GRADIENT ANALYSIS METHOD FOR FAULT DETECTION IN THE ROME TROUGH

Faulting in the sedimentary formations that make up the Rome trough beneath Southeastern Ohio and Eastern Kentucky was caused by the mountain building processes uplifting the Appalachian Mountains over 300 million years ago. Though generally inactive at present, these faults reflect zones of weakness within the basement rocks activated by current crustal stresses. With the increase in subsurface engineering in Ohio and Kentucky, the detailed structure of rock units deep within the Rome trough is becoming more important for aspects of oil and gas migration and recovery, CO₂ sequestration, and waste injection. As of now, because of the immense depth of the Rome Trough there is little knowledge of the fault structures present in the units overlying the Precambrian bedrock. Knowing the position and orientation of deep fault structures allows engineers to better estimate pathways for subsurface fluid and gas migration. Important information such as fault plane surface area and trend lines can be important in earthquake prediction and crustal stress studies. The amount of information known about a unit of rock correlates to the depth the unit is below the surface.

The purpose of this research is to develop a more detailed view of deep fault structures from readily available data. Using the grid manipulation software Mirone, isopach and structural data can be analyzed to locate faults occurring in the overlying Cambrian and Ordivician age rock units. Mirone is an in-depth grid operation and analysis program with the capability of finding the total gradients of image files cropped from gridded data. This isolates the areas of the largest offset in the dataset and after adjusting the color palette the faults show up as lines in the dataset. Fault lines can then be traced in Geographical Information Systems (GIS) software. Georeferencing for accurate location, fault tracing and map-making is done using ArcGIS. Upon conclusion, these data will be useful for anyone in need of a comprehensive understanding of the structures found in the Rome trough. Future work will include the 3-dimensional mapping of Rome trough faults to better demonstrate the physical statistics, detail and nature of the faulting and bedding planes involved.