A Fault Kinematic Analysis with Observations Pertaining to Fault Trends within the Core of the Arbuckle Anticline, Southern Oklahoma, USA
The Arbuckle Mountains, located within south-central Oklahoma, have been the focus of numerous studies concentrating on the structural evolution of the North American Continent. The Arbuckle Anticline, located in the western area of the Arbuckle Mountains, is well recognized as an uplift from the Ouachita Orogen (Dott 1933; Ham 1951; Ham 1973; Tanner 1967). Efforts were made (Brewer et al. 1983; Ham 1951; Ham 1969; Granath 1989; Tanner 1967) to document the major structural features in an attempt to summarize the deformation history of the Arbuckle Mountains. However, the smaller-scale structural features along Interstate 35 have mostly been overlooked in these studies. There has been no notable attempt to give a complete kinematic analysis of the Arbuckle Anticline or to determine what type of strain has affected the region on an outcrop scale. Numerous faults and other features are undocumented, and displacement directions have been inconclusively assessed (as determined by recent gathering of slickenline data).
The focus of this study is on the core of the Arbuckle Anticline along Interstate 35 at Mile Marker 48. The outcrop has exposures of the Ft. Sill Limestone and Royer Dolomite. The methods to analyze this outcrop include geologic mapping, panoramic annotations, kinematic analysis, and fracture analysis along the outcrop. These methods were used to determine the dip-slip versus strike slip motion at the core of the anticline, temporal relationships between the fractures sets and the deformation, and if the structures found within the core are kinematically compatible with the rest of the Arbuckle Anticline. Data from a Master's student's project (Hessert 2016) were used in conjunction with the data presented here to allow for compatibility comparisons between the core of the anticline and the limbs.
The results are as follows: (1) Kinematic analysis from fault striae within the anticline core show a greater occurrence of strike slip movement to dip slip movement consistent with reverse and oblique left-lateral strike slip motion and displacement; (2) The Arbuckle Anticline core contains the Ft. Sill Limestone interleaved with the Royer Dolomite in a previously unrecognized imbricate; (3) Shallowly plunging fold hinges throughout the core are parasitic, indicate left-lateral rotation, and define the hinge of the Arbuckle Anticline as NW-SE; (4) both pre-folding and post-folding fracture sets can be differentiated and indicate a maximum principle stress direction of N41E; (5) structures along Mile Marker 48 are found to be kinematically compatible on an outcrop scale as well as throughout the rest of the anticline.
AAPG Datapages/Search and Discovery Article #90250 © 2016 Southwest Section AAPG Annual Convention, Abilene, Texas, April 9-12, 2016