Michael Conte, Jr.
As we have seen, there have been many geologic forces that have helped shape and are still shaping the Earth. The geologic forces that acted upon the land mass we call Connecticut produced four very distinct areas: Central Valley, Coastal Lowland, Western Highland and Eastern Highland. The forces that played a key role in determining these include volcanic and mountain building activity, erosion and glaciation.
The area of Connecticut was at one time a mountain that had been formed by continental collision. (In the past this process has also formed the Appalachian Mountains and Highlands in Scotland and Scandanavia.
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) Nearly 180 million years ago as the Atlantic Ocean began to split apart, fracturing occurred (fracturing results from the Earth’s movements or contractions of Igneous rock as it cools
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), accompanied by volcanic activity which left lava to form the Hudson River Palisades. The lava cooled and became trapped by layers of sand and gravel into the area known as the Connecticut Valley. This area extends from Vermont, through Massachusetts and Connecticut, ending in Long Island Sound. (see diagrams C and D)
The continual process of erosion (wearing down of a surface) was taking a mighty toll on our mountains and transporting layers of sand into the fault area, The Connecticut Valley. The geologic forces that were active throughout the Earth had not yet finished with Connecticut. Forces within the Earth pushed on either side of this valley and the hardened trapped lava (traprock) which was very strong, cracked and broke through the surface in many areas of the state. Sediments which had been continually deposited on this area were compressed into Sandstone as the fault continued its downward motion. As water eroded the softer sand and gravel surrounding the traprock, the Central Valley began to take the shape we see today. Other cracks also occurred which account for the variety of landscapes we have in our state. The sediment that was eroded away during this time was deposited in a coastal plain, part of which we now call Long Island.