Northeastern Section - 42nd Annual Meeting (12–14 March 2007)

Paper No. 7
Presentation Time: 1:00 PM-4:45 PM


BROOKS, John A. and TINKHAM, Daniel J., Emery & Garrett Groundwater, Inc, PO Box 1578, 56 Main Street, Meredith, NH 03253,

Detailed surficial mapping (1:24,000 scale) of six 7.5-minute quadrangles within the Lakes Region of New Hampshire (Goldsmith, R., 1992, Alton; Hildreth, C.T. and Nelson, A.E, 1998, Belmont; Brooks and Tinkham, 2002, Laconia; Nelson, A.E. and Nelson, J., 2002, Winnisquam Lake; Tinkham and Brooks, 2003, Northfield; Tinkham and Brooks, 2004, West Alton) has provided the opportunity for investigating the regional deglaciation of the Lakes Region area of New Hampshire. A compilation of these surficial maps is presented to highlight the style and timing of deglaciation west of Lake Winnipesaukee.

The glacial history of the region west of Lake Winnipesaukee includes the:

1) Development of multiple glacial lakes in northward facing valleys in the regions of Laconia, Gilford, and Northfield; 2) Melting of the ice sheet northward from the Farmington area and the creation of the incipient Lake Winnipesaukee (Glacial Lake New Durham); 3) Transition from regional glacial melt water flow southward to the Cocheco River watershed to a westward flow into the Winnipesaukee River watershed; 4) Deposition of ice contact, glaciofluvial, and glaciolacustrine deposits in the Tilton, Laconia, and Northfield areas; and 5) Lake Merrimack glaciolacustrine deposits, and dune deposits later formed from Lake Merrimack deposits, are mapped in the western portion of the Northfield Quadrangle.