ABSTRACT
Field and air photo investigation of the Arkansas Valley seismic swarm area in 1982 resulted in the detection of a northeast-trending lineament which dissects the swarm region and may be indicative of the fault which is the source of the recent seismicity. The linear coincides with the alignment of portions of several drainage systems along much of its length, and in other places it is defined by escarpments a few feet high. The possible relationship of the linear to local and regional structures and seismicity will be discussed. Additional features consisting of ground cracks, sinks, and a relatively fresh-appearing scarp in the vicinity of a known fault in the swarm area will also be discussed. This study was funded by the Arkansas Geologic Commission and the Geology Department of Southern Illinois University.
