Geology and Ecosystem
Mount Toby is considered one of the most biodiverse areas in New England. Fern and orchid species are particularly prolific on the mountain; forty-two of forty-five possible native fern species grow there as do rare orchids such as the Showy Lady Slipper and the Ram’s Head Lady Slipper. Unlike the surrounding region, Mount Toby was never cleared of its timber during New England’s intensive agricultural period in the 18th and 19th centuries; it has remained wooded throughout, although timber harvesting has played a part in its history.
Geologically speaking, Mount Toby is composed of a sedimentary conglomerate base known as Mount Toby Conglomerate. It is associated with the geologic processes which created the Metacomet Ridge that extends through New England from Long Island Sound to the Vermont border. Mount Toby is part of a larger geologic layer cake. The bottom layer is composed of arkose sandstone, visible across the Connecticut River on Sugarloaf Mountain in Deerfield, Massachusetts. The middle layer is composed basalt; it is most visible as the geology of the Pocumtuck Ridge, to the north. The top (youngest) layer is composed of Mount Toby Conglomerate. About 200 million years ago, as the continent of North America began rifting apart from Africa and Eurasia, a series of erosion and deposition episodes interspersed with heavy basalt lava flows created this layer cake. Faulting and earthquakes tilted the layers diagonally; subsequent erosion and glacial activity exposed the tilted "layers" of sandstone, basalt, and erosion-resistant conglomerate visible today. Although not composed of trap rock, Mount Toby is a closely associated with the trap rock Metacomet Ridge by virtue of its origin via the same rifting and uplift that created those mountains.
Mount Toby like many of the hills and mountains of New England was formed by volcanism.
The west and south sides of Mount Toby drain via a series of brooks into Connecticut River, thence Long Island Sound. The east side drains into Long Plain Brook, thence the Connecticut River. The north side drains into Cranberry Pond Brook, thence the Connecticut River.
Read more about this topic: Mount Toby