Tonawanda And The Niagara River

I cannot see that anyone has ever explained why the Niagara River formed where it did and why. Also, the terrain of the City of Tonawanda is a marvel of secondary glaciation.

It was inevitable that a passage would form for water to flow from the upper Great Lakes to Lake Ontario. In the previous warm period between the ice ages, there was a river in the same general area as the present river. It is known as the St. Davids River for the Ontario village of that name.

To understand why the Niagara River of today begins where it does at Buffalo-Fort Erie, let's first consider the westward slope to the underlying rock strata that creates the upper rapids above the falls.

The major slope of the strata in the area is to the south. This can readily be seen in many places; Military Road in the Town of Niagara south of Lockport Road, looking southward down the numbered streets in the 70s from Niagara Falls Blvd. in LaSalle. From Lockport Road, looking across the farms toward Bergholz, the gradual drop along Nash Road looking south from Niagara Falls Blvd and, from the American side of the falls looking along the top of the gorge on the Canadian side.

Here is a map link with satellite imagery if you want to look at the area http://www.maps.google.com/

But there is also a westward slope to the underlying strata as we get close to the lower river and the falls on the American side. On the Canadian side, the slope is eastward but is more obscured by the Niagara Falls Moraine than on the American side. The best place to see this eastward slope is on Thorold Stone Road.

These two slopes, but not the larger-scale southward slope in the area, are part of the underlying Niagara Valley that I pointed out and explained previously in this blog on the posting by that name.

At the end of the last ice age about 12,000 years ago, the thick glacier that covered the area began melting and breaking apart with vast icebergs sliding across the slope of the land, creating so much of the landscape that we see today. The sliding ice carved out the lake that once covered much of the area for about 8,000 years after the end of the last ice age until it drained. This is known to natural historians as Lake Tonawanda and I have referred to it frequently on this blog.

Above the falls, where the slope of the rock strata is predominantly westward, masses of ice slid across and compacted the ground that we now see at Queen Victoria Park and Clifton Hill on the Canadian side by the falls. It can also be seen looking eastward from Stanley Avenue along side streets such as Cedar, Huron and, Elm.

So, any icebergs from the melting glacier that happened to slide into this zone went westward and this formed the western boundary of the former Lake Tonawanda. The path of one such berg left us with both Burnt Ship Creek on Grand Island and the American Falls, as I described in the posting by that name.

Further eastward, ice was also sliding along the general southward slope of the land but where the westward slope ceased, roughly around where Baseline and Stony Point Roads on Grand Island run north-south, the ice continued sliding southward. It plowed up the land before stopping and melting to form what would become the southern shore of Lake Tonawanda.

If we head north on Delaware Street in Tonawanda, we notice a definite drop in elevation from Syracuse Avenue to Grove Street. There is a similar drop on the parallel Main and Wheeler Streets and this was once the southern shore of Lake Tonawanda.

It is not difficult to see why this formed. Some distance to the north, on Niagara Falls Blvd, if we look south on Nash Road, we can see the gradual drop in elevation that brought the ice sliding into Tonawanda at the end of the ice age.

In Tonawanda near the river, we can see that Broad Street is actually in a shallow basin. If we look southward on Seymour Street from the area of the bridge over Tonawanda Creek, we notice a short but definite drop in the road level and that there is a noticable downward slope going southward.

Let's call this low area the "Tonawanda Basin". It is formed by a natural dike created by sliding ice at the end of the last ice age. This is because after the main slide of ice formed the slope described above, a lesser amount of ice plowed up the ground around it before coming to a halt to create the basin. The North Tonawanda Moraine that I described in another posting on this blog is from a similar later slide of ice.

Also in North Tonawanda, there is a short, shallow slope that I find very interesting. From Webster Street, there is a little drop in elevation down to parallel Manhattan Street, along Goundry, Tremont and, Sweeney Streets. This slope actually represents the transition from a lake to a river that occurred about 3500 years ago as Lake Tonawanda drained due to a channel cut by the erosive power of the falls.

When the surface of the water was above this slope, it was certainly a lake, but when it moved below this slope, it became the Niagara River and it was the now fast-flowing waters of the new river that carved the slope.

This short slope must have formed when there was a break in the draining of the former lake for a period of time. If we look in Niagara Falls, we see that there is a very similar slope looking southward from the road where Walnut and Pine Avenues join to form Niagara Falls Blvd across from Packard Court and also as the boulevard passes through the side streets in the 70s in Lasalle.

I have noticed something really interesting about Ellicott Creek. Water from vast amounts of melting ice forms culverts in the ground beneath the ice as water flows away. This was no exception as what was to become Ellicott Creek was carved in the ground by sliding ice and then meltwater from the ice that formed the southern shore of Lake Tonawanda.

First of all, look at how the creek forms a nearly perfect hemisphere on a map. It is easy to picture bergs of ice sliding across what is now North Tonawanda, plowing up the ground, until coming to a halt when they melted enough to become unable to push the ground in front of them any further, and forming the culvert that would later become the creek from the meltwater.

On Young Street, around the intersection of Glenwood Ave., there is a small hill that the street goes over. If we look southward, the ground is sloped downward and gets lower away from the road. Now if we look on a map, we can see that this is where Ellicott Creek, just to the north, bends northwestward.

The reason becomes clear. Sliding ice, at the end of the last ice age, plowed up the ground as it slid southward along the slope, creating the dike that now prevents Ellicott Creek from continuing it's flow southward and to turn to the northwest instead. There are two similar small hills plowed up by ice, one at the intersection of Ellicott Creek Road and Ellicott Court and the other where Ellicott Creek joins Tonawanda Creek at the bridge joining Main Street in Tonawanda to Webster Street in North Tonawanda. The City of Tonawanda is not in the Netherlands but has a natural system of dikes built by sliding ice.

Further north, Tonawanda Creek may have begun as a parallel culvert further out and 8,000 years later, as Lake Tonawanda drained, was revived as one of the main channels of drainage from the lake's eastern extent. All of these features have, of course, been altered by this long time underwater before Lake Tonawanda drained.

Now, back to why the Niagara River first formed where it did at Buffalo-Fort Erie. There is a gap between the two features that I have described, the westward slope to the underlying rock strata that led icebergs from the melting and fracturing glacier at the end of the last ice age westward toward the area of what is now the falls and the general southward slope of the Niagara Escarpment leading to the sliding of bergs of ice from the melting glacier which formed the banks in Tonawanda which later formed the southern boundary of what was to become Lake Tonawanda. The main reason that the Niagara River formed where it did, at Buffalo-Fort Erie, is the shifting of an ancient escarpment by the pressure of the collision front of the Appalachian collision, as described in the posting on the geology blog, "All About The Appalachians".

In the posting "The Unique Islands Of The Upper Niagara River" on this blog, I explained how illogical the Tonawanda Channel of the Niagara River, to the east of Grand Island, was because it actually led the water away from it's destination, the falls. This could only mean, as I described there, that this channel must have formed first and that later surges of water from Lake Erie found a more direct route to the westward slope and the falls, forming what is now Grand Island in the process.

There is something about the physical geography of the Tonawanda Channel of the river and the City of Tonawanda that I cannot see has been pointed out yet. If we drive southwestward on River Road, the bluffs along the river begins about where the road intersects Wheeler Street. The ground is low up until that point.

Now look on a map of the area. You can see that the straight section of the river between North Tonawanda and Grand Island "points" directly at Tonawanda and that the intersection of River Road and Wheeler Street is just west of a straight line formed by this section of the river and continued into Tonawanda.

The valley around Two Mile Creek Road In Tonawanda was formed by glacial meltwater from what would become the southern shore of the lake flowing northward into the new Lake Tonawanda after the end of the ice age.

The curve in the Tonawanda Channel that I named the "Tonawanda Curve" is the nearly perfect right angle bend in the river from Strawberry Island to the south of Grand Island to Tonawanda Island, just off the shore of North Tonawanda. The Tonawanda Curve is divided approximately in half by the South Grand Island Bridges. This curve began with ice sliding around what must have been the vast amount of ice that was packed up against what is now the slope in Tonawanda described above which formed the southern shore of Lake Tonawanda.

But the Tonawanda Curve clearly was not formed by ice alone as we can see today, on either side of it around the area of the South Grand Island Bridges, the gradual V-shape to the countour of the land toward the river that is the signature of flowing water, not ice.

This is why I concluded that the Tonawanda Curve ended up being so perfect of a quadrant (we could also call it the "Tonawanda Quadrant") because there must have been a whirlpool motion in the draining Lake Tonawanda that formed a vector flow with the incoming water from Lake Erie and this is what eroded the Tonawanda Curve (or Quadrant) in the ground. However, the depth of the water in the curve, about 20 ft or 6m indicates that moving ice along this path was certainly a factor in it's formation also.