Glacial Lake Hitchcock and the sea: Fieldtrip Guidebook for the 78th Annual Reunion of the Northeast Friends of the Pleistocene

The fieldtrip will demonstrate the evidence for a close connection of Lake Hitchcock levels
with lake levels and the position of sea level in Long Island Sound via a channel cut into glacial
lake deposits in the lower Connecticut River valley, which issuperposed on a bedrock ridge at
the mouth of the Connecticut River. On the trip we will explain important offshore features like
an extensive  ‐40‐m marine delta, and the altitudes of “The Race” spillway cut through the
Harbor Hill moraine, Block Channel spillway cut through the terminal moraine, and the  ‐85‐m
Block Delta built into Last Glacial Maximum (LGM) eustatic sea level 115 km south of the
terminal moraine. The history of lake levels and knowledge of eustatic sea levels provided by the
Barbadossea level curve (Bard and others, 1990) have implications for the magnitude of glacio‐
isostatic depression and the timing of rebound.  We will also review recent refinements to
the chronology of ice retreat through the region as a result of new varve cores and the newly
calibrated North American Varve Chronology (NAVC) (Ridge, 2004, Ridge and others, 2012)
and discuss implications for the timing and mechanism of glacial Lake Hitchcock drainage in
Connecticut.