The Rocks and Minerals of Niagara Falls
Since we are discussing Niagara Falls geology, it’s also imperative to note the type of rocks that are in the area, some of which are constantly eroding do to the process of cavitation. Interestingly enough, at roughly 400 million years ago, tropical saltwater seas actually covered the Niagara region. Ancient specimens and fossils found in the area which are found under our oceans today point to this being the case. After the ancient river bed was blasted out by the relatively new Niagara River, rock layers that had been laid down as sediments of mud, sand, clay, and shells under that ancient sea were exposed. Then they became sedimentary rock from all the pressure.
What can be seen today, looking toward the American side, is perhaps the largest display of this type of rock, known as a Silurian exposure. Silurian simply means from the ancient geological period known as the Palezoic Era. Shale, sandstone, and limestone are all in the area. The stunning emerald waters of the Niagara River are also the result of erosion causing an abundant supply of minerals to be displaced in the water. Approximately 60 tons of these dissolved minerals come sweeping over the Falls every minute. The green color is made from "rock flour" which are dissolved salts from finely grained rock believed to come from the limestone bed of rock.
Image courtesy of commons.wikimedia.org
Now that you are well versed in Niagara Falls geology, you will better appreciate how many thousands of years it took to form that awe-inspiring site. It is in witnessing these stunning geological features that we humans can be humbled by our fledgling and relatively insignificant presence on a planet that flourished with natural beauty long before we ever came into being. But if you go there today, you will also see our attempts at holding back the power of erosion with man-made structures, largely in part to protect power plants that service many of our modern needs.