Northeast Ohio Through the Ages

Ron Blakey, Professor Emeritus of Geology at Northern Arizona University, has made a great series of maps which show the changes in the continental masses from 600 million years ago to the present. They are Mollweide, or “oval globe” projections, which show the entire Earth (but have significant distortion around the edges). The maps are centered on 0 degrees longitude. Professor Blakey constructed the maps circa 2008, using the best available geologic data.

I added a red dot to each map, in order to show the approximate location of the spot on Earth we now know as Northeast Ohio (and its motion across the face of Earth through geologic time). The placement of the dots was done after analyzing every relevant map of prehistoric Earth that I could find online. The first map is of Earth in the late Precambrian Era, 600 million years before present, and the last one is Earth in the present day. The increments between maps vary from 15 to 50 million years, except the last two which are 50 thousand years apart. Then, I put the dotted maps into an animation with the maps changing at the smallest possible interval.

So here goes 600 million years of our location’s change across the face of the Earth. Our “journey” begins far south of the equator, in the Antarctic region – 600 million years ago, what is now Ohio (and the rest of proto-North America) was located there on the ancient supercontinent of Pannotia. Be sure to keep your eye on the red dot!

That one went a bit too fast – 600 million years of movement in 4 seconds! So I recently made a new version for my presentation for the Cleveland Freethinkers’ last in-person meeting before the dreaded covid-19 accelerated (on March 1st). In this animation, the maps are at 4 second intervals and the time periods (in millions of years before the present) are marked at upper left. Once again, follow the red dots –

Another series of maps made by Professor Blakey are centered on what is now the North American landmass. The first map represents the NA landmass as it was 550 million years ago, and the last one shows it at the present day. I’ve put these into animations as well, once again with the red dots marking Northeast Ohio. One of the first things one might notice is that earlier on, “we” were under water for great lengths of time. Here is the “quickie” version:

…And here is the 4 second interval version, with date markers –

I hope you enjoyed the animations, and thank you Professor Blakey for the use of your maps!

Mark T.

 

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