This week, we’ll venture back to the Triassic period when Pangaea began to split apart, forming fault-bounded rift valleys along what is now the east coast of the United States. Swampy lakes within these basins attracted dinosaurs—both herbivores and carnivores. Let’s visit two locations where you can experience the trackways these prehistoric creatures made. 🦕
Sharon Lyon
Editor, GeoLifestyle
Dinosaur State Park, Rocky Hill, CT
Daderot/ Wikimedia Commons
Located within the Connecticut River Valley, the Hartford Triassic Basin formed from Pangaea’s breakup 220–170 million years ago. Formations in the basin range from the late Triassic to early Jurassic and belong to the Newark Supergroup.
Area geology: By the early Jurassic, the basin was an asymmetrical half-graben with a border fault on the east side of the rift.
Large alluvial fans prograded into rift valley lakes with broad shores.
Cycad, conifer, horsetail, and fern forests supported a diverse fauna of small to medium-size dinosaurs, mostly lizard- and crocodile-like reptiles. Fish swam in the lakes.
History and dinosaurs:
In 1966, more than 2,600 individual dinosaur footprints were discovered in central Connecticut.
Most were classified as the ichnotaxa Eubrontes, a dinosaur possibly resembling Dilophosaurus (theropod with a crested skull).
In 1968, more than 750 additional tracks were discovered west of the original site. A permanent geodesic dome was built over the second site in 1978, which you can tour today.
The original track site was reburied to prevent erosion, with the hopes that paleontologists might one day excavate and preserve it.
Paleontologists have identified additional footprints as Anchisaurus (early sauropodomorph), Aetosaurus (ancient, herbivorous relative of the modern crocodile), Grallator (small, fast predatory therapod, similar to Coelophysis), and Otozoum (early sauropodomorph with four toes).
Early sauropodomorphs were related to the larger sauropods of the late Jurassic but stood on two legs.
Trip tips:
Take a walk: Enter the geodesic dome and meander along the glassed walkway built across the dinosaur trackways. View the dioramas of Triassic and Jurassic environments, the fossil collections, and hands-on interactive exhibits.
BYOB (Bring your own bucket): You can make a cast of a real Eubrontes footprint. Bring a five-gallon bucket, 1/4 cup of cooking oil, 10 pounds of Plaster of Paris, rags, and paper towels.
Stop and smell the flowers: Stroll through the Arboretum, which contains more than 250 species of Mesozoic plants, trees, and shrubs, reflecting the paleoenvironment that the dinosaurs inhabited.
A message from AAPG Academy and AAPG's Energy Minerals Division
Join AAPG Academy and AAPG's Energy Minerals Division (EMD) on 17 June at 9am CDT as we explore the emerging trends and developments that are making a difference in the quest for critical minerals and rare earth elements.
Our conversation will be led by two expert speakers, Ashley Douds and Aaron Ball, who are the president and president-elect of AAPG's Energy Minerals Division, respectively.
Douds will begin by examining recent trends in energy minerals with a focus on the state of Indiana and the Appalachian Basin. She will be followed by Ball, who will take an even closer look, analyzing brines with laser-induced break spectroscopy and how they can be used to predict the presence of light and heavy elements.
Theropod dinosaur footprint; At the DinoWalk, Luck Stone Quarry.
The Triassic Culpeper Basin formed the same way as the Hartford Triassic Basin—a fault-block graben due to continental rifting.
Area geology:
Two hundred and fifteen million years ago, streams flowed southward into a large playa lake within the Culpeper Basin, depositing laminated gray-to-black shales.
These rocks have been classified as the Groveton Member of the Bull Run Formation, within the Newark Supergroup.
Luck Stone Quarry in Stevensburg, Virginia, is positioned near the southern end of the ancestral lake.
Ripple marks preserved in the shales indicate wind-driven currents in the lake.
The lake then dried up for a period of time, as is evidenced by mud cracks, before re-expanding.
Dinosaur footprints: Beginning in the 1980s, paleontologists have uncovered more than 4,800 fossil footprints in two levels within the quarry.
In an upper level of the quarry (now removed by excavation), paleontologists discovered 20 trackways of six dinosaurs: two sauropods and four carnivores (including Grallator and Eubrontes).
In the lower level, currently visible, crocodile-like phytosaurs made swimming prints and belly prints in the mud, and plant-eating aetosaurs walked with a quadrupedal gait.
In addition, paleontologists have identified 20 dinosaur trackways of the theropod Kayentapus minor, a medium-size ceratosaur, up to 500 pounds in weight. These dinosaurs sprinted across the lakeshore at up to 24 miles per hour, as determined by the length of their stride.
DinoWalk: Your opportunity to see the dinosaur trackways comes once a year when Luck Stone Quarry opens to the public for a DinoWalk, in conjunction with the Museum of Culpeper History.
This year’s event in May offered tour opportunities to museum members one day and the general public the next.
Tickets go on sale each year a month in advance of the event and are limited to one ticket per family. One carload of visitors gets to spend one hour on the quarry floor.
For next year, keep an keen eye here, as tickets sell out quickly.
If you miss the event, you can visit the Triassic Gallery of the museum, located in downtown Culpeper, Virginia, anytime.
Old House Vineyards, Culpeper, VA
Located on a beautiful farm property, Old House Vineyards is a perfect place to relax.
After touring Luck Stone Quarry, meander across Germanna Highway to Old House Vineyards.
Trip tips:
Sample from the vineyard’s selection of wines, craft beers, or small batch spirits.
Have lunch on the weekends at the venue’s Green Ribbon kitchen.
Enjoy all these activities while imagining the subterranean dinosaur footprints under your feet! Cheers!
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