Название | A Wilder Time |
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Автор произведения | William E. Glassley |
Жанр | География |
Серия | |
Издательство | География |
Год выпуска | 0 |
isbn | 9781942658351 |
OVER TEN THOUSAND YEARS AGO, during the last Ice Age, the landscape I stood on had been buried under thousands of feet of ice. Every valley and ridge that could be seen, every hillock and defile had been the floor to that ponderously migrating sea of frozen water. This was a young, inherited landscape, shaped by the grinding ice of that ancient time. As the Ice Age melted away and exposed the bedrock, the sculpted land provided footholds for pioneer plants. Season after season, as plant life slowly but incessantly blossomed, withered, and died, plant remnants found anchor in ice-wedged cracks, lichen attached to bare rock, and dust settled into pockets and irregularities, nurturing an unimagined future that included our little camp.
As land plants took hold, Neanderthals and emergent Cro-Magnons may have walked over the hillocks and ridges there, searching for food and exploring. But it’s unlikely they settled anywhere in that harsh place—the world farther south and across warmer seas was more hospitable. Even so, it was difficult, when gazing at the ice walls, not to imagine early humans skirting along them.
It was a panorama that defied comprehension. There was nothing familiar there. The absence of trees, of houses or streets, of cars or people, the lack of movement of any kind—all contributed to a sense that I was walking alone in an alien world, not of Earth, but of some planet where forces and processes played out their dramas according to different rules.
The longer I stood there, the more intense was the conflict between the experience of the place and what I had remembered of Greenland. As before, a deep sense of serenity permeated everything that was present—there was a unity of actions and substances, an uninterrupted unfolding that shaped and colored everything. And yet, something felt askew.
Then a lone bumblebee buzzed past my ear, soared off into the valley, and disappeared, and it became clear what that disjointed experience meant. Despite the dynamism of that world, it was utterly and deeply still. I suddenly realized that it was the silence of the place that I had forgotten.
The gentlest breeze brushed my face, but there was nothing to hear. The distant rivers flowed, their shimmering surfaces vaguely vibrating with motion, but no sound emanated from them. I turned in every direction, listening for anything, but there was nothing.
What could be heard was the nature of the primordial world. Four billion years ago, on the barren surface of Earth’s first land, with the exception of a rare roaring gale or exploding volcano, there would have been no sound. Similarly, in the ocean or the air, silence would have persisted, except where seas lapped onto continental margins and waves washed over eroding sands. In fact, for most of Earth’s history, silence ruled.
With the emergence of animals more than 600 million years ago, that silent condition was slowly modified. Fishes clicked, bees hummed, dinosaurs roared and bellowed, birds chirped, horses whinnied, and, eventually, humans spoke and sang. The buzz on the surface that life brought to the world grew in complexity and volume, culminating in the constant roar of our cities.
A shout or a scream where I stood would have been swallowed in the expanse of wildness. That world was ancient beyond measure, holding on to the nearly vanished character of what once was, existing as a remnant enclave, speaking in its silence the song of our origins. What was present in that vast, unimaginable panorama was an invitation to embrace anything and everything.
I stayed at the promontory for as long as I could, struggling to find a way to silence my mind. But my hands and feet were aching from the cold, and the exhaustion of the past day was beginning to take hold. Wrapped in the cloak of wilderness, I walked back to camp, trying to do nothing but listen.
THE NEXT MORNING, BEFORE I WALKED to the cook tent, I went down to the fjord to hear the sound of water lapping on the shore, seeking a connection to the world we had left behind. There was no wind; the surface of the water glistened like glass. The slight swell that slowly undulated that finger of sea did not stir a single grain of sand. What sound existed came from me.
I walked to the kitchen tent and joined Kai and John for coffee and our first breakfast for that field season. We explored the food crates, looking for appealing items, each grabbing his own unique mix of canned and smoked fishes, muesli, oats, powdered milk, bread, sugar, and jam. As we ate and planned the day, I kept to myself the walk I had taken. It wasn’t the time to let them know I liked to wander off alone.
WE WERE THERE TO OBSERVE, and to collect samples of anything that would provide evidence of the terrain’s history—stretched crystals, folded and distorted rock layers, and any other indicators of tectonic movements. Noting on a map the places where each observation was made and where the samples were collected would allow us to piece together a tentative story while in the field. The samples we collected would be shipped back to our laboratories, where we could later assemble other facets of the history—how hot the rocks had been and how deeply buried they were when the deformation had occurred. The field observations combined with the results from the laboratory would provide the factual framework for the history we would write of what had happened thousands of millions of years ago.
The vanished mountains we envisioned were simple possibilities, tentative interpretations of passages written subtly in the obtuse patterns and features of Greenland’s rocks. The patterns match those seen in the Alps and the Himalayas—zones that seemed to be huge thrust faults, folds of immense proportion, metamorphism at extreme conditions. Through the inspired power of analogy, Kai, John, their coworkers, and those who had come before them had surmised that the Greenland landscape was an old ancestor, a forerunner of the young mountain systems that today so dramatically exalt Earth’s skin. But the Greenland ancestors are long gone, erased by the incessant hunger of flowing water, blowing wind, and grinding ice to achieve a form of topographic equality between sea and land. Erosion always wins.
The first clear hint of those lost mountains had come years earlier. Just after World War II, the Geological Survey of Greenland (GGU) was founded in Denmark. Through its offices, a small group of geologists, including Arne Noe-Nygaard and Hans Ramberg, began the first systematic study of the west coast of Greenland, sailing along the complex coastline in motorized sailing vessels strengthened to resist collisions with ice. They found a two-hundred-mile-wide belt of rock that seemed to preserve evidence of multiple complex episodes of protracted and intense deformation. The belt was called the Nagssugtoqidian mobile belt, named for the region it cut through—Nagssugtoq—and the fact that the rocks seemed to have been twisted into structures that implied extreme plasticity and flow. The mobile belt ran east-west all the way across Greenland. Although the mobile belt seemed to represent a major orogenic, or “mountain-building,” event, how or why it formed remained enigmatic. Cutting through this region were several distinct zones, each zone a few miles to tens of miles wide, in which the rocks were steeply inclined and consistently aligned in the same direction. For some years, the significance of the zones of aligned rocks remained obscure, their tectonic significance unknown. But by the late 1960s and early 1970s it had been suggested by Arthur Escher and Juan Watterson, among others, that these zones contained rocks that had been severely sheared into steeply inclined parallel sheets and layers. The individual zones were eventually called shear zones and were named after the regions they ran through—Isortoq, Ikertoq, Itivdleq, and Nordre Strømfjord. The latter, the Nordre Strømfjord shear zone (NSSZ), became the center of attention because it marked the northern edge of the entire Nagssugtoqidian mobile belt. It was the only one for which observations were made near the ice—the others were only mapped while sailing along the coast, and their inland extent was unknown.
Geology is not generally considered an enterprise rich with drama. Rocks stolidly await inspection, slowly providing, through insightful consideration, a glacially paced story of incremental change. But there