Continental Shelf Sediments off Eastern Newfoundland: A Preliminary Investigation
Surficial sediment samples from the continental shelf off eastern Newfoundland were analyzed for grain-size distribution (302 samples) and CaCO3 content (257 samples). The results were compared with those of previous investigations.Gravel covers the inner Grand Banks. Clean, well-sorted sand covers most of the outer banks, but significant quantities of gravel (greater than 10%) are present locally. Biogenic carbonate sand is irregularly distributed on the Grand Banks.The presence of gravel as far seaward as the shelf break indicates the Pleistocene ice sheet once extended across the Grand Banks and the sediments are relict. Other lines of evidence that indicate the sediments are relict include: a radiocarbon date of 17 000 yrs. B.P. on biogenic sand, the occurrence on parts of the shelf of littoral sand now in 90 m of water as well as glacially derived residual sediments, the presence of moraines and a Quaternary shelf sedimentary section 20–200 m thick, and the presence of relict sediments on continental...