Instead, the reef builders during this period in earth history were animals called bryozoa, stromatolites, stromatoporoids, sponges, and algae. Other citizens of the reef were cephalopods, gastropods, crinoids, and trilobites.
So instead of calling it “the world’s oldest coral reef”, Dr. Charlotte Mehrtens, Professor of Geology at the University of Vermont has called it, “the world’s oldest reef in which corals first appear.”
Stromotoporoids in the walls of the Fisk Quarry Preserve
The Chazy Reef on Isle La Motte: The Quarries
In the past hundred years geologists have determined that much of the island bedrock, the beautiful black and grey limestone that had been quarried for many years, was actually the fossil remnants of an ancient reef. A Harvard geologist in 1924 called it “the oldest coral reef in the world”.
Since that time researchers have determined that though ancient corals are found here, coral, during this period of earth history, was not one of the predominant constructors of the reef.
Isle La Motte black “marble” or limestone in the floor of the Vermont State House.
Throughout the 19th Century the only clue to Isle La Motte’s future importance to scientists was the fact that five or six active quarries on the island produced a uniquely beautiful black and grey limestone.
It could be polished to a marble like finish and was sold to such distinguished customers as the Vermont State House, Radio City Music Hall and the National Gallery of Art.
Quarry workers on Isle La Motte may have wondered at the strange forms that often appeared in the rock which they were drilling and loading into shipping boats on Lake Champlain. These forms were later identified by paleontologists as marine fossils of astounding antiquity.
Isle La Motte gastropod in
the Vermont State House.
The Fisk Quarry in the 1800s
Bryozoa
Stromotoporoid
Sponge
Cephalopod
