Borderland State Park offers the visitor a unique opportunity to see many interesting geologic features all within a short walk of the Visitors Center.

Perched boulders on a ledge at Borderland

The first feature is the glacial boulder walls in front of the Visitors Center. The rounded boulders were left 15,000 years ago by the last ice age. The granite bedrock under Borderland is 441 million years old (young when compared to the age of the earth, 450,000 million years old). The park has large glacially transported boulders weighing over a million pounds. Many other large perched boulders have been left all by themselves on ledges as if by some unseen giant setting them in a straight line. Large ledges with deep glacial grooves offer the visitor a chance to see the power of the glacial movement over the landscape thousands of years ago.

An fine example of a kettle pond and how it was formed can be seen near Leach Pond which was a post glacial lake then a swamp and then a Colonial-era man made pond. Upper Leach Pond is an excellent example of lake eutrification with the formation of floating bogs, which contain carnivorous plants. The large quantity of iron that is dissolved from the bedrock in the Park has allowed the formation of limonite deposits in the pond sediments. They are formed when bacteria use the iron to make their skeletons and the discarded skeletons build up in the pond sediments. Look for them at the stream flowing from Upper Leach Pond into Leach Pond: they appear as rust in the stream.

Limonite deposits make the water appear rusty

The fact that Borderland's terrain has considerable relief allows a wide variety of plants and animals to exist in within the Park. The well drained soils of the uplands support oaks, pines, red cedar and beeches, while the low wetlands support eastern white cedar, sweet pepper bush, red maples, and a large variety of wetland plants. Borderland sits on the watershed divide between the Taunton and Neponset Rivers, making most of the water free of manmade pollutants.

The park is home to some of the oldest plants, the lichens, which grow on the trees and rocks in abundance. Many lichens have been known to live thousands of years; they are also very good indicators of pollution and die when pollution is toxic (much as canaries were used to detect toxic fumes in mines). Borderland lichens are very healthy for now. Borderland is also the site of a quarry where the facing stone for the famous Canton Railroad Viaduct was cut 172 years ago. The stone is a fine grain Riebeckite Granite that was chosen because it does not stain as it weathers but retains its original color.