By Kimberly Burkard

There is a story of an immense and terrible Great Serpent that not only threatened the people, it devoured them. A young boy and girl stood together against this terrifying beast. Where many others had failed, they succeeded in killing this Great Serpent. In its agonizing, thrashing death throes, this monster disgorged the skulls of its victims. These skulls rolled into the surrounding hills and waters while the body of the serpent sank into the dark depths of Canandaigua Lake.

This story is said to be Seneca, but there are questions about the details and origins of the various versions of this story. This article will not address those questions but there are sources listed at the end of the article that will aid any wishing to do further research. This article will focus on the geologic oddities that are often connected to this story, turtle stones.

To geologists, turtle stones are septarian nodules. Septarian nodules are a specific type of stone called a concretion. A concretion is essentially a mineral-laded mud that long ago collected together and turned to rock - a natural "cement," if you will. In the case of septarian nodules, the concreted stone has many angular cracks throughout it in which crystals have formed. Some of the most beautiful are sliced and polished to form bookends and curios. Turtle stones are generally oval in shape and the yellowish calcite that formed in the cracks has oozed out between the grey rock material to make the markings look like the back of a turtle.

These stones are more resistant to weathering than the host rock in which they are embedded and so they will often wash out to be found along streambeds and lakes. Because of their appearance, these stones are also called pseudofossils. They may look like fossils but actually have inorganic, non-fossil origins. To be clear, they are not fossilized turtle shells or dinosaur eggs though they have been mistakenly marketed as such!

Turtle stones can be found throughout the area. This summer my children and I found some nice ones in hikes along streambeds in Canandaigua. During a day-camp hike, my kids found some truly spectacular ones that someone had previously broken open. These stones were filled with small, dusky crystals and the specialness of them captured my children's imaginations. Imagination runs strong in our house. We have uncracked geodes sitting on a warm, sunny windowsill in hopes that dragons will hatch so you can imagine how truly special finding something like this for themselves was! (See the gallery below for more pictures.)

Like to see and touch a turtle stone yourself? There are a number of turtle stones located in and around our Visitors Center so be sure to look for them on your next visit to the Ganondagan State Historic Site. And while they are behind glass, the Rochester Museum & Science Center also has a couple on display in the Haudenosaunee displays that are not part of the "At the Western Door" exhibit. Be sure to look for them there as well.

I hope this has interested you enough to look down during some on your hikes. Who knows? Maybe a turtle stone will roll its way to your feet?

Gallery

Click on any of the images below for a closer look at the turtlestone.

One of the turtle stones at Ganondagan	Other turtle stones at the Visitors Center	Another stone at Ganondagan
Three stones at Ganondagan	The topside of a Ganondagan turtle stone	The underside of the stone to the left
Turtle stone at Onanda Park activities center	Turtle stone at the Rochester Museum & Science Center	Two more turtle stones at the RSMC
Turtle stone found in Canandaigua, NY	Turtle stone found in streambed	Not all are round
Some have subtle lines	Cross section of a turtle stone	Another cross-section
Detail of a turtle stone	Broken turtle stones full of crystals	Close-up of crystals in stone to the left

Sources

"Concretions" at www.rocksforkids.com/R&M/concretions.html

"Concretion" at en.wikipedia.org/wiki/Concretion

"Geode Vs. Septarians Concretions" at www.ehow.com/about_6709823_geodes-vs_-septarian-concretions.html

"History of Bare Hill Unit Management Area: Pre-European History" by G. Peter Jemison, on display at Bare Hill.

Iroquois Stories: Heroes and Heroines Monsters and Magic by Joseph Bruchac, The Crossing Press, Freedom, CA, 1985.

Legends and Stories of the Finger Lakes Region by Emerson Klees, Friends of the Finger Lakes Publishing, Rochester, NY, 1995.

"Legend of Bare Hill" by the Middlesex Heritage Group, on display at Bare Hill.

"Saint George, the Serpent and the Seneca Indians" by David D. Robinson, The Crooked Lake Review, Issue 71, February 1994. Available at: www.crookedlakereview.com/articles/67_100/71feb1994/71robinson.html

"Septarium" at stoneplus.cst.cmich.edu/septarium.htm