Lake Merrimack facts for kids

Proglacial and prehistoric lakes of New England during the end of the Wisconsin Glacial Epoch of the Pleistocene Era. Based on map from 'Re-evaluation of Antevs' New England varve chronology and new radiocarbon dates of sediments from glacial Lake Hitchcock'; JOHN C. RIDGE and FREDERICK D. LARSEN

Lake Merrimack was a glacial lake that formed during the late Pleistocene epoch. After the Laurentide Ice Sheet retreated, glacial ice melt accumulated at the terminal moraine and blocked up the Merrimack River, creating the narrow lake. The lake extended from Manchester to Plymouth, New Hampshire. It is unknown when the lake was drained.

Lake Hitchcock is an important part of the geology of New Hampshire. It experienced annual layering of sediments, or varves: silt and sand in the summertime (due to glacial meltwater) and clay in the wintertime (as the lake froze).