Comprises details of the operations, field acquisition, results and interpretation of the seismic survey. Three seimic lines toatlling 22 miles were recorded. The survey aimed to establish closure over the Marsden structure identified in a 1968 survey. The base Permian and Middle Cambrian unconformity surface were mapped with confidence; the base Cambrian was not attempted due to lack of velocity differentiation. 150 ft of critical closure and 8 square miles of areal extent were outlined for the Marsden structure; it is part of a much larger structural trend. Earlier refraction data suggests that Cambrian lismestone is present over the northern portion of the trend.