Research Request
We're looking for geological sediments of Lake Hitchcock. The
lake was one of the largest of the glacial lakes in New England.
It stretched from New Britain, Connecticut, just south of
Hartford, north to St. Johnsbury in northern Vermont, ca. 175
miles. The lake was the result of ice-stratified deposits at
Rocky Hill, Connecticut that dammed the ice melt as the last
glacier retreated northward. The inception of the lake in
central Connecticut is placed at 15,600 yrs BP, with the initial
breaching of the Rocky Hill dam 12,300-12,400 yrs BP and the
final drainage of the lake soon after. The Connecticut River
generally follows the course of Lake Hitchcock and, in many
places, the river has eroded into and sometimes through the
lake-bottom sediments. Diving in these portions of the river is,
in many respects, like going back in time and exploring the
bottom of Lake Hitchcock. The lake's sedimentary layers are
known as varves, each is a couplet of a whitish-gray clay layer
and a yellowish-brown silty/sandy layer; a couplet represents a
single year, the silty/sand deposited in the summer during ice
melt and the clay layer deposited in the winter when the lake was
frozen.
Have You Seen Varves?
Photo
1: Varves in cross-section, note alternating clay and sandy
layers; knife haft = 10cm
Photo
2: Clay surfaces of varves
Researchers at the University of Massachusetts are interested in
locating underwater varve sites in the Connecticut River and its
tributaries. If you have seen anything that resembles these
pictures, please contact Ed
Klekowski. You will be acknowledged in scientific
publications based upon research at your sites. You will even be
asked to guide us to your site (free air refills next summer!).
