor: Dr. Robert Hatcher Jr.

Committee members: Dr. Gary G. Bible Dr. Peter J. Lemiszki Dr. Micah J. Jessup Dr. Khalid A. Alshibli