One of the most interesting geological sites in New England is Greenfield Massachusetts. Tucked between the Connecticut River and the Berkshire Hills, this area contains geological marvels from glacial evidence to the occasional dinosaur footprint. Check the link below for a map of the Greenfield area.
Greenfield has a very diverse collection of rock, displaying all three major rock types: igneous, sedimentary and metamorphic. Of these rocks, perhaps the most interesting is the basalt deposits, which spilled out of the Eastern Border Fault, caused when the ancient continent Pangea split apart. This lava is extremely interesting because it contains radioactive material. Radioactive minerals, due to their half life, can be used to measure the age of the rock. This rock dates back to approximately 194 million years ago, placing it in the Late Triassic to early Jurassic era.
This, however is far from the most ancient information we have about the Greenfield area. In fact, we know that approximately 600 million years ago the entire Greenfield area was deep under the old Atlantic ocean, which is often called the Iapetus Ocean. It was not until 400 million years ago that Greenfield rose above the surface of the ocean, when the ancient continent Godwana, which is now part of Africa, collided with what is now known as North America. This collision of tectonic plates pushed Greenfield and much of the area around it up out of the ocean, transforming it into a huge mountain range the size of the Himalayas. Over time the area was eventually eroded into the flat plain it is today.
The thing that attracts most non-geologists to this are though, is the discovery of dinosaur footprints in the red sandstone that makes up the bank of the Connecticut River. These footprints are interesting because, although they clearly prove that dinosaurs were at one time present in the area, its hard to definitively prove the species of dinosaur. This is because, while footprints are common, there have been no findings of bones to accompany the prints. It seems likely, based solely on these prints, that the most common dinosaur was the Dilophosaurus. This 20 foot long, 6 foot tall dinosaur is known for leaving 12 to 18 inch prints. This species much resembles a miniature version of the infamous Tyrannosuarus. For more information on the Dilophosaurus, check out the link below.
http://www.myjurassicpark.com/dilophosaurus.html
