RE-EVALUATING THE TECTONIC MODEL FOR THE ARBUCKLE MOUNTAINS, OKLAHOMA BY SPATIAL AND GEOMETRIC ANALYSIS OF STRATIGRAPHIC AND STRUCTURAL TRENDS

Understanding the spatial distribution and geometric relations between stratigraphy and structural features of the Arbuckle Mountains can enable reconstruction of a more accurate tectonic timeline for not only the Arbuckle Mountains, but for the assembly of modern North America. The Arbuckle Mountains in south central Oklahoma exhibit structurally complex stratigraphy associated with regional features like the Southern Oklahoma Aulacogen, the Arbuckle Anticline, and the Washita Valley Fault. The YMCA Camp Classen and the Turner Falls park in Davis, OK, host observed, but largely unmapped, small scale structural features that represent the magnitude of deformation. Mapping these features produced a tectonic model that was compared to the regional model. A highly detailed geologic map was produced to reveal the spatial continuity and characteristics of geologic units expressed on the surface. Many of these units cannot be differentiated in the field because they appear similar in outcrop. Therefore, petrographic observations of thin sections as well as XRF data were vital for informing mapping efforts. Additionally, there is a lack of detailed geologic maps for the area, which demonstrates the need for further research. Stereonets were used to aid in classifying and determining the locations and types of folds, faults, and joints. These data, and the trends they represent, were compared to the existing regional tectonic model. The new and existing models indicate different tectonic histories so a new interpretation must be considered. The fault kinematics and geometry controlled the spatial distribution of stratigraphy throughout the mapped area. These mapped features indicate a large left lateral strike-slip system associated with the Washita Valley Fault. New interpretations indicate that this system hosts the Collings Ranch basin and that it’s bounding faults are not the same as previous interpretations, that the basin is bounded on the south by the left lateral Washita Valley strike-slip fault and to the north by the Classen fault. New interpretation leads to the conclusion that the Raymond fault to the northeast of the Classen fault is the more likely northern bounding structural features for the Collings ranch basin and that the Classen fault is a normal fault associated with the negative flower structure.