This image shows glacial varves from the Connecticut Valley at the southern end of Lake Hitchcock near Hartford, Connecticut. The winter (W) or non-melt season layers (dark, top part of each annual layer) contrast with the light-colored summer (S) layers. These varves were deposited at least 350 years after ice recession at the site, when the receding ice margin was 45 km to the north near Holyoke, Massachusetts. Sedimentation was still dominantly controlled by the input of sediment from the receding glacier, but with significant contributions from rivers that no longer carried glacial meltwater. Image and caption courtesy of Ridge, J.C., 2008, “The North American Glacial Varve Project”: (http://ase.tufts.edu/geology/varves), sponsored by The National Science Foundation and The Geology Department of Tufts University, Medford, Massachusetts.
Originally uploaded in Cutting Edge:Topics:Climate Change:Workshop 2010.
Image 19837 is a 367 by 250 pixel JPEG
Uploaded: Feb10 10