Coal Black Heart Read Online Free PDF

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 barof 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