Radial outflow and unsteady retreat of late Wisconsin to early Holocene icecap in the northern Long Range upland, Newfoundland

A swampy very low-relief drift terrain along the medial zone of the northern Long Range Mountains passes outward into fresh glacially eroded bed rock of low to moderate relief. Striations, crescentic gouges, lunate fractures, streamlined stoss-and-ice surfaces, erratics, and other evidence in the upland abundantly reveal radial outflow from a late-glacial icecap that was centered over the Long Range and discharged through peripheral fjord-like valleys to coastal lowlands. A discontinuous belt of moraines and concentrated boulders delineates a still-stand or readvance after the icecap had retreated entirely to the upland and was about 50 km broad. Relatively thick till and an abundance of boulders in the medial low-relief zone suggest that after further contraction to 10 to 15 km wide, the icecap contracted rather slowly. These upland moraines may correlate with cool intervals 11,000 to 9,000 yr ago in the oxygen-isotope record of the ice core from Camp Century, Greenland, or with glacier advances 9,000 to 8,000 yr ago in Greenland and the Canadian Arctic.