“The story of Connecticut you are beginning to read has two parts, the place and the people. Either part can be studied alone, but to produce the whole story of Connecticut they must be put together. The story began before any people lived there… Nevertheless, most of our story will be about the people…
The Land and Its Formation
Back many thousands of years ago, when the world was young, the mountains of Connecticut rose thousands of feet into the air. As rain fell producing brooks and rivers, the flowing waters wore away the surface. Rapidly flowing water has a lot of power to wear away rocks, and it carries away small particles of them. When the speed of the water in a river slows down, these particles are dropped in the river bed. After any rainstorm you can see this happen. As the water flows rapidly down hill in the gutter of a street it sweeps everything along with it. But, where the ground becomes level, the water moves more slowly, and a pool of water forms. Here the sand and gravel fall to the bottom. After the water drains away or dries up you can see the kind of material that the water has been carrying spread out in thick layers of sand, mud, or gravel.
If enough times passes, even high mountains will be worn down to a level surface. This was happening in Connecticut when a great event took place. A tremendous crack developed across the state, roughly north and south, from the sea to Massachusetts, and a big block of rock dropped down much like the diagram. Scientists call it a fault.
After this happened a long period passed while the rains continued to fall. Much of the upland, the higher portions on both sides of the crack, was washed down into it, filling it with great layers of sand. From time to time, new cracks appeared in this big valley and volcanoes burst forth, throwing out red hot rock (lava) that spread in thick layers on top of the sand. Then the volcanoes would quiet down and very fine particles of clay, sand, and gravel would be washed down and spread out on top of the now cooled lava.
A sort of sandwich with many layers was produced, as you see. The dark layers are called trap rock in Connecticut. They were once red hot and flowed like water. The lighter sections in the picture are layers of sand, gravel or clay. These three words mean different bits of material of different sizes. You all know what sand is like; gravel is made up of larger particles, but the particles of clay are so small you can hardly see them.
Next a new force appeared. This was a squeeze that brought the sides of the valley closer together. If the rocks in the valley had been soft they would have crumpled up as you can crumple a piece of paper. Instead they were hard and they broke, one piece sliding up on top of the other as you see here.
Of the three kinds of rock in the valley: the sandstone, shale made from clay, and the traprock, the sandstone was the most easily worn away under the influence of running water. Eventually the valley began to look the way you see it today. The rivers wore out their valleys in the soft sandstone and the trap rock was left standing up as a series of long hills. Some of their names are West Rock and East Rock in New Haven… There may be a trap rock ridge near to you. If so try to visit it and collect samples of sandstone, shale or trap rock. Notice how hard the trap rock is. It is used to make roads today…
One other kind of rock is found in Western Connecticut. This is limestone. It is produced by limey materials deposited in the sea that once covered this area. Such rocks can be found from Danbury noth along the Housatonic River into Massachusetts. They are very useful. Blocks are cut out of the hills and used for building purposes or are ground up to make lime which is used in plastering the walls of our houses. Lime is also used in agriculture.
The last big event in making the present land surface was the ice age. Many thousands of years ago the climate began to get colder. It became so cold that to the north in Canada, the snow that fell during the winter period did not all melt in the following summer. Year after year the snow piled up higher and higher. Finally in the lower levels the snow became ice by being squeezed together, much as you can squeeze a snowball into ice. When this happened the lower levels of the ice which were under great pressure began to move. You can understand how this happened if you remember the last time you put too much jelly in a sandwich. Then, when you bit into it, your teeth put pressure on the outside layers and the jelly was squeezed out. The ice was squeezed out in the same way.
The ice moved very slowly, only a few feet a day, but it kept coming southward as more and more snow and ice piled up. As it came it rode up over the hills in its path. At its furthest point of advance, all of Connecticut was covered and the edge of the ice lay on Long Island. The ice pushed ahead of it or picked up all of the loose material in its path. Some rocks were frozen into its lowest levels and acted like a piece of very coarse sandpaper, smoothing down the rocky surface. Many times deep scratches were made that can be seen today. Although the glacier, as the ice sheet was called, did make some changes in the surface of Connecticut, all the larger hills and valleys were here before the glacier.
Eventually the summers became warmer and the glacier began to melt. It took a long time for all of the ice to melt. Scientists think that it was perhaps 500-800 feet thick over Connecticut’s southern part and much thicker further north. As you could guess, melting produced great rivers of water which flowed from the ice sheet, carving the valleys deeper and carrying large quantities of clay and sand down to the sea. Some of it was dropped along the way in the lakes that filled most low spots in Connecticut after the glacier melted. Such deposits are widely scattered around the state.
The clays are used in making bricks and are found at many locations in the Quinnipiac and Housatonic valley. Sand deposits are even more widely distributed. Many of them are being used today to supply sand and gravel used in building. If you can visit a sand deposit, you may see the several layers of sand that were laid down year after year as the ice sheet melted back. A visit to a brick yard will show you the yearly layers of clay that were deposited in what was once a lake.
In addition to these deposits of clay and sand the larger rocks that the glacier had picked up and carried with it were dropped directly on the ground. Residents have wondered how these great rocks got to where they now stand. The answer is they were dropped by the glacier…
When the ice sheet finally melted away the land lay bare of all vegetation; a great rocky, muddy region. This happened about 10,000 years ago. Soon seeds came in. Some were brought by birds and some were blown by the wind from… regions that were never covered with ice. Other seeds that had been buried by the ice and had slept during the long ice age began to grow with the warmer temperatures. In a few thousand years Connecticut again had a cover of plants, and the birds and animals came back…
A low coastal strip only a few miles wide extends along the seacoast from New York to Rhode Island. It is the edge of the old rocky surface broken by many small rivers and three large ones, that have carved out valleys which today reach to the Sound. Some valleys form harbors… [such as] New Haven… Because the coastal area is relatively level it makes a smooth surface on which many of the first settlements were begun…”
-Excerpt and (top) image courtesy of the Internet Archive, University of Connecticut Libraries, “The Connecticut story,” by Joseph Bixby Hoyt, 1961