Site 2 Quarry Road Trails – Devil’s Chair Trail
Greetings Trail Users and Geology Fans!
Please note: Beware of poison ivy as you approach Devil’s Chair!
Here you are at Quarry Road. Every wonder where it got its name? At the top of the Devil’s Chair Trail you will be standing in front of it! Quarry Road Recreation Area got its name from a 19th century quarry at the site that earned the description “Devil’s Chair”. Stone obtained at the quarry here was used for local construction projects such as the original Central Maine Power generating station, the Memorial Hall buildings in Oakland and at Colby College, and the Pine Grove Cemetery Chapel in Waterville.
From 1880 to 1904 Maine was among the top five slate-producing states in the country, providing slate of excellent quality for roofing tiles and other purposes. The “Central Maine Slate Belt” extends approximately from Waterville to Brownville Junction. Many Maine homes and public buildings still bear their original slate tiles. Stone is a durable building material!
“Devil’s Chair” at Quarry Road Recreation Center, Waterville, September 2020
What’s Under Your Feet? Or in this Case, extending far above?
Does it surprise you that what’s under your feet is the same type of rock that makes up the imposing structure that you see before you.
According to Dr. Robert Marvinney, Maine State Geologist, the rocks that make up Devil’s Chair are metamorphosed sandstone and slate. They began as sediment in an ancient ocean. They are part of the Mayflower Hill Formation of Silurian age (between 419 and 444 million years old).
Picture what is now central Maine over 400 million years ago. It was part of a landmass that was much closer to the equator. Off the coast of this landmass to the east was a microcontinent known as Avalon. Beyond Avalon to the south and east were island arcs – a chain of small islands formed by volcanic activity. Between these islands and the coast, sediments were piling up on the seafloor and forming layers of sedimentary rock. Movements of the earth’s crustal plates caused Avalon and the mainland to collide.
The red dot represents the location of present day Maine
This was a slow process but a very powerful one, during which horizontal rock layers were compressed and folded, the ocean basin closed and the island arc became part of the larger land mass. Maine’s Coastline was added to in this way by a number of such events.
Note the vertical orientation of Devil’s Chair’s rocks. Recall that they were in a horizontal position at the bottom of an ancient sea bed when they first were deposited as sediments! IT’s clear that the rock formations that you see before you have been subjected to many powerful forces.
Forces that folded the rock layers also created enough heat and pressure to change the original sedimentary shale rock into slate – a harder more durable rock than it’s sedimentary predecessor. Slate has a microscopic fabric, or grain, called “slaty cleavage” which allows it to be split into large sheets for flagstones or roofing. You can see evidence of this in the slabs that have cleaved from the stone walls and fallen to the ground. These features – durability and the cleavage pattern are what made this rock material so useful much later on for human building projects.
