Preface

      DESTINATIONS, WHETHER NEW OR OLD, are expectations shrouded in imagined landscapes. We set off with ideas for adventures that we hope might materialize and we imagine pathways to things we fear but secretly wish to confront. We think of our destination as an end point to a journey, but its reality is seldom that. Destinations may also evolve into portals that devour expectations, immersing us in the inconceivable. So it is for me when I travel into the Greenland wilderness.

      FOR A GEOLOGIST, GREENLAND IS A DREAM. The ice, receding faster than plants can take hold, exposes in its retreat the polished bedrock floor it has ridden on for millennia. Glistening in the sun, emphatic in its insistence for attention, an unexpected artistry offers itself for inspection.

      That rock can flow always astonishes, but revealed in those outcrops are patterns that imagination could never conjure, proving beyond doubt that the continental heart is barely less fluid than water. Layer upon layer, some a fraction of an inch thick, some thicker than houses, colored in a palette of earth tones and off-whites, greens and blue-blacks and reds, fold back on one another, pinch and swell, stretch to paper thinness, then thicken again, telling stories we ache to know but can barely read.

      I go to Greenland with two Danish geologists, Kai Sørensen and John Korstgård, to unravel these mysteries. For weeks at a time, camping in one of the world’s greatest untouched wilderness expanses, we wander through a twenty-thousand-square-mile landscape, crawling over outcrops on hands and knees, struggling to piece together fragmented clues to what the story line may be. It is the ultimate in forensic science, cobbling from a hundred different techniques, technologies, and fragmented logical arguments a consistent tale that encompasses nearly the entire history of nonhuman Earth.

      Our research, and that of colleagues stretching back to the 1940s, has provided only the barest outline of that history. We have established little beyond that it is a mystery involving life and rock and the symbiosis they have woven. If a book were the analogy, the covers would be mainly complete but the ink of the chapters nearly faded.

      That so little has been accomplished should not be surprising. The region is above the Arctic Circle, so daylight and sufficiently warm temperatures to allow camping are available only a few months during the year. The remoteness of the area, requiring special arrangements for transportation into and out of the wilderness, challenges logistical efforts. It is a vast terrain of unexplored landscape; only a few details are well established.

      What has been exposed thus far is a tantalizing mystery. Preserved in the bedrock are vague suggestions that multiple mountain-building episodes occurred there sometime between two and three-and-a-half billion years ago. The most recent of those events may have been so massive, it would have foreshadowed the Himalayas. There is evidence of movement along enormous faults; of volcanic systems that would rival the Andes; of ocean basins the size of the Atlantic. All are now vanished, swallowed in the onward rush of Earth’s evolution. The observations supporting these notions are few, the data difficult to interpret.

      Compounding the challenge of this research has been uncertainty about the fundamental assumptions upon which the science is based. All geological studies dealing with present-day processes on Earth are grounded in plate tectonics. Plate tectonics defines the Earth as a dynamic planet in which heat from the deep interior powers the slow migration across the surface of twelve plates of ocean and continental crust. Mountains form where plates collide, and crust forms where plates separate—the consistency of the process of crust creation and destruction fulfills the requirements of a self-contained system, a zero-sum game. Recognized and accepted evidence for the persistent operation of this process extends 900 million years into the past. Beyond that time, the evidence is equivocal and energetically debated. Since the rocks in Greenland are much older than that, we are left uncertain as to how to interpret what we see and what the motivating forces would have been.

      The rocks we work on are from a transition period. Life, though soft-bellied and delicate, has been the most powerful chemical agent on Earth. The atmosphere of our planet is a product of its breathing, the composition of oceans and rivers a consequence of its metabolism. Even the continents are its product—over 3,800 million years ago, the remnant structures of photosynthesis, mixed into the mantle, encouraged melting that oozed from that deep interior, coalescing to become the landmasses we walk on.^* Was that when plate tectonics began, or was plate tectonics some later phenomenon predated by an energetic process we do not know? The rocks we collect and study preserve the answer to that question.

      WE CONDUCT OUR STUDIES IN that little-known fringe of land that extends over a hundred miles west from the edge of the Greenland ice sheet. Although our scientific interests are purely academic, the experiences we have lived through are almost mystical. We camp for weeks at a time in one of the world’s largest unbroken wilderness realms. Utterly alone, voluntarily isolated from the rest of humanity, we walk and sail without resistance through a world that, for the most part, has never