Review Of The Natural History Of Niagara Falls

As if the human history of Niagara Falls on both sides of the border is not colorful enough, the natural history of the area is as colorful as the rainbow over the falls. Now, I have more to add to it. Let's begin with a review of the natural history of the Niagara region. This is my understanding of how Niagara came to be.

Around four hundred million years ago, what is now the Niagara region was at the bottom of a warm, shallow sea. Over the millennia, sediment collected on the bottom of the sea. As more sediment collected on top of it, the underlying sediment was compacted by it's weight into solid rock. This gradually formed the shales and sandstones that underlie the region today.

Eventually, small forms of life adapted to the conditions in the sea and their dead bodies were compacted in the same way to form limestones on top of the older, deeper shales and sandstones. The most recent major layer to form was a hard layer of limestone, also known as Lockport dolostone or dolomite.

Due to geological shifting, the sea drained of water and became dry land. Erosion set in. But because some layers of rock were harder and more resistant to erosion than others, erosion was uneven. One result of this is the escarpment at Lewiston-Queenston.

This escarpment is very old, around two hundred million years. It extends all the way from Watertown, NY to Wisconsin. This escarpment was not formed by tectonic shifting but by erosion. Geologists would refer to it as a cuesta. Under the Ontario Plain, the land below the escarpment from Lewiston to Youngstown and from Queenston to Niagara-on-the-Lake lie the very old shales and sandstones formed before life had adapted itself to the sea in which they formed.

The temperature varied due to various factors on earth and possibly, on the sun. It began to get colder to the north of the Niagara region. Eventually, it got cold enough so that the snow left from the last winter would not have melted by the time the next winter's snowfall arrived. Snow began to build up, layer after layer, year after year. The snow at lower levels was compressed into ice by the weight.

A vast sheet of ice formed in the north and began to work it's way southward, sliding due to the centrifugal force of the rotation of the earth. We have what is known as a glacier. The Niagara region experienced many glaciers, known as the Wisconsin Glaciers. The first of the last three arrived more than fifty thousand years ago and lasted for thousands of years. The Niagara area was covered by a sheet of ice that may have been more than a mile thick.

Then it got warmer for thousands of years. The second of the last three glaciers arrived maybe forty thousand years ago and may have lasted for eight thousand years. The most recent arrived about twenty thousand years ago and may have also lasted for eight thousand years. There were, of course, warm periods in between the glaciers.

After the last glacier withdrew, about twelve thousand years ago, water seeking lower ground found it's way from what we call Lake Erie to a point on the escarpment that is now Lewiston and Queenston. Actually, it did not take a very direct route. Excess water from Lake Erie formed a smaller lake to the north that natural historians have named Lake Tonawanda.

This lake was not very deep. It extended over most of what is now Niagara Falls, NY, Grand Island and, extended eastward to Rochester. Although the lake's eastern parts were shallower than it's western end. The deepest part of Lake Tonawanda was the south-western corner around what is now the Horseshoe (or Canadian) Falls. The strata is now slanted toward the southwest at about twenty feet per mile. What we now call Goat Island was probably under about thirty feet of water.

Lake Iroquois was an enlarged version of what is now Lake Ontario, extending all the way to the escarpment. There is a small terrace about thirty feet from the top of the escarpment called Eldridge's Terrace on the American Side and Roy's Terrace on the Canadian side. A terrace is a flat strip of land which interrupts the slope of a hill or escarpment. This terrace is actually a former beach formed by wave action on the surface of Lake Iroquois.

As water found it's way to the edge of the escarpment at what is now Lewiston-Queenston, it drained over the edge and fell about thirty feet into Lake Iroquois. This was the beginning of the falls.

At the time, about ten thousand years ago, this was not the only outlet of Lake Tonawanda to Lake Iroquois. There were actually five altogether. Traces of the others can still be seen on the escarpment today at Lockport, Gasport, Medina and, Holley.

So water draining from the Great Lakes basin flowed from what is now Lake Erie into the smaller Lake Tonawanda and then through those five established routes over the escarpment into Lake Iroquois. Eventually, these other outlets were left high and dry and the Niagara River was the only route that the waters of Lake Tonawanda, and Lake Erie behind it, took to Lake Iroquois.

Lake Iroquois is, of course, an enlarged version of what we now call Lake Ontario. It extended all the way to the escarpment so that what is now Lewiston, Queenston, Youngstown and, Niagara-on-the-Lake were underwater. The other side of the lake is what is now Toronto.

There is no comparable escarpment in Toronto to form the other side of the lake. But if you follow a north-south street northward in Toronto, Yonge St. for example, you will notice that the ground gets higher and higher. This is what once was the northern shore of Lake Iroquois.

When water began pouring over the escarpment from what we now call the Niagara River into Lake Iroquois, another factor came into play. The top layer of rock, the Lockport Dolostone, was much harder and more resistant to erosion than the underlying layers of limestone. The reason for this is that Lockport Dolostone is actually magnesium carbonate, while ordinary limestone is calcium carbonate.

This caused the underlying layers to be eroded by the falling waters more quickly than the top layer. Chunks of the top layer would remain intact but would break off when it's underlying supporting layers were eroded away by the falling water.

The effect of this was that the water always fell straight down, rather than as a sloping rapids, and gradually eroded it's way backward into the escarpment. Niagara Falls had been born.

Not too far from where the falls began, we can see that the level of the lake and the lower river (below the falls) must have been considerably higher than it is now. Smeaton's Ravine is on the Canadian side of the gorge between the Lewiston-Queenston Bridge and the Sir Adam Beck Power Plants. It is about level with the Floral Clock. This ravine is the remains of an old waterfall that poured into the gorge about ten thousand years ago after the falls had eroded it's way southward from where the ravine is now located.

What is interesting about the ravine is that the erosion that the former falls has made in the rock does not go all the way down to the water. The reason why is that the river, and thus Lake Iroquois (now Lake Ontario) was at a much higher level then than it is now.

The gorge, or canyon, that the falls formed when it gradually worked it's way southward to where it is now from where it started at Lewiston-Queenston is narrow around where the power plants on both sides of the border are located. This is because at that time, it was only the water of Lake Erie that was flowing over the falls. The upper lakes had another route to the St. Lawrence River and the sea by river systems further north in Ontario. So, only about 15% of the water that flows over the falls now was flowing then.

The progress of the falls through this section of gorge was a little more complicated than this. For example, at one point a smaller falls separated from the main falls moving southward. But, the main falls overtook the smaller falls and cut it off. The result was an island in this part of the river, similar in principle to today's Goat Island. As the falls moved further, away from this island, it collapsed. The result is what we now call the Niagara Glen on the Canadian side.

As the falls eroded it's way southward, it eventually encountered a buried river gorge from the former geological era, the warm period between the second and third last glaciers to cover the area. Remember that the time since the falls began is following the last, glacier.

In the last warm period before our own, from about 32,000-20,000 years ago, a powerful river flowed from the area Where Lake Erie is now to a break in the escarpment it had eroded at the Canadian village of St. David's, a few kilometers west of Queenston. The river may have been similar to the present Niagara River.

There must have been a falls to carve out the gorge. The last glacier had filled in this river gorge with rocks and other debris. However, the debris with which the glacier filled in this old river gorge was much looser than the sorrounding solid rock. It was more like a landfill and not solid rock.

When the falls encountered this buried river gorge, it had a much easier time digging into it with the force of the falling water. It was so much easier that the falls changed direction to follow the buried river gorge as long as possible. The place where this meeting between the new Niagara River and the buried St. David's River, as it is called, is what we now know as the Whirlpool.

It is very easy to see the sudden change of direction that our Niagara River undertook at this point. We can see that this new direction forms a straight line through the Whirlpool to the vast eroded gap in the escarpment at the village of St. David's. The St. David's River, in the previous warm era, must have been very steep and fast-flowing because the lower river rapids in the Niagara River between the Whirlpool and the Whirlpool Bridge, the section of the former river that our present Niagara River re-excavated.

After the falls had moved southward past the area of the present Whirlpool Bridge, it's natural flow ceased to match the direction of the buried gorge and it continued eroding it's way slowly through solid rock as it had been doing since it encountered the buried gorge. The re-excavation of the buried St. David's Gorge must have been very fast, geologically speaking, compared to the falls working it's way slowly through solid rock.

The reason for the Whirlpool that now exists is that a whirlpool is what a fast-flowing river like the Niagara carves for itself when it makes an abrupt turn for some reason, in this case finding the looser fill of the buried gorge. A fast-flowing river is like a fast car, it cannot just turn on a dime. A whirlpool like ours serves the same purpose as the semi-circular ramps on a highway. A fast-moving car needs it in order to make a turn.

The next significant event in the natural history of the area occurred when the falls had worked it's way southward to Hubbard's Point. This point is a high point on the Canadian side as seen from the American side. The best place to see it is from the Gorge Discovery Center, formerly known as the Schoellkopf Geological Museum. It is built on the former site of the Schoellkopf Power Plant, which collapsed into the river in 1956.

Hubbard's Point is the high point of a ridge. Seen from the American side, it is at the third street north from Michael's Inn on the Canadian side. Michael's Inn is the white building not far north of the Canadian side of the Rainbow Bridge. If you are on the Canadian side, Hubbard's Point is where Eastwood Ct. meets River Rd. You will notice that the point is the high point, the ground on either side is lower.

Hubbard's Point is actually the top of a ridge, known as the Lyell-Johnson Ridge. The falls, working it's way southward, had to cut through this ridge. Since this ridge is the highest point in the falls' journey southward, that means that the surface level of Lake Tonawanda would logically begin to drop after the falls had cut through the ridge at Hubbard's point.

You may notice that the falls is now at the bottom of an ancient valley of which Hubbard's Point is the high point to the north. The falls, eroding it's way southward, cut through the ridge that was at Hubbard's Point about thirty-five hundred years ago.

I saw a diagram in a book depicting the boundaries of Lake Tonawanda. There was no actual map of where the shores of this lake were located relative to the streets of today. So, I went out and looked for the ancient shores myself. It was not difficult to find.

Going north on Military Rd. in the Town of Niagara, it is easy to notice the sudden increase in elevation as you pass K-Mart. This increase in elevation levels off not far north of Packard Rd. and is visible across the northern section of the K-Mart parking lot. When you travel southward on Military Rd. in the Town of Niagara approaching Lockport Rd. and K-Mart, it seems as if you are looking out over a lake. A few thousand years ago, you would have been.

Going north on Walmore Rd. in Wheatfield, the same type of sudden elevation is obvious just before reaching Lockport Rd. The terrain was obviously sculpted during the construction of the railroad bridge. But, the increase in height is unmistakable and is a continuation of the ancient northern shoreline that is also visible in front of K-Mart.

Further east, going north on Buffalo Rd. toward Sanborn, just after passing Lockport Rd., the same kind of sudden elevation is apparent. Although, the elevation increase is obviously becoming less pronounced as we move eastward, away from K-Mart.

Looking across the farms from Lockport Rd. toward Bergholz, the decrease in elevation is noticable as you look southward toward the Niagara River. The same gradual southward slope can also be seen in the LaSalle section of Niagara Falls, NY. When on Niagara Falls Blvd. it is fairly easy to see the southward slope of the land when looking straight down the numbered streets from 77th to 82nd Sts.

The wide Upper Niagara River, from Grand Island to the falls is, of course, the shrunken remains of lake Tonawanda. As we know, the lake began draining from it's northern shore (K-Mart) toward the river of today when the falls finally cut through the ridge at Hubbard's Point about two thousand years ago. Lake Tonawanda had formed after the last glacier withdrew about twelve thousand years ago. The lake extended eastward to the Rochester area.

In Lake Tonawanda, there was an island that natural historians refer to as "Niagara Island". It was near where the American Falls are now. It's former shoreline was also easy to find. On Pine Ave., looking from around where McDonald's is now toward Portage Rd., the increase in elevation is very obvious. Portage Rd. is on what was the eastern shore of Niagara Island. Going north on Portage Rd., toward the Library, it is easily visible that Portage Rd. is on higher ground than 11th St. Looking northward on Main St. from the Niagara Falls Library, it becomes obvious that the ground is getting lower, this represents another former shore of Niagara Island.

This ancient shore can also easily be seen on streets running parallel to Pine Ave., such as Walnut and Ferry Avenues, also just east of Portage Rd. The higher ground on the mainland opposite Goat Island represents another former shore of Niagara Island in Lake Tonawanda.

A final important factor in the area's natural history is what we know as the Niagara Falls Moraine. A moraine is basically a mass of rocks, earth and, debris that is dropped by a glacier after having been gradually picked up elsewhere.

Near where the falls are now, we notice that there is high ground on the Canadian side, upon which the observation towers and the skyscraper hotels are built, but there is really no corresponding high ground on the American side. This high ground extends from the area of the whirlpool to just east of Dufferin Islands.

This moraine is important because it caused the lower river to flow northward instead of westward. If this high ground had not been there, the river may have ended up meeting the escarpment anywhere between St. Catharines and Hamilton.

I have noticed that we only have to look at a map to see signs of how vast was the volume of meltwater from glaciers at the end of the last ice age. A prominent feature of Lake Erie is the Long Point Peninsula extending far out into the lake from the Canadian shore. This peninsula was formed by sediment carried by the rush of water from melting glaciers in the Brantford-Cambridge-Kitchener area.

This peninsula forms a straight line and formed where sediment-laden discharge water from the melting ice sheet decreased in velocity as it mixed with the water of what is now Lake Erie. The peninsula points almost directly eastward from the shore from which it originates. The line which the peninsula forms is clearly a vector line of the discharge flow of the meltwater and the eastward movement of water in the lake.

Here is a map link http://www.maps.google.com/

If the water of Lake Erie had been relatively still at the time of the melting of the glacier, the axis of the Long Point Peninsula would be north-south instead of almost directly east. Since the main direction of the flow of meltwater on land here was southward. We only have to glance at a map of the lake to imagine the furious rush of water through it from melting glaciers further west.

The water from the melting glaciers must have been moving at high speed to be able to carry all of the sediment necessary to form the peninsula, yet the peninsula was pushed almost directly eastward instead of forming along the roughly north-south axis that it would have if Lake Erie was as still as it is today.

The entire lake must have resembled a raging river for at least a while, much like the broad upper Niagara River is today. This effect is possible due to the shallowness of Lake Erie. It is by far the most shallow of the Great Lakes, the eastern Buffalo end is deeper than the western Detroit-Toledo end.

The volume of meltwater from South-Central Ontario into Lake Erie can be estimated by the volume of sediment required to build the Long Point Peninsula. Then, by considering the eastward angle formed by the peninsula in the lake, it will be possible to estimate the former flow of water through Lake Erie and thus get an idea of the scope and depth of the glacier.

Now, back to Niagara Falls and the former Lake Tonawanda. We can see how extremely rapid the flow of water through Lake Erie must have been at the close of the last ice age. There is no evidence in the Niagara Gorge around Lewiston-Queenston of a vastly increased flow of water through in the very early days of the river and the falls. So where did all of this additional water go?

My answer is through the four now-dry outlets of the former Lake Tonawanda, mentioned above, as well as the Niagara River. The present river just happened to be the lowest of the five outlets so when the meltwater from the glacier was gone and the flow of water through Lake Erie diminished toward what it is today, only the Niagara River remained as an outlet for water from the upper Great Lakes over the escarpment.