Seismic prospecting in the English Channel and its geological interpretation

Abstract

Summary Recent geological information obtained by core sampling in the English Channel off the South Devon coast is set forth. This information has been combined with the results obtained from a seismic survey along a line southwards from Plymouth. The evidence from these two sources points to the existence of a trough filled with New Red Sandstone deposits which extends from within a few miles of the English coastline to a point south of the middle of the Channel. The thickness of these deposits reaches approximately 3000 feet. The line of reefs formed of metamorphic rocks extending from Bolt Tail to the west of the Eddystone projects through the New Red Sandstone formations, which appear to be swamping an irregular topography. Southwards from the Eddystone the breccias and sandstones of the Permian and Trias are followed by Keuper Marl and a small thickness of Lower Jurassic formations. These in turn are covered unconformably by a few hundred feet of Chalk.