Now, Arkansas and Ohio did not do their bit for Science since they chickened out at M4 and banned direct injection into the Precambrian. As well, we had the Virginia earthquake, which was very poorly covered by seismometers, but the later aftershocks showed a NE trend, and some association with a dammed lake.
Fortunately, we have other desperate states who are dying to prove my theories. If we are very lucky, they should go all the way to a New Madrid M7+, since they just can't give up all that money.
For the final bit, we digress into the whole story about the Precambrian under our feet. This a new story to most, since all the geological people ignore the deep structure, and when they plot earthquakes and faults, they stick to the shallows.
So, billions of years ago we had our Earth and oceans. The Galactic Seeders had come and gone, leaving a rich bacterial ecosystem. The amazing thing is that as the plates subducted with all the water, it cooked some rocks that were rich in silicates, and wanted to float like pond scum on the dark basalts. This scum became our continents, and North America was slowly built up by having huge island arc complexes, with their fresh silicates smashing up and pasting themselves like a big snowball rolling down the hill.
A billion years ago when this was in full swing, Toronto was under mountain ranges, up to the limits of rock strength. They were built up by sliding on huge megathrusts that extended in straight lines, NE to SW. You can see this type of linear range in the Rockies. The pressure eased off and these mountains slid back down. Eventually, erosion carved the landscape into something you see up in Cottage Country.