Sediments, Shallow Subbottom Structure, and Sand Resources of the Inner Continental Shelf, Central Delmarva Peninsula
Author | : Michael E. Field |
Publisher | : |
Total Pages | : 134 |
Release | : 1979 |
Genre | : Continental shelf |
ISBN | : |
A data base consisting of 880, 180, and 35 kilometers (475, 97, and 19 nautical miles) each of high resolution seismic reflection, bathymetric, and side-scan sonar profilings was obtained in 1970 and 1974, along with 71 vibratory cores and 3 onshore borings. These data were analyzed to assess the resource potential of sand suitable for use in beach restoration and to establish the Quaternary evolutionary framework of the northern Delmarva inner shelf. Shallow subsurface strata consist of gently dipping Neogene sedimentary beds that conform to the gradient and direction of the Atlantic Coastal Plain and display no evidence of tectonic deformation. Eleven major acoustic surfaces, including the presumed Tertiary-Quaternary nonconformity at about -30.5 to -61 meters ( -100 to -200 feet), are present within the upper 122 meters (400 feet) of the shelf subbottom. Buried channels are common to the sea floor of the entire region; in the Delaware Bay entrance, most channels are cut to 46 meters (150 feet) below sea level and are filled laterally from both the New Jersey and Delaware shelves. Many small channels on the Maryland shelf are alined with existing onshore drainage or historical inlet sites.