Rhode Island Formation Carboniferous Fossils
By Ophelia W. Ravenia
Sometimes I explore places that are “off the map”. That is to say, places that aren’t well known and that don’t have a digital presence– whether it’s an entry on a website like Atlas Obscura or Roadside America, or is featured in an obscure personal blog post from 2002. Earlier this week I visited one of these areas. To help keep it “off the map”, I’ll only be giving vague information on its whereabouts.
I’m going to go into some personal anecdotes here. During the pandemic, my family started homeschooling as a way to stay safe and healthy. My daughter thrived with homeschooling, so we’ve continued on with it. Proud parent moment here– my daughter is turning out to be a lifelong learner and is motivated and engaged in her education. When I got up on a sunny morning this past March, she was eager to tell me how she woke up early and couldn’t get back to sleep, so she’d been working on school on and off since 5am. She showed me what she’d done for schoolwork, then asked, “can we do something fun for the rest of the school day?” Of course I was down for that!
I scrawled down the phrase “carboniferous period” on a scrap of paper and handed it to her. “While I’m getting dressed for the day, look this up and be prepared to explain it to me in the car. We’re going on a field trip.”
“Where are we going?” she inquired.
“We’re going to the woods to break open some rocks!” I replied.
“Awesome!” she replied (she’s been really into rocks, crystals, and minerals lately).
Soon enough we were in the car; armed with hammers, chisels, and eye protection; and heading to a spot that I only had vague directions for. My daughter explained what she’d learned about the carboniferous period, and I finally disclosed that we were going hunting for carboniferous fossils. Her eyes widened with excitement.
Carboniferous Fossil Pit, Rhode Island Formation, March 2025. Photograph by Ophelia W. Ravenia.
The trailhead was easy enough to find, but we walked right past our actual destination once we got out into the woods. We circled around a bit before I found our spot. It was off the trail– just barely in line of sight. We eventually arrived at a pit full of fractured rock; chiseled out and busted up by the rockhounds who’d come before us.
Fossil Hunting, Rhode Island Formation, March 2025. Photograph by Ophelia W. Ravenia.
Carboniferous Fossils, Rhode Island Formation; Mainly Calamites, March 2025. Photograph by Ophelia W. Ravenia.
Despite being armed with hammers and chisels, we were able to find a lovely haul of plant fossils from the debris in the fossil pit. We found fossils of small delicate leaves, nearly invisible until the sunlight hit the rock at right angle, causing the fossil to shimmer. The stalks of ancient calamites– a horsetail-like plant that had dominated the landscape in ancient times, growing as tall as trees.
Reconstruction of a Whole Calamites Tree. Image courtesy of Falconaumanni via Wikimedia Commons. Licensed under Creative Commons Attribution-Sharealike 3.0.
After a few hours spent in the woods, it was time to pack up and head home, with a bag full of fossils and heads full of memories.
To find these carboniferous fossils, you’ll need to head to the Rhode Island Formation– a geologic formation covering much of the Narragansett Basin. That’s all the information I’m giving on the location.
More information on calamites is available here:
https://www.natureconservancy.ca/en/blog/archive/travel-back-to-the-carboniferous.html
https://www.uky.edu/KGS/fossils/fossil-month-12-2021-calamites.php
A report on the geology of Massachusetts and surrounding areas (including the Rhode Island Formation) can be found here:
https://pubs.usgs.gov/pp/1366e-j/report.pdf