Long before our magazine Escarpment Views was created, Mike got a fascinating book about the Niagara Escarpment called Guide to the Geology of the Niagara Escarpment, written by Dr. Walter M. Tovell and published by The Niagara Escarpment Commission in 1992. Remember that the Niagara Escarpment was designated a UNESCO Biosphere Reserve in 1990. It seems to be intended to help with teaching the science of the Escarpment, and it continues to be worth diving into. I don’t know if it’s still in print. Likely not, as I find that many books fade away far before they should. Here is Tovell’s interesting summary of the theories for the origin of the Niagara Escarpment:
“The Niagara Escarpment consists of Ordovician and Silurian rocks formed from sediments deposited in ancient seas between 445 and 420 million years ago. It is also known that between 23,000 and 12,000 years ago the escarpment was covered with 2-3 km of ice for the last time. Many people used to consider that the Niagara Escarpment was a fault. Such is not the case – it was formed by erosion and existed prior to glaciation. Further evidence indicates that the Niagara Escarpment came into existence during the long preglacial interval and that continuous erosion must have been the cause of its formation.
“When the land that is now southern Ontario emerged from the seas of the Paleozoic Era at least 245 million or more years ago, drainage networks developed and began the task of eroding the land by removing immense quantities of rocky materials. In this way the Niagara Escarpment developed because of the different hardness of the rock formations. During the development of the escarpment, outliers were formed. These were destroyed by further erosion, and with their destruction the escarpment retreated. Because of erosion the escarpment may have migrated southwestward over much of southern Ontario.”
So while the Escarpment may look like part of the earth rose up sharply, this explanation has it that erosion wore away the softer materials, leaving the harder rock exposed. Since this was published in 1992, it would be interesting to find out if this still the current theory. Anyone know anything more?