Time of Maximum Late Wisconsin Glaciation, West Coast of Canada

Marine records indicate that ice reached the edge of the continental shelf at its last maximum and formed an extensive margin across Queen Charlotte Sound.

“Marine records indicate that ice reached the edge of the continental shelf at its last maximum and formed an extensive margin across Queen Charlotte Sound (Barrie & Conway, 1999, 2002a;Blaise et al., 1990;Davies et al., 2011;Luternauer, Clague, et al., 1989;Luternauer, Conway, et al., 1989).”

Minimum limiting radiocarbon ages from Haida Gwaii indicate that ice decay was underway by 19.4 ka.

“In contrast, minimum limiting radiocarbon ages from Haida Gwaii on the central west coast (Figure 1) have been interpreted to indicate that ice decay was underway by 19.4 ka (Blaise et al., 1990;Clague et al., 1982;Mathewes & Clague, 2017;Warner et al., 1982).”

Calving of marine-terminating sections of the ice margin likely accounts for large increases in ice-rafted debris at 17.7-18.5 ka in marine core PAR85-01 off Queen Charlotte Sound.

“Calving of marine-terminating sections of the ice margin likely accounts for large increases in ice-rafted debris at 17.7-18.5ka in marine core PAR85-01 off Queen Charlotte Sound (Blaise et al., 1990).”

The western edge of the Cordilleran Ice Sheet advanced across Hecate Strait at ca. 30.0 ka and reached Haida Gwaii after ca. 22.0 ka, but was retreating by ca. 19.4 ka.

“The timing of deglaciation reported here agrees with findings from north of the study area (Blaise et al., 1990;Clague et al., 1982;Mathewes & Clague, 2017;Warner et al., 1982), implying that the western edge of the Cordilleran Ice Sheet advanced across Hecate Strait at ca. 30.0 ka and reached Haida Gwaii after ca.22.0 ka, but was retreating by ca.19.4 ka (Figure 4i).”