Glimpses of a Mass Extinction in Modern-Day Western New York
I began veering into the rumble strip somewhere near Binghamton. Traffic engineers are lucky that few people know what’s on the side of the highway, but I had been spending time in the dangerous company of geologists—and now I was a rubbernecking menace. This time, I was slack-jawed and lurching on I-86, disoriented by a road cut that placed me somewhere at the bottom of an ancestral ocean three hundred and eighty-five million years ago.
I had already had quite the trip. A short drive on the highway that morning had dropped me from the airless, snow-capped peaks that once towered over New York City, down through a sprawling delta in the tropics where the planet’s first trees rose from the edge of the sea. But the Hudson Valley roughly marked land’s end, and, by now, I had pushed off this secret coastline to head west, and offshore. The red earth that earlier bracketed the highway—rumors of ancient rivers on land—now gave way to gray, banded rocks filled with seashells, where stacks of seafloor piled up, millennia-thick.
“The farther west you go in New York, it’s all marine fossils,” a paleontologist told me before I left. “New York would have been facing into a great continental sea. All the way out to Ohio, it’s all marine.”
This upstate ocean poked out from under farmland, and crumbled from rock walls behind gas stations. In the Devonian period—hundreds of millions of years ago—it was filled with sea lilies, sea scorpions, armor-plated monster fish, forests of glass sponges, and patch reefs of strange corals. At night, these reefs were cast in shimmering chiaroscuro, inviting moonlit patrols of sharks and coelacanths. Where the water met land in eastern New York, dawn revealed fish hauling ashore on nervous day trips—slimy, gasping astronauts under a withering sun.
In the ages since, the tropical inland sea drained away, the continents merged and rifted, and the seafloor turned to stone. As fish conquered the land at last, the ocean was buried and forgotten. Era stretched to eon, and, where there were once croaks of stranded lungfish, sail-backed dimetrodons now groaned confidently across an arid supercontinent. A hundred million years later, these groans gave way to the wails of dinosaurs. And a hundred million years after that—still more dinosaurs. But, all along, in New York, the old seabed lay buried in darkness. Another hundred million years passed.
Then, not long ago, continents of ice planed off the state, removing these untold histories. As the ice retreated, meltwater carved gorges through the ancient seafloor, and sunshine fell on its depths once more. Humans arrived. The elephantine fanfare of the Ice Age went silent, and the highway department chiselled out a few more crags with dynamite. Now shells of a strange vintage tumble from the side of the road across the entire state.
This is the surprising inheritance of New York, where, from Albany to Buffalo—and just beneath the thin, photosynthetic rind of our world—an alien ocean planet, still groping toward the land, is frozen in stone.
In the eastern half of the state, and especially in the Catskills, the pulsing shoreline of this tropical sea wafts back and forth over millions of years—a collage of floodplains, lagoons, deltas, estuaries, and beaches, arrested in the strata and invisible to all but stratigraphers. Three hundred eighty-five million years ago, the first trees in the history of life sprouted along this forgotten coast. One day, after a storm, some of these coastal trees were buried by floodwaters, cast in sandstone, and packaged for safe passage to the far future. A century ago, these fossil tree stumps were uncovered by construction workers in Gilboa, New York, who were quarrying stone for a dam that would eventually drown the Catskills town. Now the village of Gilboa is under a hundred and twenty feet of New York City tap water, and the planet’s first forest is behind the high-security cordon of the New York City Department of Environmental Protection. But branches of these first trees, some of which washed out to sea, can be found elsewhere in the state: behind a Binghamton strip mall, in a retaining wall next to a Starbucks drive-through, I found the ageless twigs embedded in boulders that had been quarried nearby.
The rise of these plants and their invasion of the land ended more than four billion years of continental desolation. The trees invited fish to come ashore and consider becoming tyrannosaurs, humans, and hummingbirds. But this life style, severed from the sea, was still a daydream: the pioneering fish of the Devonian, and the halfway world they inhabited, claim more distance from the beginning of the age of the dinosaurs than the dinosaurs do from our own time.
This onshore world, then, was still a novelty—an absurd one even, for what had always been an ocean planet. And, in the Devonian, it was still provisional. I was interested in that much older, more confident planet long rioting under the surf.
After a few more hours of erratic driving, I dove in around Ithaca.
“It’s paradise,” the Cornell paleontologist Warren Allmon, who agreed to be my dive instructor for the day, said. Allmon killed his engine at the end of a dirt road overlooking Ithaca’s Lake Cayuga.
“I mean, paleontologically, it’s just paradise.”
Allmon directs the Paleontological Research Institution in Ithaca, whose Museum of the Earth houses what it can of the spoils of upstate New York. It wasn’t hard to convince him to spend the day cracking open local rocks, so we hiked down to a stream in the woods that was slowly excavating the ancient seafloor. A large, incongruous block of limestone diverted the stream, and I asked Allmon where it came from. He pointed to an imaginary spot somewhere in the treetops. Compared to the rocks at our feet, this errant stone was still millions of years in the future. And, in the other direction, buried twenty-five hundred feet below us, were giant seams of sea salt from an ancient Persian Gulf millions of years in the past. But, before us, entombed in the banks of the stream, was a mucky tropical sea bottom, where thin, frangible layers of gray siltstone marked the passage of centuries.
“Geologists take it for granted that rock equals time,” Allmon said. “I don’t know of another experience that we all have in our daily lives where a solid substance represents time.”
He took out his rock hammer and unsentimentally laid into the bluffs, splintering the rock into jagged slabs. The rocks revealed a spattering of tiny seashells, swirling burrows, and a hash of body armor and compound eyes. The seashells once housed marine worms called brachiopods, but the burrows were a mystery. As for the armor and eyes, they belonged to trilobites—vaguely technological sea bugs that thrived in the ocean for almost three hundred million years. Before their eternity in the stone, these eyes caught glints of starlight dimly streaming through the murk.
“If you were snorkeling here, there would be really low visibility, not many waves, a storm or two every so often,” Allmon said, gazing out at the woods. “Kind of like the Gulf Coast without a breeze, that kind of thing. I can’t conceive that this was more than a hundred feet deep.”
The mud in these turbid waters was delivered from an epic mountain range in the east, which was then hemorrhaging sediment under the assault of tropical storms and monsoon rains. The Yankee Himalayas were shoved into the sky by eastern New England, long part of an island chain that had rifted off an Antarctic supercontinent and traversed a southern ocean—and which was now crashing into North America. Disoriented by this jumbled geography, I was gently reassured, “We’re still talking about a world in which Pangaea had yet to come together.”
In the course of millions of years, as these mountains wore down, the dissolved rock flushed into the rivers and floodplains of an Appalachian Bangladesh, and on out into the ocean, where it settled on a sinking seafloor, piling up here in the middle of the state, almost two miles thick. Down the road, in Trumansburg, at Taughannock Falls, this tremendous pile of time is visible, if only in part, as a two-hundred-foot wall of piled-up seafloor that frames a wisp of falling white water. Just downstream, at the more modest Lower Taughannock Falls, this giant stack of gray is interrupted by a startling platform of limestone. The dramatic change roughly marks the Taghanic Event—a mass extinction that razed corals, brachiopods, and squid-like creatures stuffed in elegant shells all over the world. It was one of almost twenty global mass extinctions in the history of complex life, a list that includes five cataclysmic outliers, when the planet nearly died, and one that might someday include us. The Taghanic Event was an ancient global-warming disaster, complete with rising seas and oxygen-starved oceans. This is how most mass extinctions unfold. It didn’t quite achieve the peerless horror of the worst five Armageddons in Earth history, but, elsewhere in New York, the rocks do record one such doomsday.
As you drive farther west, and farther offshore, the shallow seabeds of Ithaca grade to outcrops of deep-water black shale that glisten with natural gas. The rocks are greasy with the organic residue of buried sea life, and are now fracked with great enthusiasm. This life sank to the bottom of putrid, anoxic seas that pulsed throughout the Devonian period, burying massive amounts of organic carbon, in wave after wave of extinction. Where West Virginians dig up forests from the Carboniferous period as coal, and Permian sea life spouts from Texas oil derricks, much of the natural gas we frack today comes from the smothering seas of the Devonian extinctions. Spying some of these ominous black shales rising from the side of I-90, and knowing that there was boundary in the rocks nearby marking one of the worst mass extinctions of all time, I pulled off at the nearest exit, walked into the geology department of SUNY Fredonia and poked around for help. I ended up walking into the office of Gary Lash.
In 2011, Lash was named one of Foreign Policy’s “Top 100 Global Thinkers,” earning the nod after estimating that the local Marcellus Shale was the largest unconventional natural gas reserve in the world—a discovery that toppled the board game of global energy geopolitics. The first commercial gas well in the United States, drilled into the marine shales of the Devonian in 1826, isn’t far from Lash’s office. It’s in front of a dentist’s office, marked by a plaque on a rock. A little further down the road, these rocks crop out along Lake Erie, and roughly mark the culmination of an apocalypse three hundred seventy-five million years ago.
The great Devonian mass extinction remains something of a mystery. There were oxygen-starved oceans, fueled by an explosion of massive algae blooms—perhaps even driven by runoff from the land, as the emerging world of trees carried out their massive geoengineering project, greening the continents. Other research adds invasive species spread by surging seas, preposterous volcanoes and extreme climate change to the chaos for good measure. Whatever form this destroyer took, it laid waste to 99.99 per cent of the largest reef systems the world has ever known—the so-called “megareefs” of the Devonian, ten times more extensive than our own. Trilobites, tentacled drifters, fish wrapped in heavy armor—nothing was spared. Lash had his own grisly ideas about the disaster, one involving catastrophic methane releases from the deep and intense global warming.
“It was just a bunch of bad things all converging at once,” he said.
He photocopied a map of the area and pointed me to the extinction exposure in neighboring Dunkirk, New York, on the shores of Lake Erie.
“I wish I didn’t have classes, or I’d go down there with you,” he said.
As I was leaving, he offered some mysterious parting words.
“Have you ever huffed some of the shale?”
He started laughing."
“When you get don there, take a piece of the black shale and break it open. Take a hit of that.”
I followed Lash’s directions and arrived where New York ends, at Lake Erie. It was an odd place. I parked in a field under a coal-fired power plant and strolled onto a sandy beach strewn with Russian zebra mussels and plastic. The beach was framed by hulking blocks of black shale, glimmering with a yellow, sulfurous sheen. Here’s the end, I thought, noting the change in strata from green-gray to deep black, marking the final extinction pulse of the Devonian cataclysm. I picked off a flake of black shale, as directed, and cracked it open in my fingers. It smelled like gasoline.
On the drive up to Ithaca, something was going awry. Rolling hills bursting with green slowly dulled to an unearthly pallor, and road signs normally reserved for traffic alerts now flashed updates about outer space: “SOLAR ECLIPSE TODAY.” I stole a look at the waning sun through my windshield, at some ambiguous risk to my retinae. The missing piece of star was carved out by the same moon that once careened around a Devonian world, its ancient tug evident in the regular layering of seafloor in outcrops along the highway. In the Devonian the moon was ten thousand miles closer, and summoned surging tides that flung fish onto tidal flats, daring them to walk. As a result, the sun rose and fell four hundred times a year, and corals—nestled in lagoons and fringing barrier reefs—registered this ancient astronomy in their skeletons. In Ithaca, Allmon showed me a head of coral from outside Rochester with yearly packages of daily growth lines numbering four hundred. ‘What was that day like?’ I wondered, picking out a line. These reefs were annihilated by mass extinction, and it is believed that our reefs will also mostly die off in the second half of this century.
What came after the Devonian was everything: fish ultimately emerged onto a landscape already furnished by plants, and some of them even spread their fins and learned to fly. But what will come after us? In a hundred million years, the same cratered stone will still be tethered to our planet by space-time, hurling around it at impossible speed. Its moonlight will still shine on the creatures below, but whose eyes will gaze back?
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