Late Quaternary changes of level in western and southern Newfoundland
Emerged Quaternary marine features are numerous along the west coast of Newfoundland, although their distribution is patchy. They include wave-cut benches and cliffs, localized constructional forms such as beach ridges, bars, and deltas, and a discontinuous blanket of fossil-bearing marine sediments. These features reach progressively higher elevations toward the north; their positions in long east-west bays indicate a westerly component in the northward rise. The highest marine limit is very indistinctly recorded, but a lower strand line, cutting the latest glacial deposits, and rising northwestward, is well marked by wave-cut benches on weak rocks. Strand lines in intermediate positions are very weak, but wave-cut benches are well developed at present sea level. These facts indicate upwarping following deglaciation, the movement having been interrupted by one long pause and followed by another pause at present sea level. No unequivocal evidence of emergence was found along the western half of the south coast, although emergence may be recorded farther east. The northwestward rise of the marine features along the west coast is consistent with (though it does not prove) the hypothesis that part or all of Newfoundland was invaded by the Labrador ice sheet during the latest (presumably Wisconsin) glacial age and that the warping was caused principally by unloading of the crust by the Labrador ice sheet during the same glacial age. Evidence in two districts on the west coast indicates that at least part of the postglacial eustatic rise of sea level occurred while glacier ice was still actively present, and prior to at least part of the crustal warping.