Penny ice cap cores, Baffin Island, Canada, and the Wisconsinan Foxe Dome connection: two states of Hudson Bay ice cover

Ice cores from Penny Ice Cap, Baffin Island, Canada, provide continuous Holocene records of oxygen isotopic composition ([Delta.sup.18]O, proxy for temperature) and atmospheric impurities. A time scale was established with the use of altered seasonal variations, some volcanic horizons, and the age for the end of the Wisconsin ice age determined from the GRIP and GISP2 ice cores. There is pre-Holocene ice near the bed. The change in [Delta.sup.18]O since the last glacial maximum (LGM) is at least 12.5 per mil, compared with an expected value of 7 per mil, suggesting that LGM ice originated at the much higher elevations of the then existing Foxe Dome and Foxe Ridge of the Laurentide Ice Sheet. The LGM [Delta.sup.18]O values suggest thick ice frozen to the bed of Hudson Bay.
The Penny Ice Cap on Cumberland Peninsula, Baffin Island, is the southernmost major ice cap in Canada. During the Wisconsin Ice Age, the ice cap was connected to Foxe Dome(1, [...]