STRAIN PARTITIONING OF THE SOUTHERN ARKOMA BASIN

The Arkoma Basin is a peripheral foreland basin of the Pennsylvanian Ouachita Orogeny. The basin is structurally bounded by the Arbuckle Mountains of Oklahoma to the west, the Ouachita Mountains of Oklahoma and Arkansas to the south, and the Ozark Uplift of Arkansas and Missouri to the north. In the Southern Arkoma Basin, there are sporadic anticline and thrust pairs that occur along strike of the leading-edge thrust of the Ouachita frontal fold and thrust belt. These thrust-paired anticlines provide evidence at the surface that significant strain exists within the Southern Arkoma Basin. The partitioning of strain within the Southern Arkoma Basin moves northward away from the Ouachita frontal fold and thrust belt and produces anticlines and synclines that have broader wavelengths and shallower amplitudes. This broadening sequence reflects the northward decreasing effect of contractional strain within the basin.

This study intends to provide a better understanding of the transition from the mildly deformed to the flat lying rocks of the Arkoma Basin in order to determine the kinematics of strain partitioning in the Southern Arkoma Basin of Western Arkansas within the Ione and Barber Quadrangles. Our field checking of the available geological maps together with our interpretation of available 2-D seismic reflection lines and electric well log data suggest that the strain partitioning in the Southern Arkoma Basin was accomplished in the subsurface by a triangle zone. We plan to construct balanced structural cross-sections to calculate the amount and percentage of shortening that the triangle zone as well as the broadening anticlines and synclines have accommodated in the Southern Arkoma Basin.