Seventh Workshop Covers Connecticut Geology

We have been very lucky. It doesn't seem to matter what Saturday in May Menunkatuck Audubon chooses for our educators' workshops - the weather has always been perfect for what we have planned. Four years ago it rained the night before our "Amphibians of Spring" workshop, clearing to a damp, humid morning. Optimum conditions if you're searching for salamanders and frogs. Our bird, insect and intertidal workshops all happened to fall on gloriously bright, warm, sunny days that held the promise of summer days to come.

This year's workshop was held on May 4, a clear and bright Saturday, though a bit windy. It wasn't a great day for bird or insect watching, but quite nice if you're studying the geology of Connecticut. After all, the rocks weren't going anywhere.
Over shade-grown coffee, bagels, muffins and fresh fruit, Ralph Lewis, Connecticut's State Geologist, led our fourteen participants though the history of Connecticut's geology with a morning slide presentation and discussion. Little geology facts we learned included such tidbits as: 1) the reason the lands north of Hartford are so flat is due to the area once being a huge lakebed. 2) The beautiful stone we know as pink Stony Creek granite isn't actually a granite anymore. Granites are igneous rock, but our local "granite"' have been metamorphosed into, yes, metamorphic rock. They are really granite-gneiss (nice). 3) Different rock types erode at different rates, causing some to remain elevated. This is known as 'differential erosion.' 4) The tops of our trap rock ridges are drier and hotter than the surrounding lands. They can support plant and animal species from more southerly climes. Conversely, the talus slopes below the ridges are cooler and can support life found in more northerly regions. These are very special microhabitats.

A quick walk outside onto the grounds of Melissa Jones Elementary School in North Guilford revealed conglomerate, igneous and metamorphic rock. Ralph discovered a rather plain rock, about twelve inches in diameter that was easily overlooked by the rest of us. As he turned the rock over we could see why it was so special. The underside bore the markings of a rock that had been scraped across other rocks many, many years ago. A glacier had dragged this rock and deposited it here!

We proceeded to Chatfield Hollow State Park in Killingworth to view (and climb) the rock formations and enjoy lunch. We then visited the glacial moraine at Meigs Point at Hammonasset Beach State Park in Madison. Ralph continued to tutor us as we stood on the observation platform and viewed Falkner Island. As we walked among the moraine boulders deposited by a glacier so long ago, Ralph quizzed us on each rock's identity. Was it a conglomerate, an igneous or a metamorphic rock? Was it sedimentary? Basalt, granite, gneiss or something else?

We ended the day with a better understanding of Connecticut's geologic past and how it shaped our state. All in all, it was a very gneiss day.

Submitted by Cindi Kobak
Photos by Cindi Kobak