So I’m bit puzzled trying to figure out exactly where the eastern end of the Niagara Escarpment goes.
Of course, Niagara Falls flows over the Escarpment, but erosion from the Falls means it’s actually a few miles north on either bank. It’s easily followed into Lockport, where the Erie Canal descends from above the Escarpment to below.
But somewhere between Lockport and Rochester the Escarpment becomes indistinct at best. I should think it would have to remain south of the Canal because there are no more locks on the Canal until you reach Pittsford. Yet the falls of the Genesee River are said to have been formed due to the Escarpment, and they’re well north of the Canal. There’s a clear escarpment along Ridgeway Avenue in Greece and Rochester, just south of the Ridge Road, but if that’s the Niagara, the Canal must have crossed it at some point.
So where does the Escarpment go between Lockport and Rochester?
Speaking of the Ridge Road, I’ve read in multiple places that the ridge which it follows was formed by the Niagara Escarpment, but that’s impossible for the reasons I stated above; the Ridge is well north of the Canal and north even of the visible Escarpments in Lockport and Rochester. So how did the Ridge form, if not by the Escarpment?
Powers &8^]
I live in this area and I’ve driven Ridge Road many times. Actually, it seems to me that the ridge peters out just to the west of Lockport, although that’s subject to debate.
The soil patterns between the Escarpment and Lake Ontario seem to suggest that the landform is glacial. The same glacial forces which dug Lake Ontario and the Escarpment during the Ice Age also formed the ridge. That ridge is not unique to Western New York…there’s a similar ridge north of Toronto also formed by glacial forces.
Yes, the glacial origin seems to be the most likely explanation. I’ll have to correct Wikipedia on that.
Still leaves the question of where exactly the escarpment goes between Lockport and Rochester, though. Anyone have any ideas regarding sources I could use?
Powers &8^]
I can’t guarantee it’ll answer your exact question since I don’t have the New York one, but the Roadside Geology books usually do a pretty good job of describing big geological features like this and orienting them relative to cities and roads. They also do a great job of providing accurate and interesting but not too technical information. Here’s the New York one: http://www.amazon.com/Roadside-Geology-New-York/dp/0878421807
Many thanks! That could be quite useful. I like the cutaway view of Niagara Falls on the front cover, too; that bodes well for what might be inside. =)
Powers &8^]
The guy listed on this page would probably have the answer for you. I remember seeing a very long, very boring (from a ten-year-old POV) film strip here that went into the geography of the Falls, the Escarpment and Western New York in detail. I plan to take my homeschooler here soon. Very good resource.
Yes. If you look at a map of the Eastern North American continent, you can draw a line from Niagara Falls north and west into Canada, then west and south into Wisconsin, where it peters out around Oshkosh. It’s approximately a semicircle, and represents the edge of an ancient, shallow lake in a saucer shape, with the northern edge of the saucer tilted up. Lower Michigan state lies entirely in the bowl, about the center.
From googling into the NYGIS, i downloaded the “finger lakes bedrock sheet”.
I’m no expert, but it looks like it goes east until ending just south of Lake Oneida
the book (on page 26) has it going south of the canal until crossing to the northern side between Spencerport and I-490
(page 7)Ridge Road is the former shoreline of Lake Iroquois, a precursor to lake Ontario.
Edwin Raisz’s hand-drawn geomorphology map of the US shows the main ridgeline continuing just south of the canal, then petering out right before the Genesee River near Rochester; but it shows a less prominent, secondary ridgeline north of the canal as well, paralleling the first (in other words, the canal is on a sort of intermediate step). From the above posts, I take it that Ridge Road follows the secondary ridgeline.
I can’t thank you guys enough for this great information. That issue of Rochester History in particular was very straightforward and clear. I’m surprised that I couldn’t find this information on my own, given how well-established it apparently is.
Powers &8^]
It’s also visible as a ridge a few miles southeast of the city of Green Bay; there, it’s referred to as “Scray’s Hill”. All of Green Bay’s TV stations have their transmission towers there, as it’s the highest point in the area. (I grew up with a view of the ridge outside my bedroom window.)