Shallow sedimentary framework of Georges Bank

Two thousand nine hundred kilometers of minisparker data were collected on Georges Bank by the United States Geological Survey during October of 1975. Several sedimentary features have been observed in the data, The bank is recognized as a compound feature resulting from erosion of Tertiary coastal-plain strata followed by deposition of an extensive sediment wedge on the western flank of the cuesta. Marine planation (probably Late Pleistocene) truncated this bank morphology producing an erosion surface roughly paralleling the present sea floor. The truncated bank surface is blanketed by a veneer of complex Late Pleistocene drift which masks underlying features and is being reworked by modern processes. Present bank morphology is inferred-to be arather recent development.

A proper understanding of the significance of complex bank sediments with respect to the potential geologic hazards of drilling or placement of bottom. supported structures necessitates a more detailed seismic reflection program, in conjunction with geotechnical analysis of core-samples.