Regional stagnation of ice in northeastern Connecticut: An alternative model of deglaciation for part of New England

Abstract

Re-evaluation of published maps and reconnaissance of the rest of the Shetucket River basin lead to the conclusion that stagnation of the late Wisconsinan ice occurred simultaneously throughout the basin rather than in narrow zones during ice-margin recession as has been the accepted model for decades in New England. Evidence includes especially (1) ice-contact deposits laid down over large areas, from the highest hills to the valley bottoms, wherein ice to the south was required, and (2) a series of discontinuous ice-contact lake deposits extending tens of kilometres up all major valleys, which were graded to a major ice and drift barrier in the lower part of the basin. Neither of these situations is possible at the scale observed in ice-margin recession. Regional deglaciation suggests that previous estimates of the ground-water capacity of the valley fills and of the supply of coarse construction aggregates are too high.