Geology of Connecticut
Geology at a Glance
The State has three major geologic regions—the eastern and western highlands, each composed of older, metamorphic rock, and a central valley, largely composed of basalt overlain by sandstone.
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History
- 1842 James Gates Percival – Report on the Geology of Connecticut
- In 8 months surveyed the state East to West at 4 mile intervals. The resurveyed again East to West at intervals between the former to bring him in contact with each of the 4600 square miles of the state.
- He collected estimated 8000 specimens, as well as noted dips, bearings, and formations making it likely the most accurate survey ever conducted of the state
- However, despite two years of survey and he was “rushed” by the state legislature and wrote a “hasty outline” of over 500 pages
- 1906 Manual of the Geology of Connecticut and Preliminary Geological Map by William North Rice and Herbert Ernest Gregory
- 1924 H. H. Robinson – State Geological and Natural History Survey
- 1977 The Connecticut Assembly names Garnet the state mineral
- 1985 John Rodgers (compiler) Bedrock Geological Map of Connecticut
- 1842 James Gates Percival – Report on the Geology of Connecticut
Links
- Bedrock Map
- State of Connecticut Geological Survey
- Metacomet Ridge
- Caves of Connecticut
- Connecticut’s Garnet Trail
- Meteorites in Wethersfield and Weston — Unexplored
Geologic Reports of Parks
State Parks
- Bluff Point – Surficial and bedrock geology can be studied here. Of note is the beach composition and the rocky bluffs at the point
- Bolton Notch – At the very top of the “notch” is marble exposure and along the face are several caves large enough to accommodate a human. Calcite is the predominate mineral in the marble.
- Campbell Falls – The park is covered in glaical till, the falls are part of the Dalton Formation with nearly vertical granitic gneiss
- Chatfield Hollow – Monson Gneiss, rockfall caves
- Day Pond – Brimfield Schist
- Dennis Hill
- Devil’s Hopyard
- Dinosaur – A 200 million year old sandy lakeshore is now a sandstone layer of the East Berlin formation preserving the tracks
- Gay City
- Gillette Castle
- Hammonasset Beach
- Haystack Mountain
- Kent Falls
- Kettletown
- Macedonia Brook
- Mansfield Hollow
- Millers Pond
- Mount Tom
- Osbournedale
- Penwood
- Putnam Memorial
- Rocky Neck
- Sherwood Island
- Sleeping Giant
- Southford Falls
- Wadsworth Falls
Other Parks”]
