Coal Black Heart Page 3
So it was entirely logical that Gesner picked a seaport called Parrsboro, on the Minas Basin, as the place to start a medical practice. He visited his patients by horse or on foot, travelling along a section of coastline where, twice a day, 100 billion tons of seawater—more than the combined flow of all the freshwater rivers in the world—pours in and out of a 200-million-year-old rift valley cradled between Nova Scotia and New Brunswick. The Mi’kmaqs, Nova Scotia’s first people, felt the Bay of Fundy a holy place. Gesner also discovered something transcendent in the way the surging water had stripped away millions of years of land, until the cliffs and shore shimmered with layers of geological time.
While visiting patients, Gesner made notes and gathered specimens. Before long, he was finding reason to edge along the Minas Basin all the way up Chignecto Bay to Joggins, to peruse the area’s mineral wealth. He read whatever geological books he could get his hands on, learning enough to publish his first work, Remarks on the Geology and Mineralogy of Nova Scotia, in 1836. “Let the great extent of the Coal fields of Nova Scotia,” he wrote in his overheated, biblical prose, “the beds of Iron Ore, Sandstone, Gypsum, Limestone; with every kind of material proper for building both the massive cathedral and the humble cottage, be considered.”
The book made enough of a splash that a year later Gesner was hired by the New Brunswick government to conduct a geological survey of its province. By then he was in his early forties. Yet he spent much of the next five years alone, except for his native guides, pushing his way up turbulent streams and over rugged mountains that had seldom been seen by white men. By the standards of the day his geological work was decent enough. The man just had no head for business. (“With no experience in practical mining, he was not able to make a realistic appraisal of the economic potential of the mineral occurrences he discovered,” geologist Loris Russell wrote in his entry about Gesner in the Dictionary of Canadian Biography. “Thus his enthusiasm saw in every galena vein or coal seam a lead mine or a coal field.”) By 1842 the man who would later usher in the modern petroleum industry was just about broke. In desperation, he opened a museum that included his vast collection of minerals, fossils and wildlife specimens. It failed. Gesner’s creditors took over his fabled collection, in lieu of payment.
All of which is to say that Gesner may have been overjoyed at the distraction of playing tour guide for an illustrious guest anxious to see the fossil cliffs of Joggins. Sir Charles Lyell—bony of visage and possessing the visionary’s thousand-mile stare—was on a side trip during his first visit to the United States and the British province of Canada. At almost forty-five, the most famous scientist in the English-speaking world was near the pinnacle of his career. Nine years earlier he had published the first edition of his seminal book, Principles of Geology: being an inquiry how far the former changes of the earths surface are referable to causes now in operation—which, more than any other work, had defined geology as a science.
By 1842, Lyell was smack dab in the middle of one of the great scientific/religious debates of the millennium: how old is the earth? Before the nineteenth century there was still relative unanimity in the Eastern, Christian world that God had created the world in six days. Then heretical new theories began to appear: that the earth was the result of a collision between a comet and the sun, or had condensed over eons from a cooling gas cloud. By the time Lyell arrived in Nova Scotia, the debate within the scientific community had hardened into two distinct camps. On one side were the “catastrophists,” who believed that earthquakes, volcanic eruptions, floods or other calamities were responsible for the formation of the world’s surface. On the other side stood the “uniformitarians,” of whose cause Lyell was the world’s leading proponent.
Lyell’s view can be boiled down to his famous dictum “The present is the key to the past.” Or, to put it another way, the earth’s crust changes now for the same reasons and at the same rate as it always has. And geological changes are the steady accumulation of minute changes over enormously long spans of time—not the result of some calamity sent by a righteous God. By 1842 this wasn’t the prevailing scientific view—far from it—so Lyell was forever searching for proof. Which brought him to Nova Scotia.
Lyell had another equally weighty question on his mind when he arrived in nearby Parrsboro to meet Gesner: what exactly was coal? Strange to think that on something so fundamental—the nature of the mineral fuelling the Industrial Revolution that was then transforming the world—there was no consensus. Many, including a young naturalist named Charles Darwin, thought the shiny black rock that extended for miles and miles must have formed in the only suitably vast location on the planet: under the sea. Two years earlier a Canadian geologist named William Logan had presented a paper that had knocked the scientific world for a loop; coal beds he had examined in South Wales were persistently underlaid with a layer of clay containing numerous fossil tree roots. In 1841 Logan had travelled to Pennsylvania and Joggins and found the same plant roots that were present in Wales. In his view, those were the roots of landlocked plant matter that was the source of the coal beds.
Lyell came to Joggins to see for himself. “I was particularly desirous, before I left England of examining the numerous fossil trees alluded to by Dr. Gesner as imbedded in an upright posture at many levels in the cliffs of the South Joggins,” he wrote in Travels in North America, his book about the journey.
I felt convinced that, if I could verify the account of which I had read, of the superposition of so many different tiers of trees, each representing forests which grew in succession on the same area, one above the other; and if I could prove at the same time their connection with seams of coal, it would go further than any facts yet recorded to confirm the theory that coal in general is derived from vegetables produced on the spots where the carbonaceous matter is now stored up in the earth.
Calder, who knows Joggins like a grizzled beat cop, understands precisely where to go: past the reddish-grey sandstone and the silt-stone and shale smoothed by the winds and waters of the Bay of Fundy Beneath the cliffs with their thick depths of clay, interspersed with boulders left during the retreat of the last ice sheet, thirteen thousand years ago. At one point, at least in theory, those layers of geological strata exposed in the cliffs were orderly and horizontal; older strata underneath, each newer layer being laid atop the older ones. Then something happened that knocked the world askew and folded the leading ends of the strata into the earth. When I turn to look at the cliffs, I see layers slanting downwards—at times almost on a 90-degree angle—from left to right. Which means that we’re now travelling through geological time as we move from west to east. “About a million years,” says Calder, agile as a mountain goat on the rocky surface. “Which, of course, is nothing in the overall scheme of things.”
Geological thinking has made quantum leaps since the era of Lyell and Gessner. For a layman like me the important thing is that Calder tells me I’m not hallucinating when I stare at a map of the world: Africa’s west coast does look like it could snuggle up against South America’s east. Slide everything together and you’d expect to hear a click as the continents lock near-perfectly into place. Geologists used to believe in continental drift, that the earth’s continents were slowly drifting across the surface of the globe. With time, that premise was supplanted by a new world view that goes by the snappy sounding title of “plate tectonics.” The continents—along with the ocean basins—are part of the earth’s crust, which is divided into some twenty segments called plates, which have nothing to do with continents. The African plate, for example, covers all of Africa, but most of its 62 million square kilometres are sea floor beneath the North and South Atlantic and Indian oceans. The North American plate—Nova Scotia’s home—is 76 million square kilometres running from the mid-Atlantic right to the west coast.
Wherever they lie, these plates are rock-solid, up to 150 kilometres thick under the continents while just 8 kilometres deep beneath the oceans. Beneath them is a softer
, hotter layer of solid rock that, because of its red-hot temperatures, can bend slowly like a bar of Turkish Delight. The plates of the earth’s crust float on this layer. It’s enough to give a fellow vertigo, the way these plates are forever changing positions and moving. No one’s absolutely sure why, but over the malleable layer the plates grow, shrink, combine and disappear, their number changing through time.
This means that, considered through the widest possible lens—eons rather than years, centuries or millennia—the earth isn’t some hunk of unchanging rock. Everything, even at this very moment, is moving and in flux. At a rate of just a few centimetres a year, mind you. Still, in a time frame where a million years is like nothing, big things happen: the earth’s crust migrates, oceans open and close, continents collide; land buckles, skids into the planet’s molten core and shoots miles into the skies forming mountains.
Some 275 million years ago, before dinosaurs or mammals roamed the land, an ocean of unimaginable size closed and the earth’s latest and greatest merger took place. Geologists christened the end result “Pangaea,” meaning “all earth” in Greek. In the middle of the new supercontinent, cheek by jowl with what would become North Africa and the Cornwall coast of England, lay Nova Scotia.
It’s a staggering notion: when Pangaea formed, Nova Scotia was on or near the equator, and continued to inch its way northward as the supercontinent slowly broke apart and the continents continued to assemble. In time, as the continents collided, mountain belts formed—and, eventually, small deep basins between them. This mosaic of interconnected mountains and basins extended from central Nova Scotia northward across the Gulf of St. Lawrence to the present-day shore of the Gaspé Peninsula, east to Newfoundland. The region, by then completely emerged from the sea, was crossed by northeasterly flowing rivers. The rivers carried gravel, sand and mud from the adjacent primordial mountains down into the luxuriant rainforest swamps and bogs flourishing across the tropical lowlands. As the climate warmed, vegetation formed, not just in present-day Nova Scotia but elsewhere in Pangaea’s spreading land mass. And ever so slowly, in the river valleys and freshwater lakes between the remains of those mountain ranges in what would become England and Wales, Pennsylvania, Virginia and Nova Scotia, coal formed.
What Calder seeks are the remnants of the vegetation that grew on the flood plains. The tectonic plates continued to grind, collide, recede and collapse, the continents to assemble. Rock bent into folds, or split, causing great slices of plate to rise and fall relative to each other. The Cumberland Basin, where Joggins lies, was one of the low-lying areas that settled between the faults. The exposed sediments we’re looking at are the 300-million-year-old wash from the rivers in the uplifted highlands to the west and south.
It doesn’t take Calder long to find what he’s after: a brownish column, maybe a yard around, suspended perpendicularly within the cliff face. All these hundreds of millions of years later, it’s still possible to make out elongated, diamond-shaped scars that span the trunk. Today, the tree’s only living relative is common club moss, which grows just a few centimetres high. In its heyday, that Lepidodendron, one of the most common types of lycopod, stretched thirty metres into the steamy prehistoric sky. Calder’s on a bit of a roll now, pointing out thin stems that indicate a once-thick undergrowth of calamites, ancient horsetails; running a finger along the remains of a cordaite, which had roots like today’s mangrove and metre-long leaves that resembled the amaryllis. Each remnant tells a similar story of the ancient crust of the earth sinking and sediment quickly—by geological standards—accumulating overtop.
Lyell and I have something in common. What he saw in 1842—Lepidodendrons suspended as if in aspic, lycopods haphazardly dotting the sedimentary rocks, calamites peeking out at weird angles—astounded him. “Just returned from an expedition of 3 days to the strait which divides Nova Scotia from New Brunswick,” he wrote to his sister after a Joggins visit similar to my own, “whither I went to see a forest of fossil coal—trees—the most wonderful phenomenon perhaps that I have seen, so upright do the trees stand, or so perpendicular to the strata, in the ever-wasting cliffs, every year a new crop being brought into view, as the violent tides of the Bay of Fundy and the intense frost of the winters here, combine to destroy, undermine, and sweep away the old one—trees twenty-five feet high and some have been seen of forty feet, piercing the beds of sandstone and terminating downwards in the same beds, usually coal.”
I have to tell you: it’s a humbling thing to look at the remains of a 300-million-year-old plant. The intricate, perfect design, for starters. Then there’s the notion I first encountered in Barbara Freese’s book Coal: A Human History, that when you look at an ancient fern you’re indirectly gazing upon prehistoric sunlight. All those ancient trees, ferns and mosses were sophisticated machines that captured solar energy, and converted it into chemical energy and carbon that stayed stored within their cells until they decayed, burned or got eaten. Usually, when plant material dies, it decomposes more rapidly than it accumulates. Peat, the precursor to coal, forms when the reverse is true—when the wetland has a waterlogged surface with little access to oxygen, and this protects the plant matter from bacteria, fungi and other organisms that cause decomposition.
Whether or not peat will form depends mostly on climate and geology. Precipitation has to exceed evaporation. The buildup of plant matter has to keep pace with the subsidence of the earth’s surface, so sedimentary deposits or rising water levels don’t overwhelm the peat. Let’s assume optimum conditions. Beneath the ever-deepening layers of sand, silt and mud, most of the peat moisture is squeezed out. More heat and pressure furthers the transformation, first into lignite, a soft, brownish-black coal with a low carbon content, then black or bituminous coal, the type found in Nova Scotia and in most of the coal-bearing areas on the planet. A mineral that fuels economies, launches kingdoms and revolutionizes worlds.
Coal wasn’t the only rock formed in the Carboniferous—the name given by scientists to the period running from 360 million to 280 million years ago—world. Basins were subsiding, infiltrated by upland streams that deposited their coarse sand and gravel loads, covered by rising seas that eventually retreated, leaving coastal plains that were again colonized by peat-forming vegetation. The pattern—coal seams, flood-plain mudstones, lake or marine lime-stones and riverbed sandstones—is visible in outcrops around the world, and is thought to be linked to the rising and falling sea level as the ice caps of the South Pole melted and grew when the climate shifted. Nowhere, though, can match Joggins as a time-lapsed snapshot taken as the world’s great coalfields were being formed.
No wonder Joggins was so deeply embedded in Lyell’s thinking from that moment on. In 1852 he returned with another illustrious Nova Scotian scientist in tow. They had met a decade earlier, when Lyell made a brief stop before his trip to Joggins. In New Glasgow he dined at Mount Rundell, met the local mucky-mucks and paid a visit to a young man with a good fossil collection. “He looked over my specimens with appreciation,” John William Dawson wrote in his memoirs, “and listened with interest to what I could tell him of the geology of the beds in which they occurred.” Dawson, twenty-two, devoutly Christian, fluent in Latin and Greek and with a working knowledge of Hebrew, was freshly back from Edinburgh, Scotland, after his university studies had been interrupted by a family financial setback. At that point his startlingly varied career—geologist, paleontologist, author, publisher, politician, educational visionary, university president—was just beginning. His life-altering epiphany, on the other hand, had already occurred. “It happened, when I was a mere schoolboy,” Dawson wrote, “that an excavation in a bank not far from the schoolhouse exposed a bed of fine clay-shale which some of the boys discovered to be available for the manufacture of home-made slate pencils.”
Dawson and his classmates used to amuse themselves by digging out flakes of the stone and cutting them into pencils with their pocket knives. One day Dawson was surprised to discover that one of the fl
akes “had on it what seemed to be a delicate tracing in black, of a leaf like that of a fern.” The riddle—real leaves or not, and if real, how did they come to be in the stone?—preoccupied his mind. Eventually his father sent him to the principal of a local grammar school, the astute Scotsman Thomas McCulloch. He “received me kindly, and assured me that the impressions were real leaves imbedded in the stone when it was being formed.” And Dawson’s life, quite simply, was never the same again.
He read everything he could get his hands on about geology and natural history. He began collecting the minerals, shells and fossils that he found in the Pictou County countryside and as far away as the petrified forest of Joggins. He expanded his collection by exchanging specimens with Gesner and other Nova Scotia geologists. At the University of Edinburgh he took courses in geology, taxidermy and the preparation of thin sections of fossil animals and plants for the microscope. Meeting Lyell was another turning point; a friendship blossomed. Afterwards, Dawson went back to university and became British North America’s first trained geologist.