I recently went to Turners Falls, MA to find some unusual fish fossils. Sadly, I did not find them, as I misread where to find them and looked in the wrong place. However, as a consolation prize, I did check out another unusual geologic feature found there – armored mud balls.
Turns out, they are an incredibly rare, and often overlooked geologic feature, there are only about 10 locations in the world where they are found, one of which is in the towns of Turner’s Falls and Greenfield in the Connecticut Valley of northwestern Massachusetts.† .Also, of the few armored mud balls, these one are unique, in that they are the only known specimens to have formed in lakes.††
Now what exactly is an armored mud ball? Good Question. They are round balls of mud that have rolled down hills and into an aquatic environment collecting pebbles along the surface, the pebbles are it’s armor.†† These have then been buried and preserved.† In the images above, you can see the within the sandstone rock, the darker colored mud balls, and the pebbles that surround them. These particular armored mud are approximately 200 million years old and from the early Jurassic Period.†† Also they are found in the remains of an old bridge – all that is left are a few stone supports – in Unity Park in the village of Turner’s Falls,†† as I mentioned earlier can be found elsewhere in the area.†
So, if in Turner’s Falls, check them out along with other geologic features, a cool bike trail, and some bald eagles (which I saw, but was unable to take a picture)
†Skehan, James W. “Roadside Geology of Massachusetts” pgs 256-7. 2001 Mountain Press Publishing Company
†† Winters, Steve “A Geologic Walking Tour of Turners Falls Massachusetts” pg 12-3. 2011 Turners Falls RiverCulture Project (pamphlet available at Great Falls Discovery Center in Turners Falls, also https://jurassicroadshow.files.wordpress.com/2013/03/geologic-walking-tour-of-turners-falls-ma2.pdf )