Deglaciation, basin formation and post-glacial climate change from a regional network of sediment core sites in Ohio and eastern Indiana

Abstract

Many paleoclimate and landscape change studies in the American Midwest have focused on the Late Glacial and early Holocene time periods (~ 16–11 ka), but little work has addressed landscape change in this area between the Last Glacial Maximum and the Late Glacial (~ 22–16 ka). Sediment cores were collected from 29 new lake and bog sites in Ohio and Indiana to address this gap. The basal radiocarbon dates from these cores show that initial ice retreat from the maximal last-glacial ice extent occurred by 22 ka, and numerous sites that are ~ 100 km inside this limit were exposed by 18.9 ka. Post-glacial environmental changes were identified as stratigraphic or biologic changes in select cores. The strongest signal occurs between 18.5 and 14.6 ka. These Midwestern events correspond with evidence to the northeast, suggesting that initial deglaciation of the ice sheet, and ensuing environmental changes, were episodic and rapid. Significantly, these changes predate the onset of the Bølling postglacial warming (14.8 ka) as recorded by the Greenland ice cores. Thus, deglaciation and landscape change around the southern margins of the Laurentide Ice Sheet happened ~ 7 ka before postglacial changes were felt in central Greenland.

Neutron activation analysis of 12,900-year-old stone artifacts confirms 450–510+ km Clovis tool-stone acquisition at Paleo Crossing (33ME274), northeast Ohio, U.S.A.

“…(ca. 15,000 calBP) (Gill et al, 2012;Glover et al, 2011;Herdendorf, 2013;Hill, 2006;Metcalfe et al, 2013;Szabo and Chanda, 2004;Yu, 2000). After which these foragers could have procured stone from outcrops located closer to Paleo Crossing either during their journey to the site or through exchange or logistical forays after establishing a camp at Paleo Crossing.…”

Southern Laurentide ice-sheet retreat synchronous with rising boreal summer insolation

“…A 14 C date from post-glacial lakes in Ohio suggest ~100 km of Miami-Scioto lobe retreat prior to 19.5 ± 0.2 ka (AA-45079, Table DR2) ( Fig. 2F) (Glover et al, 2011). Later readvances by the Green Bay, Lake Michigan, and Miami-Scioto lobes are evidenced by detailed stratigraphy and chronological constraints (Mickelson et al, 1983); however, none of these re-advances reached the LGM moraines.…”

“…To the east, the Miami-Scioto lobes began retreat northward from LGM positions in southern Indiana-Ohio before 22.4 ± 0.2 ka (Beta-72287, Table DR2), according to the oldest minimum-limiting 14 C date from within the terminal moraine in southern Ohio (Glover et al, 2011) (Fig. 2F).…”

“…1B) (Mickelson et al, 1983). The chronology of many of the southern LIS lobes is established by minimum-and maximum-limiting 14 C dates on boreal forest wood that bracket the initial timing of retreat (Clayton and Moran, 1982;Mickelson et al, 1983;Hansel and Johnson, 1992;Clark et al, 2009;Curry and Petras, 2011;Glover et al, 2011), but the presence of permafrost along the margins of LIS lobes in Wisconsin (USA) has limited the application of 14 C dating in determining when ice retreated (Clayton et al, 2001). Alternative efforts at constraining the timing of LIS retreat in Wisconsin have employed bedrock 10 Be exposure ages and optically stimulated luminescence (OSL) ages on proglacial lake deposits (e.g., Colgan et al, 2002;Carson et al, 2012), but large uncertainties could indicate a significant delay in ice retreat in Wisconsin relative to other southern LIS margins.…”

Stratigraphic and chronologic analysis of the Warren Beach, northwest Ohio, USA

“…After the Port Bruce Stadial, the Huron-Erie lobe began receding at ϳ15 500 14 C years BP (ϳ18 700 cal years BP) from the Union City -Powell Moraine in northeast Indiana (Barnett 1985;Calkin and Feenstra 1985;Glover et al 2011). Once ice receded from the Fort Wayne Moraine, Lake Maumee began forming in lower topography dammed by the receding ice mass and the higher topography to the west, draining through the Fort Wayne outlet (Fig.…”