Purgatory Chasm Rocks

While offering heavenly views, Purgatory Chasm can be hell on your ankles.

So it's probably a good idea to let sure-footed Sheryl Farnam lead you this Sunday, May 18, 2008, through the strangest geological mystery in central Massachusetts.

A natural history guide for the Massachusetts Audubon Society, the Grafton resident will lead a two-hour tour through the rugged quarter-mile granite fissure in Purgatory Chasm State Reservation.

Starting at 2 p.m., Farnam will discuss theories about the chasm's geologic origins, unusual rock formations and folklore about the site.

Visitors will get to see rock formations with curious nicknames like Corn Crib, The Devil's Coffin, The Pulpit, His Majesty's Cave and Fat Man's Misery, a path too narrow for most members of "The Biggest Loser."

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Stationed at Broad Meadow Brook Wildlife Sanctuary, Farnam will lead visitors to Lover's Leap, which supposedly took its name from the tale of an ill-fated woman who years ago jumped 75 feet to her death from the cliff top for unknown reasons.

More recently, several hikers have been injured and some deaths reported.

In 2002, a 21-year-old student from the Rhode Island School of Design accidentally fell to her death while hiking with friends near Lover's Leap.

But rather than focusing on broken hearts, Farnam plans to conduct a "stop-and-talk" tour to discuss the features of the granite and gneiss rift geologists believe was formed 14,000 to 15,000 years ago.

Farnam strongly suggests tour members leave their sandals at home and wear sturdy "lace-up" footwear with good traction since the rocks can be slippery. She recommends not bringing children younger than 8 into the chasm because they may slip, posing safety problems for parents or other group members.

While there is no upper age limit for the tour, she pointed out there are several precarious sections that could result in falls or sprained ankles. "You really have to be pretty sure-footed," she said. And she suggests bringing a water bottle, especially on a hot day.

While the origin of the chasm's name has been lost to history, Farnam believes early Quaker settlers might have bestowed the name Purgatory to suggest the eerie-looking jumble of rocks was "halfway between heaven and hell."

More recently Susan Edwards Richmond, poet in residence at Fruitlands Museum in Harvard, published in 2007 a chapbook of poetry titled "Purgatory Chasm" that explores the site's geologic and human history in sharp, precise images.

At the beginning of each tour, Farnan introduces several theories about the chasm's geologic origins, which she later rebuts.

While amateur scientists once attributed the chasm to a volcanic eruption, she pointed out the rocks' jagged surface would have been melted smooth if that was the cause. She also rejects an earlier theory rushing water in prehistoric times caused the fissure because the same torrent would have polished the rocks' surface far smoother than they now appear.

Farnam accepts the theory proposed by professor Mauri Pelto, who teaches geology at Nichols College. He maintains the chasm was a "fault plane" in which gigantic slabs of facing rock ground against each other in ancient times, leaving still visible grooves.

He attributes the chasm's formation to "the plucking action of a glacier moving over a pre-existing crack in the rock caused by faulting." While the area was once covered by a mile-high glacier, Pelto doubts the rift was caused by a ice pushing through it but speculates water dripped from it, and then refroze, to carry rocks away giving it its irregular shape.

At first glance, Purgatory Chasm resembles a fantastic realm populated by giants and trolls that might have been sprung from J.R.R. Tolkien's imagination.

But on a warm Tuesday afternoon, the only dangerous creatures were swarms of carnivorous blackflies zooming in to snack on sweating hikers.

They didn't seem to bother 12-year-old Dan Sullivan and Andy Myers of Whitinsville who clamored up a granite slab like a pair of mountain goats. "It's great," said the nimble Sullivan. "It's fun and easy to climb. I just go in and up and out."

Take the advice of a pear-shaped middle-aged reporter: Bring good footwear and enjoy Purgatory Chasm at your leisure.

THE ESSENTIALS:

Purgatory Chasm is located in Purgatory Chasm State Reservation off Rte. 146 in Sutton. Admission is free. Go to http://www.mass.gov/dcr/parks/central/purg.htm for more information about the park, or call  508-234-3733.

The Department of Conservation and Recreation, which manages the 900-acre reservation, requires a permit for rock climbing in the chasm.

Sheryl Farnam will lead a tour of Purgatory Chasm Sunday, May 18, at 2 p.m., not 1 p.m. as listed in the Audubon Society catalog.

Fees for the tour are: adults, $6 for Audubon Society members and $8 for nonmembers; $4 for children of members and $6 for the children of nonmembers.

The Sunday afternoon tour is limited to 20 people. For reservations, call  508-753-6087. Farnam will also lead the tour on Saturday, Aug. 9, at 10 a.m.

Other events

The Mass Audubon Society is holding a Bird-a-Thon Friday and Saturday, May 16 and 17, at Broad Meadow Brook Sanctuary in Worcester and Wachusett Meadow Wildlife Sanctuary in Princeton.

The events include free guided evening tours from 6 to 8 at both sanctuaries. On Saturday, students in the West Boylston Biodiversity Club will lead a 10 a.m. walk at Wachusett Meadow. Mass Audubon naturalists will lead one-hour hikes at both sanctuaries at 11 a.m. and 4 p.m.

Enjoy "Birds and Breakfast" at both sanctuaries Saturday from 7 to 10:30 a.m. Fees: adult members $10 and nonmembers $14; children, members $5 and nonmembers $7.

For information and to register, call Wachusett Meadow at 978-464-2712 or Broad Meadow Brook at 508-753-6087.

To learn more about Nichols College professor Mauri Pelto's theory about Purgatory Chasm, visit www.nichols/edu/departments/purgatorychasm/.