Come discover the story behind Lynnfield’s glacial erratic — a boulder carried and left behind by glaciers thousands of years ago!
The program will take place on Nov. 15 from 10 a.m. to noon, with a rain date scheduled for Nov. 16 from 10 a.m. to noon. The event will begin at Lynnfield Woodlot at 1452 Main St., Lynnfield.
Event highlights include a scenic 2-mile round-trip walk, which could last approximately two hours. Event-goers will learn about glacial geology and local ecosystems. Sturdy, waterproof walking shoes, water bottles, and weather-appropriate clothing should be brought.
Signups are online on the Town of Lynnfield website.
Join Nick Federico for a guided walk to Lynnfield’s Glacial Erratic. Nick is a resident of Lynnfield and a member of the Open Space & Recreation Work Group. Nick’s volunteer work in Lynnfield’s conservation areas includes clearing the entrance to the Beaver Dam Brook Reservation and Gerry’s Cider Mill Park, in addition to repairing the Partridge Island Boardwalk. He has a Bachelor of Science degree in Geology and currently works as a Geologist at an environmental consulting company on the North Shore.
What is a Glacial Erratic?
- A glacial erratic is a rock or boulder that has been transported by a glacier from its original bedrock and deposited elsewhere.
- They are a testament to the immense power of glaciers, which can pick up and move enormous blocks of rock over great distances.
- Geologists can identify a glacial erratic when its composition is dissimilar to the local bedrock but similar to the bedrock found in a location to the north
Where are the Glacial Erratics near Lynnfield?
- Lynn Woods/Breakheart Reservation (Geology on Foot, Lynn/Saugus)
- Giant erratic (Harold Parker State Forest, Andover): A large erratic that is reportedly falling apart due to frost.
- The Monolith (thetrustees.org/place/the-monoliths/, Manchester-by-the-Sea): The Big and Little Rocks are dramatic examples of giant boulders plucked from bedrock and carried far away by the last glacier.
Where is the largest in the North Atlantic?
- The largest glacial erratic in North America is the Madison Boulder in Madison, NH, which is a granite boulder measuring approximately 83 feet long, 37 feet wide, and 23 feet high.
- Other notable examples near you include the Daggett Rock in Maine, which is considered the state’s largest, and Bubble Rock in Acadia National Park.
These rocks are called glacial erratics because they were transported and deposited by glaciers from a different bedrock location.
Where are large fields of glacial erratics?
- Puget Sound Region, Washington: This area has many glacial erratics strewn across the lowland from Canadian rocks.
- Yellowstone National Park, Wyoming: Glacial erratics can be found throughout the park, including a large one near Inspiration Point.
- Ethiopia: Researchers have identified numerous erratics in the Bale Mountains, deposited more than 28,000 years ago.
- North Dakota: Erratics are common along the shores of modern lakes, such as Devils Lake.
