 The directions of tilting of the three shorelines (in the quadrant between north and east), are at variance with published glacio-isostatic uplift isobases based on marine shoreline data that suggest a pattern of decreased uplift towards the northwest.The gradient of shoreline tilting (between 0.11 and 0.14 m/km) is similar to measured regional tilts of a well-developed marine shoreline (the Main Rock Platform) considered to have been produced in Scotland during the same period of extreme cold climate.Consideration of the ice-dammed lake shoreline data also points to the former occurrence of two separate episodes of tectonic activity during the Younger Dryas (Greenland Stadial 1 - GS1).