Mountains of the Mind by Robert Macfarlane Page A

theory, as to that of Burnet so many years earlier, was immediate and voluble (‘Utter, damned rot!’, said the president of the American Philosophical Society, eloquently). But Wegener, a stoic visionary, remained phlegmatic in the face of early antagonism. In 1915 he published
The Origins of Continents and Oceans
, a careful explanation of his theory, and in its way as apocalyptic a reimagining of the earth’s history as Burnet’s
The Sacred Theory of the Earth
or Hutton’s
The Theory of the Earth
. Between 1915 and 1929 Wegener revised his
Origin
three times to take into account advances in geology, but he wasstill ignored by the geological establishment. In 1930 he led another meteorological expedition to Greenland. Three days after his fiftieth birthday he and his team were caught in a severe Arctic blizzard, in which temperatures dropped to −60°F. Wegener became separated from his companions, and froze to death in the private wilderness of a white-out. His body was found by his colleagues when the storm receded. They entombed Wegener inside a mausoleum built of blocks of ice, topped with a twenty-foot iron cross. Within a year, the structure and its contents had disappeared into the interior of the glacier on which it was built – a means of burial that would no doubt have met with Wegener’s approval.
    It was not until the advent of the so-called New Geology during the 1960s that it was realized that Wegener had been at least half-right. As advances in bathysphere technology permitted the more systematized exploration of the ocean floor, it was discovered that the continents did indeed move and had indeed spun apart from a vast ur-continent. But the continents weren’t – as Wegener had thought – independent entities drifting over a sea of basalt, like icebergs in water. In fact, the surface of the globe was discovered to be composed of some twenty crustal segments or plates. The continents were simply the portions of the plates which were sufficiently elevated to protrude from the sea.
    These plates were named by the New Geologists. There was the African Plate, the Cocos Plate, the North American Plate, the Nazca Plate, the Iran Plate, the Antarctic Plate, the Juan de Fuca Plate, the Australian Plate, the Arabian Plate and the decidedly unfragile China Plates. Driven by convection currents or ‘cells’ within the semi-liquid mantle of the earth, and pulled by their own weight, these plates move around relative to each other. Where their edges meet beneath the ocean, either a mid-ocean ridge or a subduction zone is formed. At mid-ocean ridges the boundaries of two plates are continuallybeing pushed apart by action in the mantle. Magma rises into the gap, and cools to form sea-floor basalt. Mid-ocean ridges are therefore raised above the surrounding ocean floor, like the seam on a cricket ball. A subduction zone, by contrast, is where the edges of two plates are forced together, and the less buoyant plate slides underneath the other. There, the rock of the subordinate plate is pushed down into the mantle, where it melts and comes bubbling back up in liquid form, causing super-heated wounds in the crust. These subduction zones form the oceanic trenches: the Aleutian Trench, the Java Trench, the Marianas Trench. At the bottom of these trenches – the Marianas Trench is deeper than Mount Everest is high – the atmospheric pressure is so enormous that, were you to materialize at that depth, your body would instantly be compacted to the size of a tin can.
    Most of the world’s mountain ranges have been thrown up by the jostling and collision of the continental plates. Thus, for example, the Alps were created when the Adriatic Plate (which carries Italy on its back) was driven into the Eurasian Plate. The oldest mountains are those which are now the lowest, for erosion has had time to reduce them. The blunted, rubbed-down spine of the Urals, for instance, speaks of great age. So too do the rounded forms of