Vermont’s new Bedrock Geologic Map will be unveiled Wednesday in a ceremony at the State House.
A team of researchers with the U.S. Geologic Survey has been working on the new map since the 1980s. The last such map was created in 1961.
Research geologist Nick Ratcliffe has been a part of the U.S.G.S. team. He says the oldest known rock formations in Vermont and in the entire Appalachian chain can be found in the area near South Londonderry.
"The north/south pattern that we do see is a regional pattern. It’s something that really trends along the whole Appalachian mountain front because they’ve had a similar origin," Ratcliffe said.
While the underlying geology of the state has been basically unchanged in the 50 years between map editions, there have been major progressions in the science of geology.
They include the development of Plate Tectonic Theory and more accurate dating of minerals.