The sediments and stratigraphy of the East Coast continental margin : Georges Bank to Norfolk Canyon

The continental shelf off the northeastern coast of the United States was the first ofour offshore coastal areas to be charted in detail by the Coast and Geodetic Survey,starting on Georges Bank in 1930. The techniques responsible for this increased accuracyin offshore waters were first described by Rudé (1938) and have been constantly improved.From these soundings Veatch and Smith (1939) compiled their set of contourcharts aided by a grant from the Penrose Bequest of the Geological Society of America.These soundings reopened the submarine canyon problem first commented upon byDana (1863), which had gradually lapsed into obscurity from insuffcient data. Thereader is, of course, well aware of the major controversy, with all its far reaching implications,which has been precipitated since the 1930 surveys of Georges Bank were broughtto the attention of geologists by Shepard (1933).As more of the new surveys were completed, data from the field sheets were kindlyfurnished by the U. S. Coast and Geodetic Survey to the Woods Hole OceanographicInstitution for use in dredging and coring operations. This field work, first reported in1936, was continued from time to time until 1941 as new soundings became available.Rock dredging and coring has been carried out in every major canyon on the slope fromCorsair Canyon at the tip of Georges Bank to Norfolk Canyon off the entrance to theChesapeake (Fig. I). Numerous cores have also been taken from the areas in between;and while the whole slope from Georges to the Chesapeake has not been covered, it isbelieved that no significant areas have been missed. In fact, cores from the slope takenduring the summers of 1940 and 1941 have yielded results that are corroborative ratherthan new. In 1938 on a cruise from Hudson Gorge to Norfolk Canyon, cores weretaken on the slope in areas which Veatch had considered to be the most important(personal communication).In the following report the tows and cores will be described by areas from GeorgesBank southwards, as the same region was revisited in successive years. The varioussamples, however, will be referred to by number followed by the year in which they weretaken. The material is in storage in the Woods Hole Oceanographic Institution and inthe Museum of Comparative Zoology at Harvard University.The late Joseph A. Cushman was kind enough to identify the Foraminifera whichhave been obtained in tows from the canyon walls and in cores, except for those describedin Appendix A which is contributed by Fred B Phleger, Jr. Most of the type materialis in storage in the Museum of Comparative Zoology, although at the present writingsome is in the Cushman Laboratory in Sharon, Massachusetts. I am indebted to LloydW. Stephenson for identifying a molluscan fauna from one of the canyons, and to W. C.Mansfield who has reported on another formation. Numerous discussions with Percy E.Raymond have, as usual, proved most helpful, and thanks are also due to Eugenia C.Lambert for performing the mechanical analyses and to Constance French for otherlaboratory assistance. Phleger (1939, 1942, 1946) has previously published on the Foraminifera from the slope and deep water cores. This material is, at present, atScripps Institution of Oceanography.