What’s older than dirt? Not you, though you may think you feel like it from time to time. The humble ocean quahog clam, sometimes washed ashore near Hatteras, can clap
What’s older than dirt? Not you, though you may think you feel like it from time to time. The humble ocean quahog clam, sometimes washed ashore near Hatteras, can clap around the marine depths for two centuries or more, besting our own longest lives by at least a hundred years. That clam doesn’t come close to soil from an age perspective. The oldest tree in North Carolina? The bald cypress spreading its wooden skirt in the Black River, more than 2,500 years old, is a baby compared to dirt.
Dirt eschews the bean-counting of years and decades and goes straight for millennia, for mega-anna (that’s a million years). The ground beneath your feet has been around, more or less, since before you, the quahog, and the bald cypress combined, and probably many times over.
Our soil begins with bedrock. You can find your bedrock, those slabs of stone beneath the dirt, if you dig deep enough. Weather wears bedrock from monoliths to stones, stones to pebbles, pebbles to grains. There’s life in this, too. Plants burrow their roots; ants and earthworms tunnel. Living things die and decompose, and the dirt begins to breathe with bacteria, fungi, tiny crawling things.
These are things we cannot see — either because they are too small or are underground — that move the nutrients around, feed our plants, help water flow, serve as the communication system for the great, wide, underground network of life.
Earth’s contours and environmental forces determine how much dirt we’ll keep, how deep our soil will grow. Mountaintops don’t get to keep much, if any, and the higher peaks reveal naked bedrock thrust from the earth. Rocky coasts reveal this, too. Valleys, on the other hand, gather dirt and the life within as if in big bowls.
The result is soil.
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Our soil is a fingerprint of place, a seemingly impossible gathering of forces that give rise to the world we hold familiar. On North Carolina rests more than 400 different types of soil, but we divide our state into the three types with which we are most familiar: the Cecil soil of the Piedmont, the sandy soils of the Sandhills, and the organic soils of the wetlands. Everything begins from the soil, and the soil keeps its toes dipped in its own beginnings.
The Piedmont’s Cecil soil, named for the Maryland county where it was first described, comes from igneous and metamorphic rocks, granite and feldspar hurled from inside the Earth that cooled into crystals back when the foothills were mountains, too. Rivers have carried pieces of the Piedmont to the Coastal Plain for thousands of years. There, the wetlands gather and distribute these pieces, turning them into new life. In the Sandhills, sedimentary rocks like siltstone and limestone molder into the dirt.
Glaciers brought their own nutrients, leaving footprints in our landscape. They sculpted Grandfather Mountain and melted into pools and bays in the Coastal Plain. This is young dirt, geologically speaking, only tens of thousands of years old.
We humans measure out our days in minutes and hours. We measure out our lifetimes in years and our families in generations. Dirt, however, works on geologic time. For some dirt, the clock started ticking millions of years ago. Geologic time moves slowly, but it does move. Humans may be able to build skyscrapers, gather sand for networks of roadways and parking garages, wipe out forests and erect cities, but the forces that work on geologic time can build entire mountain ranges, prairies, and oceans. They can hoist clouds into the sky and yank them back down. These forces determine our fates and possibilities: where we build our homes, the crops we grow, the grass we lie in to watch clouds on warm fall days. They determine which trees will shake and blow above us and which insects will creep below us.
What fallen wolves and deer, tyrannosaurs and unwanted peach pits, spears and mortars give rise to our lawns?
When we don’t fight our soil, we discover what bounty can come from living with it. The well-drained Sandhills bring forth tobacco; the wetlands cradle our floods; the Cecil spreads for rows of crops, an array of farms within a patchwork of pine, oak, and hickory.
These forces can be violent and full of fire, or they can be the gentle trickles of a melting block of ice. Both violence and gentleness hold enormous power: Both alter our human world in ways that seem irrevocable, but are unalterable to humans, who don’t have the luxury of millennia to do our own work, to make hay in the dirt that we have.
What tectonic shifts, what crumbled mountains do we squish between our toes? What fallen wolves and deer, tyrannosaurs and unwanted peach pits, spears and mortars, millennia of fallen leaves give rise to our lawns? How much of this dust-to-dust comes from ourselves and all we’ve loved, and how much of it will remain? It all will. It all will remain in the dirt.