Lake Varves and Radiocarbon Dating

Lake varves are distinctive annual layers of deposits found in lakes. Although other layers, "laminae', occur resulting from such things as storms, varves are distinct in that they each contain a succession of pollen types, reflecting the succession of plants that produce pollen through the growing season. They also show a succession of grain sizes in the silt laid down, because only in winters does the finest silt settle on the lake bottom.

Lake varve counts (not counting fossilized varve deposits) have been made up to around 60,000 years.

Radiocarbon dating is based on the known half-life of carbon 14.

When varves are dated using radiocarbon dating, the results agree with the date obtained by the varve count.

Varve deposits and carbon 14 decay are completely independent phenomena. If there was any problem with either (or both) of these measures, they would not agree to the degree that they do.