Earth Day Owl Program



GMF celebrated a cold and blustery Earth Day with a presentation about owls by Mary-Beth Kaeser, director of Horizon Wings Raptor Rehabilitation and Education in Ashford. She and two volunteers shared their extensive knowledge with a close view of five beautiful owls: the northern saw-whet, eastern screech, barred, barn and great-horned owls. The audience experienced calls, observed owl behavior, and learned about conservation as well as the protocol for injured birds found in the wild.

The geological underpinnings of Northwestern Connecticut determine the conditions for the above-ground forest seen at GMF today. Although the underlying bedrock is obscured by soil and vegetation in many landscapes, at GMF exposed outcrops are a common feature permitting easy recognition of different rock types. These types can be categorized as igneous (volcanic in origin), sedimentary (coalesced deposited material) and metamorphic (starting as igneous or sedimentary but changed by heat and pressure to a recrystallized mineral makeup). GMF has all three, including igneous granite, sedimentary limestone, and a range of metamorphic rocks, including gneiss that starts as granite, schist from slate and marble from limestone.

         Plate tectonics and erosion over the millennia ensured that these rock types did not stay neatly stacked. The word “orogeny” comes from combining the Greek words for “mountain” and “creation.” Over a billion years ago, the Grenville Orogeny formed the bedrock defining the Western Upland terrane for this region. By four hundred million years ago, Great Mountain Forest was beachfront property on the Iapetos Ocean. Later continental fender benders thrust marine rocks into already existing layers, forcing older formations atop younger ones. This includes Canaan Mountain Schist, the dominant rock found in GMF, with exposed outcrops on the Matterhorn, Stoneman, and Blackberry Hill. Also present is the marble of the Stockbridge Formation, found around Tobey Pond and the Chestnut Orchard, while boulders from it compose the talus slope above the orchard.

These formations affect what grows at the surface. Schist is a felsic metamorphic rock, i.e., composed of mica and quartz, leading to less fertile and more acidic soils. However, plant species such as blueberries, azaleas, rhododendrons, mountain laurels and sourwoods have evolved to survive, and even prefer, these soils with a pH of around 5. On the other hand, the marbles found primarily in the valleys of Canaan and Norfolk are rich in calcium carbonate, creating rich and well-drained soils for forests and agriculture.