Coordinated strike-slip and normal faulting in the southern Ozark dome of northern Arkansas: Deformation in a late Paleozoic foreland

Abstract

Structures that formed on the southern flank of the Ozark dome, in the foreland of the late Paleozoic Ouachita orogeny, have received little modern study. New mapping of the western Buffalo River region of northern Arkansas identifies diversely oriented faults and monoclinal folds that displace the generally flat lying Mississippian Boone Formation over a 180 m elevation range. Kinematic measurements and spatial relations reveal the presence of both east-striking normal faults and broader northeast-striking dextral strike-slip fault zones that acted in a coordinated fashion to accommodate constrictional strain, in which north-south extension was balanced by vertical and east-directed shortening. North-south extension in the Buffalo River region probably reflects Pennsylvanian–Early Permian deformation within the flexural forebulge of the developing Ouachita orogeny, which closed progressively westward along the southern margin of the craton.