2009 Portland GSA Annual Meeting (18-21 October 2009)

Paper No. 23
Presentation Time: 9:00 AM-6:00 PM

3-D GEOLOGIC MODELING OF AN IN SITU URANIUM PROJECT, SOUTH DAKOTA


HOCKING, Crystal M., RESPEC Water and Natural Resources, P.O. Box 725, Rapid City, SD 57709 and MINNICK, Matthew, Geology and Geological Engineering, Colorado School of Mines, 1516 Illinois Street, Golden, CO 80401, crystal.hocking@respec.com

Powertech Uranium Corporation has proposed to conduct in situ mining within a uranium-enriched ore deposit known as the Dewey-Burdock project. The project is located on the southwest flank of the Black Hills, approximately 12 to 15 miles north-northwest of Edgemont, South Dakota. A comprehensive understanding of the geology is required for permitting, conceptual geohydrologic model, mine design, ore reserve calculations and public relations visualization. A 3-D geologic model for the proposed permit area was built in Mining Visualization Systems (MVS), a 3-D visualization software package by C Tech Development Corporation. Model data consists of approximately 4,000 historical Tennessee Valley Authority (TVA) exploration holes, and interpreted ore grade maps augmented with data from the current exploration process. The model targets the consolidated sedimentary rocks of Jurassic and Cretaceous age that comprise and bound the Inyan Kara group which hosts the Uranium ore. A general 3D stratigraphic model was built to create isopach and structure contour maps and constraining surfaces for an ore interpolation grid. Detailed lithologic submodels were built along the ore body to identify ore bearing sand units, confining aquitards and generate cross-sections. Interpolated ore bodies were generated to facilitate well field design and reserve calculations. An ESRI geodatabase contains the model data and products for distribution via an ArcServer based website and ArcExplorer.