Relict iceberg keel marks on the New Jersey outer shelf, southern Hudson apron

Swath sonar bathymetry reveals sinuous furrows, < 100 to > 400 m wide, kilo meters long, and <1 m to >4 m deep inscribed in semilithified clays on the southern Hudson apron. We interpret these as keel marks created by floating icebergs detached from the retreating Laurentide ice sheet since ca. 25 ka , Keel-mark orientations suggest two phases of iceberg rafting, These phase s could correlate with Heinrich meltwater events H2 and H1 ca. 25 and 17 ka , bracketing the late Wisconsinan glacial maximum ca. 22 ka. During Holocen e transgression, some keel marks were reworked and reformed into oblique ri dges where older, sandier sediments crop out at the seafloor. Relict glacia l features on the New Jersey outer shelf provide a tie between the timing o f Laurentide glacial retreat and the evolution of shallow stratigraphy on t his mid-latitude shelf during the last global sea-level cycle (ca. 120 ka t o present).