Sand is the very image of abundance, our standard rule-of-thumb metric for imagining the number of stars in the universe or molecules in a drop of water.
To think of sand is also to think of time. Sand is blown to cover the grandest monuments humankind has created, and when it flows in the hourglass, temporal enormity quickly trickles down to nothing.
Some of the oldest sand on earth is in a place named for it: the so-called “Sand Counties” of south-central Wisconsin, where sand was deposited at the bottom of an inland sea five hundred million years ago, when North America was part of a then newly formed supercontinent that we now refer to as Laurentia.
The sand rolled in the currents and tumbled in the tides of those clement, shallow seas for millions and millions of years. Slowly, it was refined into a fine sediment of tiny, uniformly sized, beautifully round grains.
Half a billion years later, the climate had cooled, the seas had receded; a vast ice sheet crept down the continent from the Canadian shield, depositing a layer of “drift”—glacial tillage, consisting of material plowed up, transported, and deposited by advancing and retreating ice.
Throughout much of the northern Midwest, the sand now lies buried beneath the glacial drift. But the area of the Sand Counties—in a region stretching from central Wisconsin into Iowa and Illinois today—was never touched by the glaciers. Today a soft corduroy of low hills and ancient seabed blankets the region, which is also called “the Driftless Area,” as it lacks the deep, level bed of drift—now a rich soil – which makes the rest of the Midwest a flatland fit for corn and beans.
Cool ridge-slopes in the Driftless Area harbor a flora and fauna—mosses and liverworts, even a tiny snail—that are surviving remnants of the last ice age.
There’s a lovely irony of magnitude at work in the Driftless Area: a dialectic of continental ice masses, a bygone era of megafauna like the mastodon and the giant sloth, remembered now through minuscule creatures secreted in an unassuming midwestern landscape.
Not long after the era of ice and megafauna (reckoned geologically), the forester and ecologist Aldo Leopold bought himself a farm on the edge of the Driftless Area in south-central Wisconsin.
Born in Iowa, Leopold had been a forester for the US government in Arizona and New Mexico; later, he became a professor at the University of Wisconsin, bought his place in Sauk County, and began compiling the essays and observations that were published as A Sand County Almanac after his death. In that book, Leopold distilled his love of wild places and professed the virtue of the abiding qualities of intact ecosystems, which can thrive for millennia without human interference.
In the fullness of deep time, living matter from such ancient ecosystems coalesced over aeons into shale beds harboring oil and natural gas. In recent years, the controversial process of hydraulic fracturing or “fracking” has opened up these deep shales to human exploitation—and the lands above, and the people who live there, to a panoply of hazards, from earthquakes to hazardous waste.
There are no oil shales in Wisconsin. But the ancient sands of the Driftless Area have a role in fracking: with their small, round grains, they make an ideal “proppant” medium which, poured into wellheads, holds open fissures in the rock for gas and oil extraction.
So called “frac sand” mines are a fixture in south-central Wisconsin today. And they, too, have their environmental consequences: the mines scar the fields and farmlands; the silky, round-grained sand is so fine that it can billow into the air.
Driven by short-sighted impulses, our machines disturb, uplift, and redistribute sediments laid down over the deep, cycling history of life so savored by Aldo Leopold. What took millions of years to nurture is now undone in a geologic flash.
All of this recalls Leopold’s book, a touchstone of the American conservation movement, in which he articulates what has come to be called the Land Ethic:
“A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community,” he writes. “It is wrong when it tends otherwise.”
Matthew Battles is associate director of metaLAB
, a creative research agency based at Harvard's Berkman Center for Internet and Society. He is the author of several books, the most recent of which is Palimpsest: A History of the Written Word