The Gilmore City horizon was used because it is more continuous than the top of Mississippian, and curvature of the Mississippian surface is somewhat affected by topographic irregularities due to erosion at the pre-Pennsylvanian unconformity surface. These lineaments were interpreted on the Gilmore City horizon, and their orientations were analyzed using rose diagrams. The two maps are very similar, showing oriented sets of lineaments that appear to persist from the top of Mississippian to the base of the aquifer. The Gilmore City is the base of the Mississippian aquifer, approximately 130-180 ft (20-30 milliseconds) below the reservoir in Dickman Field. In order to search for seismic features related to fracturing in the Dickman Field Mississippian reservoir, maps of volumetric most negative curvature have been extracted from the top of Mississippian and Gilmore City seismic horizons. Groupings at higher levels indicated that areas overlying active structures may be isolated from their neighbors by this technique while passive structures showed no differences which could be isolated.Orientations of Seismic Lineaments Compared to Regional Structure Analysis of rose diagrams using a multivariate technique indicated lithology as the primary control for the lower grouping levels. Fracture trace log-mean lengths were shorter over several types of structures, perhaps due to increased fracturing and subsequent erosion. Fracture trace frequency appeared higher on the flanks of active structures and lower around passive reef structures. Analysis indicates that the lengths of fracture traces are log-normally distributed according to the mapping technique used. Composite rose diagrams of fracture traces were analyzed using a multivariate analysis method which grouped or clustered the rose diagrams and their respective areas on the basis of the behavior of the rays of the rose diagram. Fracture trace lengths and frequency (number of fracture traces per unit area) were analyzed by trend surface analysis and length frequency distributions also were compared to a standard Gaussian distribution. An analysis of fracture trace patterns in areas of flat-lying sedimentary rocks for the detection of buried geologic structure Two study areas in a cratonic platform underlain by flat-lying sedimentary rocks were analyzed to determine if a quantitative relationship exists between fracture trace patterns and their frequency distributions and subsurface structural closures which might contain petroleum.
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