How Ice On The Rocks Reveals Our Destiny (Part I)

They bent the course of mighty rivers. They carved and scraped, forever leaving their imprint on the land we call home. But they did more than merely shape our local geography. They have guided us through the centuries.

And still do today.

The paths we take without thinking, the things we see every day, the very property upon which we build our homes, these all seem somewhat random events that accumulate over the course of our lives. But they, in fact, map the very destiny of our lives.

It supports our every move. It carries our weight without complaint. It provides the foundation on which we build our lives.

And yet, we take it for granted. Which is better than taking it for granite, which it is not. For those of us in the Greater Western New York Region, it’s more like shale. Or possibly limestone. It all depends on where you live. (Folks in Syracuse and Albany get the granite.)

The story of our bedrock makes for a perfect tale on a cold wintry day.

It could be worse. We could be living at the South Pole.

But to truly see this, we need to start at the very beginning…

No, really. If you go back far enough, our land of lake effect was located in what today is a land of permafrost – the South Pole.

Even so, maybe it wasn’t so frosty back then.

“It’s interesting that this whole region, if you go back starting about 600 million years ago or so, was all basically covered at various times with tropical seas,” says George McIntosh, Paleontologist, Rochester Museum and Science Center (Emeritus) who specializes in the geology and fossils of the Devonian Period. “Rochester, when we look at the rocks down near Mendon, that would have been about 400 million years ago, would have been about 30 to 35 degrees south of the equator. And if we were looking off to what is presently the East, we would have seen the beginnings of a very large mountain chain. And that mountain chain was caused by the collision of some micro continents into what is now the east coast of North America. Of course, all this is different, over time, because gradually what is presently east, was to our south back in the Devonian.”

We were totally under water: a shallow, but vast, inland sea of the pre-Pangean continent of Laurentia – the precursor to North America. This sea stretched from the Hudson Valley to the area that would eventually hold the Rocky Mountains and from modern Ontario to Alabama. In fact, this period of time – the Devonian Period within the Paleozoic Era – is called “The Age of the Fishes.”

“There’s a lot of interesting things to say about the Devonian as far as why did this mountain chain form,” says McIntosh. “To boil it all down, we had an ocean which was called the Iapetus. The Iapetus Ocean formed about 600 million years ago. It gradually expanded up until about 420-430 million years ago before it started contracting again.”

Within 10-20 million years – 380-390 million years ago for those counting – Laurentia collided first with Avalonia and then with Baltica, squeezing the Iapetus Ocean between them out of existence and forming the new continent of EurAmerica. In its wake, though, this collision – known as the Acadian orogeny – produced a large mountain range to the immediate east of Western New York.

“By the Devonian we had something called the Acadian Orogeny,” says McIntosh. “This was the final closing of that ocean that Iapetus Ocean and by this time, all the countries that we think of as the United Kingdom, Norway, Scandinavian countries, Germany, western Russia, all these things have collided with North America. So the Devonian is a very interesting time and we’re very fortunate to have these rocks in the fossil record here in Western New York.”

If you’re a student of geology, then you’re sure to know the one underlying trait of most of these early mountain ranges: you can’t see them anymore. Why not? Because Nature, in her infinite wisdom, saw to it that these earthen behemoths eroded themselves into oblivion. But that’s not to say they haven’t left their DNA strewn across the countryside. In fact, much of the study of Devonian geology takes place right here in the Greater Western New York region. This is where those Acadian mountains left their fingerprint – in the form of the fossils and rocks beneath our feet and jutting through the various “rock cities” among us.

In the case of the Acadians, water erosion from the west side of those mountains brought down silt and small pebbles into a gigantic delta known as the “Catskill Delta.” This was no ordinary delta formed by a single river (like, for example, the Mississippi Delta), but a huge complex of deltas formed by many small rivers. The Acadian mountains spent the remainder of the Devonian period bleeding themselves into the delta. As a result, the shoreline moved from the Hudson Valley to Western New York over this time.

As the sediment was deposited, the layers above crushed the layers below into various forms of rock. According to Nature’s Blog (“The Devonian Coast,” April 29, 2007), “…Western New York harbors one of the most extensive outcrops of Devonian rocks in North America.” It’s a tribute to the significance of Western New York geology that many types of rock from the Devonian period are named for the Western New York locales where they were first discovered. (Unfortunately, the period itself is named for the region in England where these rocks were first identified.) For example, that infamous Rochester Shale that so easily crumbled under the dry Niagara Falls represents a form of shale first discovered in the vicinity of Rochester.

The downside of all this geology, however, is the relative lack of biology. The less disturbed shallow sea in Pennsylvania found itself the graveyard of the exotic ferns and other plant life, while Western New York became a cemetery of marine life. The former meant Pennsylvania got most of the oil, although Western New York did get its fair share of natural gas. The latter meant Western New York received layers and layers of limestone, a key resource for, among other things, the processing of steel, and the source of many remains of the biological life that once inhabited our region.

“When it comes to the fossil record in Western New York, we’re almost totally marine fossils here,” says McIntosh. “We do have a little bit of terrestrial deposits coming in off the Catskill Delta, and that delta’s formed from this large mountain chain formed by the collision of all these little micro continents with North America. So if you’re there, look around the Mendon area. Everything we see is all shell water marine tropical sea faunas.”

But something happened that buried these fossils even deeper, and at the same time left the path to our destiny.

Next: How Ice On The Rocks Reveals Our Destiny (Part II) |