Cosmogenic nuclide age estimate for Laurentide Ice Sheet recession from the terminal moraine, New Jersey, USA, and constraints on latest Pleistocene ice sheet history

Abstract

The time at which the Laurentide Ice Sheet reached its maximum extent and subsequently retreated from its terminal moraine in New Jersey has been constrained by bracketing radiocarbon ages on preglacial and postglacial sediments. Here, we present measurements of in situ produced 10Be and 26Al in 16 quartz-bearing samples collected from bedrock outcrops and glacial erratics just north of the terminal moraine in north-central New Jersey; as such, our ages represent a minimum limit on the timing of ice recession from the moraine. The data set includes field and laboratory replicates, as well as replication of the entire data set five years after initial measurement. We find that recession of the Laurentide Ice Sheet from the terminal moraine in New Jersey began before 25.2±2.1 ka (10Be, n=16, average, 1 standard deviation). This cosmogenic nuclide exposure age is consistent with existing limiting radiocarbon ages in the study area and cosmogenic nuclide exposure ages from the terminal moraine on Martha’s Vineyard ~300 km to the northeast. The age we propose for Laurentide Ice Sheet retreat from the New Jersey terminal position is broadly consistent with regional and global climate records of the last glacial maximum termination and records of fluvial incision.

Rapid thinning of the Laurentide Ice Sheet in coastal Maine, USA, during late Heinrich Stadial 1

“…At the LGM, the southeastern margin of the LIS extended into the Gulf of Maine ~600 km beyond the present coastline and onto Georges Bank (Pratt and Schlee, 1969;. Cosmogenic exposure dating indicates that the LIS margin initially pulled back from its maximum extent in southeastern Massachusetts at Martha's Vineyard, dated to 27.5 ± 1.6 ka (n = 8), and northern New Jersey, dated to 25.2 ± 1.3 ka (n = 16; Corbett et al, 2017; these ages and all those reported below are recalculated using the northeastern North American production rate from Balco et al (2009) and give uncertainties as the standard error of boulder ages and the production rate uncertainty (4.8%), added in quadrature). Several recessional moraines in southernmost New…”

Guidebook for Field Trips in Western Maine and Northern New Hampshire

“…Dyke et al, 2004), glacial varves , and cosmogenic nuclide dating (Balco et al, 2002;Balco and Schaefer, 2006;Bierman et al, 2015;Davis et al, 2015;Corbett et al, 2017;Koester et al, 2017;Hall et al, 2017;Fig. 4).…”

Applying the Cosmogenic Nuclide Dipstick Model for Deglaciation of Mt. Washington

“…Dyke et al, 2004), glacial varves (Ridge, 2004;Ridge et al, 2012), and cosmogenic nuclide dating (Balco et al, 2002;Balco and Schaefer, 2006;Bierman et al, 2015;Bromley et al, 2015;Davis et al, 2015;Corbett et al, 2017;Koester et al, 2017;Hall et al, 2017;Fig. 4).…”