02901nas a2200229   4500008004100000022001300041245009300054210006900147260002100216300001200237490000800249520220800257653001602465653001402481653001402495653001202509653001902521100002102540700002202561700002202583856006602605       2018                        eng d  a0169555X00aLaurentide ice sheet meltwater routing along the Iro-Mohawk River, eastern New York, USA0 aLaurentide ice sheet meltwater routing along the IroMohawk River  cDecember 5, 2017  a155-1610 v3033 a<p id="sp0040">The rerouting of meltwater as the configuration of ice sheets evolved during the last deglaciation is thought to have led to some of the most significant perturbations to the climate system in the late Quaternary. However, the complex pattern of ice sheet meltwater drainage off the continents, and the timing of rerouting events, remains to be fully resolved. As the Laurentide Ice Sheet (LIS) retreated north of the Adirondack Uplands of northeastern New York State during the last deglaciation, a large proglacial lake, Lake Iroquois, found a lower outlet that resulted in a significant flood event. This meltwater rerouting event, from outflow via the Iro-Mohawk River valley (southern Adirondack Mountains) to the spillway at Covey Hill (northeastern Adirondack Mountains), is hypothesized to have taken place ~&nbsp;13.2&nbsp;ka and disturbed meridional circulation in the North Atlantic Ocean. However, the timing of the rerouting event is not certain because the event has not been directly dated. With improving the history of Lake Iroquois drainage in mind, we obtained cosmogenic <sup>10</sup>Be exposure ages on a strath terrace on Moss Island, along the Iro-Mohawk River spillway. We hypothesize that Moss Island's strath terrace became abandoned during the rerouting event. Six <sup>10</sup>Be ages from the strath surface average 14.8&nbsp;±&nbsp;1.3&nbsp;ka, which predates the previously published bracketing radiocarbon ages of ~&nbsp;13.2&nbsp;ka. Several possibilities for the discrepancy exist: (1) the <sup>10</sup>Be age accurately represents the timing of a decrease in discharge through the Iro-Mohawk River spillway; (2) the age is influenced by inheritance. The <sup>10</sup>Be ages from glacially sculpted surfaces on Moss Island above the strath terrace predate the deglaciation of the site by 5 to 35&nbsp;ky; and (3) the abandonment of the Moss Island strath terrace relates to knickpoint migration and not the final abandonment of the Iro-Mohawk River as the Lake Iroquois spillway. Further study and application of cosmogenic <sup>10</sup>Be exposure dating in the region may lead to tighter chronologic constraints of meltwater history of the LIS.</p>
10a10Be dating10aIce sheet10ameltwater10aPothole10aStrath terrace1 aPorreca, Charles1 aBriner, Jason, P.1 aKozlowski, A., L.  uhttp://linkinghub.elsevier.com/retrieve/pii/S0169555X17305056