Fundamental Soil Mechanics - Mathematics and Statistics for the Environment - page 306

few seconds relative to geologic time), the fracture's effects totally altered the shape of the peak
forever. During a horrendous windstorm, one of an intensity known only in Earth's earliest days,
a sharp tremor (emanating from deep within the Earth and shooting up the spine of the mountain
itself, up to the very peak) widened the gaping wound still more.
Decades of continued tremors and terrible windstorms passed (no present-day structure could
withstand such a blasting), and, finally, the highest peak of that time, of all time, fell. It broke off
completely at its base, and, following the laws of gravity (as effective and powerful a force then as
today, of course), it tumbled from its pinnacle position and fell more than 20,000 feet, straight down.
It collided with the expanding base of the mountain range, the earth-shattering impact destroying
several thousand acres. What remained intact finally came to rest on a precipitous ledge, 15,000 feet
in elevation. The pyramid-shaped peak, much smaller now, sat precariously perched on the precipi-
tous ledge for about 5 million years.
Nothing, absolutely nothing, is safe from time. The most inexorable natural law is that of entropy.
Time and entropy mean change and decay—harsh, sometimes brutal, but always inevitable. The
bruised, scarred, truncated, but still massive rock form, once a majestic peak, was now a victim of
Nature's way. Nature, with its chief ally, time, at its side works to degrade anything and everything
that has substance and form. For better or for worse, in doing so Nature is ruthless, sometimes bru-
tal, and always inevitable—but never without purpose.
While resting on the ledge, the giant rock, over the course of that 5 million years, was exposed to
constantly changing conditions. For several thousand years, Earth's climate was unusually warm—
almost tropical—everywhere. Throughout this warm era, the rock was not covered with ice and
snow, but instead baked in intense heat, steamed in hot rain, and endured gritty, violent windstorms
that arose and released their abrasive fury, sculpting the rock's surface each day for more than
10,000 years.
Then came a pause in the endless windstorms and upheavals of the young planet, a span of
time when the weather wasn't furnace-hot or arctic-cold, but moderate. The rock was still exposed
to sunlight but at lower temperatures, to rainfall at increased levels, and to fewer windstorms of
increased fury. The climate remained so for some years—then the cycle repeated itself—arctic
cold, moderately warm, furnace hot—and repeated itself and again.
During the last of these cycles, the rock, considerably affected by physical and chemical expo-
sure, was reduced in size even more. Considerably smaller now than when it landed on the ledge,
and a mere pebble compared to its former size, it fell again, 8000 feet to the base of the mountain
range, coming to rest on a bed of talus. Reduced in size still more, it remained on its sloping talus
bed for many more thousands of years.
Somewhere around 15,000 BC, the rock form, continuously exposed to chemical and mechani-
cal weathering, its physical structure weakened by its long-ago falls, fractured, split, and broke into
ever-decreasing-sized rocks, until the largest intact fragment left from the original rock was no big-
ger than a four-bedroom house. But change did not stop, and neither did time, rolling on until about
the time when the Egyptians were building their pyramids. By now, the rock had been reduced, by
this long, slow decaying process, to roughly ten feet square.
Over the next thousand years, the rock continued to decrease in size, wearing, crumbling, flaking
away, surrounded by fragments of its former self, until it was about the size of a beach ball. Covered
with moss and lichen, a web of fissures, tiny crevices and fractures were now woven through the
entire mass. Over the next thousand or so years, via bare rock succession , what had once been the
mother of all mountain peaks, the highest point on Earth, had been reduced to nothing more than
a handful of soil.
How did this happen? What is bare rock succession? If a layer of soil is completely stripped off
land by natural means (e.g., water, wind), by anthropogenic means (tillage plus erosion), or by cata-
clysmic occurrence (a massive landslide or earthquake), only after many years can a soil-denuded
area return to something approaching its original state, or can a bare rock be converted to soil.