In the master core (S-2009) basal sandy silt (till) is overlain by reddish-brown varved clay
(core depth 745-708 cm) in which 29 annual varves were identified (Fig.
Comments: The site is on a deep varved clay
deposit (Connecticut Valley Varved Clay
) on the University of Massachusetts, Amherst campus.
(2005) recorded an only 4.5 m thick varved clay
layer between the Warthanian (Late Saalian) till and the Eemian sediments in the Licze core in northern Poland.
Consequently, the formation of bottom deposits may have been influenced by currents and wave activity, but the erosion areas are located near the deposition area--inside the bay (till and varved clay
exposed on the seafloor) or on bordering peninsulas (bedrock).
Within 1.5 km north of the city boundary, 2-3 m thick lenses of varved clay
were found in the lower part of the sand layer.
Fine sand, silt, and varved clay
, typical of ice lakes, facilitated drawing up the contours of ancient lakes (Fig.
Proglacial varved clay
is outcropping in the northern part of the lake bottom.
In the southern part of the lake glaciolacustrine varved clay
was not distinguished within the corings (Fig.
The lowermost unit A consists of brownish-grey proglacial varved clay
which lies on top of Late Weichselian till.
Laminated clayey deposits (Photo 1E) or brecciated varved clay
inclusions and coarse-clastic diamicton lenses are found in this depositional unit.
Studies of varved clays
in West Virginia by Janssen and McCoy (1953) placed the minimum duration of Lake Tight at 6,500 years.
Van Asch, "Factors controlling the movement of a landslide in varved clays
near La Mure (French Alps)," Bulletin de la Societe Geologique de France, vol.