There are many interesting topics besides wine that I like to explore in the Finger Lakes, one of which is geology. Here is a short primer on the geology of the Finger Lakes to give you something to think about when visiting the area and traveling from winery to winery.
There are eleven Finger Lakes in New York State. They are called Finger Lakes because they are long, narrow bodies of water that reminded early map makers of the fingers on a hand . The lakes generally run north to south and are all located south of the New York State thruway. The western most lake (Conesus) is located south west of Rochester and the eastern most lake (Otisco Lake) is located south west of Syracuse. In between these lakes, listed from west to east, are Hemlock Lake, Canadice Lake, Honeoye Lake, Canandaigua Lake, Keuka Lake, Seneca Lake, Cayuga Lake, Owasco Lake, and Skaneateles Lake.
The lake valleys were formed by several glaciers that advanced and retreated through the area over the last two million years . Ancient rivers flowed from south to north through these valleys. As the last glacier to cover this area retreated over eleven thousand years ago, these rivers were dammed by sediment and glacial debris causing lakes to form. The Finger Lakes are the remains of these glacial lakes.
Along with the lakes, deep gorges were formed. Streams flow through these gorges, further eroding the earth and rock to deepen the gorges. The softer layers erode more quickly than the harder, more durable layers. Where the water meets these harder layers, waterfalls and cascades form. Ithaca, at the south end of Cayuga Lake, has perhaps the highest concentration of these waterfall laden gorges in the entire Finger Lakes region.
Cayuga Lake is the longest of the eleven Finger Lakes at 38.2 miles long . Seneca is the second longest (~35 miles long) and the deepest at 651 feet deep. Keuka Lake is forked with two branches at the north end of the lake. Hemlock and Canadice Lakes are the only two lakes that are uninhabited. These lakes serve as a major source of water for the city of Rochester.
The topology of the land surrounding Seneca, Cayuga, and Keuka Lakes, along with the thermal mass provided by the lakes themselves, makes these lake regions prime areas for growing grapes. The protective hills and warming waters moderate the climate relative to areas further from the lakes which is an advantage for grape production.
There are many other geological features in the region that are a result of glacial activity. To learn more I suggest reading “The Finger Lakes Region. Its Origin and Nature” by O. D. von Engeln, Cornell University press or refer to one of many resources on the web, including the citations noted below.