HIGH RESOLUTION GRAVITY SURVEY TO DETERMINE LOCATION AND EXTENT OF FAULTS IN THE JANE 7.5-MINUTE QUADRANGLE, MISSOURI

Detailed geological and geophysical mapping of the Jane 7.5-minute quadrangle in SW MO was undertaken by a group at Missouri State University in 2012. The area is composed of Lower Ordovician and Early Mississippian limestone, dolostone, and shale. Numerous low amplitude structural features and faults were found by surficial geological mapping.

In order to further investigate these structural features, a high resolution gravity survey, including a number of profiles at 0.1 mile spacing, was conducted to determine the extent and subsurface nature of the faults in the region. An initial Bouguer gravity anomaly map shows a a general low anomaly in the northern portion of the map, and higher gravity in the southern portion which is probably caused thinning of the Paleozoic sediments toward the south. A horizontal derivative map gravity anomaly map amplifies an anomaly that lines up with an extensive surficially mapped fault. Residual gravity anomaly maps constructed using wavelength filtering and horizontal derivatives and 2-D forward models constrained by surface mapping and density measurements will be constructed in order to better understand the geometry and location of identified and unidentified faults.