By Sam Nunes, Environmental Educator,
For this month I would like to take you back in time thousands of years, when Connecticut was so cold there was a mile of ice on top of it.
Back in the last Ice Age, which ended about 12,000 years ago, Connecticut was covered by the glaciers that spanned over most of northern North America. Those glaciers danced and slid across our landscape to carve our hills and valleys,. They’re even responsible for the creation of Long Island.
Not only did these glaciers form the large features of our landscapes, they also tore off chunks of rocks to make smaller stones. Over time, these rocks were buried by sediment and soil.
Fast forward to when farming accelerated in Connecticut during Colonial times. While tilling and loosening the soil to plant seeds, farmers uncovered the stones. There were too many stones to pile, so the farmers formed them into lines. Pretty soon those lines were long enough to form walls. This continued year after year as continuous tilling and rain eroded away the soil and revealed more stones. The farmers started to believe that the devil was putting the stones in the ground to challenge them, leading to the stones being called the Devil’s Potatoes.
Today you may find miles of stone walls sectioning off parts of the forest along trails here in Connecticut. It is estimated that we have over 100,000 miles of stone walls in New England. That’s enough to circle the earth four times! We even have many right here at Woodcock Nature Center.
A fun activity to do with stone walls is to calculate their age by measuring the radius of lichen on the stones. Lichen is a symbiotic relationship between a fungus and a plant that grows very slowly on the surface of objects that don’t move. To calculate the age of a stone wall, find the largest lichen circles (choose distinct, separate circles, not blob-shaped lichens formed by several circles growing together) and measure the radius in centimeters. Lichen grows approximately 1 centimeter every 10 years. Multiple the radius by 10 to find out how old the lichen is. There are many variables that can affect the lichen growth so be sure to measure several and average them.
How old are the stone walls near you?