Noted geologist George Holt has discovered a new record glacial boulder in Dunbarton and will lead a hike to it Saturday, Feb., 25.
Meet and park on the east side of Kimball Pond road at the entrance to the old town gravel pit. This is approx. 0.9 miles south of the Kimball Pond boat ramp and approx. 0.4 miles north of the intersection of Little Lane and Kimball Pond Road.
The hike will be approximately 1.5 miles round trip through the woods without the aid of a trail. Everybody will need snow shoes. Bring water, snacks and warm clothing.
The hike will start at 9 am. We should be out of the woods by 11 or 12.
The boulder's circumference measures approx. 95 feet, which translates to an average diameter of 30 feet. The maximum height is about 20 feet.
Using the a horizontal radius of 15 feet and a vertical radius of 10 feet, the approximate ellipsoidal volume is 4/3* pi*15*15*10, which is approximately 9,400 cubic feet.
Assuming that the granitic rock weighs approx. 175 pounds per cubic foot, the boulder weighs approx. 1.65 million pounds, or approx. 825 tons! Previously measured boulders in Dunbarton weighed in the range of 100 tons.
For more information: Conservation Commission member George Holt, george@naturofm.com.
