Monday, August 27, 2012

Glacial Erratics

With the help of a couple of neighbors, my friend Emma installed a small pond in her yard. She called me to ask if she could come pick up some rocks to surround it. If there’s one predominant element around here, it’s stone, so I said sure.

“They told me to ask if you have any erratic glacials,” she added. “Do you suppose that’s one of those questions a man doesn’t want to ask a woman directly?”

“Probably,” I told her, “but if you want to upset them, you can say I’m successfully self-medicating.”

She came out on a 100-degree day, and we walked the dry creek bed gathering roundish, flattish stones about the size the neighbor guys had specified. Most of the rocks were native limestone or sandstone, but we found a few red quartzite fragments. Lugging them up the bank was hot work.

Something like 600,000 years ago during the Pleistocene epoch, a glacier 500 feet thick covered this region. The force of the inexorable ice broke quartzite boulders off outcrops and carried them slowly south across 400 miles. Red or pink quartzite, colored by iron oxide, is the most common glacial erratic here. I’ve picked up red rocks in the timber, one by one, most of my life.

My father told me about the history of the red rocks when I was eight or nine. I pictured the Great Glacier as Bear Mother, descending from the north, pushing up earthworks before her, transplanting seeds and stones and nourishing the soil as she engulfed the land. Moving a few feet nearer to the sun each year, she carved river valleys, clawed streams between hillsides and opened the bones of the planet to the sky. Creeks are her granddaughters. Red rocks are her legacy.

Speckled red boulders appear at the sides of the roads each time the county clears the ditches. In small towns, they outline flowerbeds and encircle flagpoles. They stand like Herms to mark driveways. They hide beside creeks.

Emma lives just north of the terminal moraine. Most of the red rocks in her town have been tamed. A 24-ton quartzite boulder marks the city center. For centuries it lay in the river, revered as a prayer stone. Now it carries a plaque listing the city founders. The elemental history of ice and stone that preceded them is not mentioned.

Emma called again. “Now the guys think the stones are too small,” she said. “I told them they could go up a dry creek in a glaciated region and get their own.”

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