This British Geological Survey (BGS) marine geophysical survey took place in April/May 1974 in the Irish Sea, Lyme Bay and St. Georges's Channel area on board the RRS John Murray. The purpose was to collect data as part of the UK regional mapping programme in conjunction with IGS Applied Geochemistry Unit. A total of 1033 km of data were collected. Sea floor data were collected using an echo-sounder and a transit sonar. Towed gamma spectrometer. Subsurface data were gathered using a sparker. Analogue data were collected and paper records were generated. Sea-bed samples and cores were collected using shipek grab and cone dredge. The data are archived by BGS. Navigation: Decca. These data are archived by BGS. See BODC cruise inventory JM6/74 for info.