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Research about Cape Ann

Source-linked reports with geographic coverage including Cape Ann.

3 recordsLinked to original sources
USGS2017

Upper Wisconsinan submarine end moraines off Cape Ann, Massachusetts

Seismic profiles across the southwest end of Jeffreys Ledge, a bathymetric high north of Cape Ann, Massachusetts, reveal two end moraines. The moraines overlie upper Wisconsinan glacialmarine silty clay and are composed mostly of subaqueous ice-contact deposits and outwash. They were formed below sea level in water depths of as much as 120 m during fluctuations of a calving ice front. The moraines are late Wisconsinan in age and were formed after the Cambridge readvance, about 14,000 yr B.P., and before the Kennebunk readvance, about 13,000 yr B.P. They represent fluctuations of the ice front during overall retreat of Laurentide ice from the Gulf of Maine and New England. ?? 1985.

Massachusetts↗
USGS1985

A drowned Holocene barrier spit off Cape Ann, Massachusetts

Seismic profiles and bathymetric contours reveal a drowned barrier spit on Jeffreys Ledge off Cape Ann, Massachusetts. Seaward-dipping internal reflectors indicate that a regressive barrier formed during the early Holocene low sea-level stillstand. Preservation of the barrier spit may have been favored by its large size (as much as 20 m thick), by an ample sediment supply from unconsolidated glacial drift, and by the subsequent rapid sea-level rise. The barrier spit is present in water depths of 50 to 70 m and indicates a low relative sea-level stand of −50 m. This value confirms the low relative sea-level stand of −47 m postulated by Oldale et al. (1983) for northeast Massachusetts and New Hampshire on the basis of the submerged delta of the Merrimack River, and it indicates that the barrier and delta were contemporaneous (Oldale et al., 1983).

Massachusetts↗