In May 1986, a wide-aperture siesmic field experiment was conducted in southwestern Arkansas and northwestern Louisiana. This experiment was sponsored by the Incorporated Research Institutions for Seismology as part of the Program for Array Seismic Studies of the Continental Lithosphere. The survey line runs from the south edge of the Ouachita Mountains, out into the Gulf Coastal Plain. The experiment involved 21 shot points and two major deployments, each of 400 recorders, with an effective aperture of 200 km. The goal of the experiment was to attempt to provide constraints on the diverse development sequences that have been proposed to explain the structure of the area. The data were processed using a previously developed, prestack common source acoustic finite difference migration to produce images of reflectivity in a slice 200 km long and 40 km deep. This migration algorithm has no dip restrictions and uses a two-dimensional, variable velocity distribution for wave extrapolation. Interpretation of the results of the prestack processing, together with the results of complementary two-dimensional ray trace modeling (not shown here) of the data, provides an enhanced picture of the structure of the Paleozoic continental margin that is consistent with the observations in most previous geophysical and geological studies. The main physical and temporal features of the model are crustal thinning during Precambrian rifting, a continent-ocean boundary sedimentary wedge and carbonate bank, thrusting of deepwater sediments during the Ouachita orogeny, and Triassic rifting. ¿ American Geophysical Union 1989