Wednesday, March 17, 2010

A Vanished Sea

Three hundred million years ago is a long time ago. A long, long time ago. Living here in the Midwest, I don’t often have reminders that our planet has been around that long. The geological features that form my daily landscape are not that old. The Great Lakes, according to most experts, were formed about 13,000 years ago following the last Ice Age. As the ice retreated, it left the bodies of water that we know as the Great Lakes.

I was out west this past weekend, in Nevada, where the landscape is much more dramatic and reminders of the age and history of our planet are all around. I visited Valley of Fire State Park, about an hour outside of Las Vegas, where the red sandstone that gives the park its name is an amazing – and very dry - site.

As you gaze out over the landscape from the park’s Visitors Center, you are reminded that millions of years ago there was a vast inland sea here. You can imagine it. Mountains and rocks rim a valley where the shallow sea contained all kinds of ancient plant and animal life, remnants of which still remain.

I came back to my own inland sea, and gazed out at it, trying to imagine what this land will look like if the water retreats and leaves behind only the dry, flat bottom. Will that happen? I could prophesize that it will, if we don’t take care of our lakes, but the truth may be that even if we do, they will vanish in a hundred million years or so anyway. Change is constant on this planet.

Still, like the arguments about climate change, we have to ask what the effect of our modern civilization is on this change. Three hundred million years ago when the Nevada inland sea was warm and teeming with life, there were no human beings to accelerate the demise of that sea. Maybe that's why it survived as long as it did.

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