“To a naturalist nothing is indifferent; the humble moss that creeps upon the stone is equally interesting as the lofty pine which so beautifully adorns the valley or the mountain: but to a naturalist who is reading in the face of rocks the annals of a former world, the mossy covering which obstructs his view, and renders indistinguishable the different species of stone, is no less than a serious subject of regret.”
Basin and Range is the first book of John McPhee’s mighty five-book collection The Annals of the Former World. Each book, written between 1978 and 1998 and then later revised and updated, covers some facet of the geology of North America. Basin and Range is primarily concerned with the story of how the vast age of the earth has been measured (but scarcely comprehended), and the nature of plate tectonics–what it is, who figured it out, and how.
McPhee’s writing is a joy to read. From paragraph to paragraph, his subjects range from the minute to the cosmic in scale. He lingers on specific bits of knowledge and explains all that needs further elaborating with the exuberance of a passionate teacher. He somehow makes rocks interesting. Here he is describing the geological event that eventually made Nevada so hot and arid: “As the developing Sierra made its skyward climb–as it went on up past ten and twelve and fourteen thousand feet–it became so predominant that it cut off the incoming Pacific rain, cast a rain shadow (as the phenomenon is called) over lush, warm Floridian and verdant Nevada. Cut it off and kept it dry.”
In the conclusion, McPhee writes that “if by some fiat I had to restrict all this writing to one sentence, this is the one I would choose: The summit of Mt. Everest is marine limestone.” The earth is ANCIENT and in a state of eternal recomposition. That’s all you need to know, but it’s fun to read everything he has to say.
Video of a playa lake advance in Black Rock Desert, Nevada
Quotes and Anecdotes: The Naked Ambition of Langford Hastings and The Blind Man and the Elephant.
Buy on Amazon: Annals of the Former World
Stuff of Interest:
playa lake –Playa lakes are round hollows in the ground in the Southern High Plains of the United States. They are ephemeral, meaning that they are only present at certain times of the year. The temporal nature of playa lakes led to confusion on the part of early European explorers, some of whom described the region as a desert and others a land of millions of small lakes. Most playas fill with water only after spring rainstorms when freshwater collects in the round depressions of the otherwise flat landscape of West Texas, Oklahoma, New Mexico, Colorado, and Kansas. There are also a few saltwater-filled playas. These are fed by water from underlying aquifers, which brings salt with it as it percolates up through the soil. As the water evaporates, the salt is left behind in the increasingly salty playas. There are many theories as to the origin of playas, but the most widely accepted are that playas are either carved by wind or formed by land subsidence (they are sinkholes).
adsorb–(of a solid) hold (molecules of a gas or liquid or solute) as a thin film on the outside surface or on internal surfaces within the material.
Iapetus Ocean–an ocean that no longer exists! How crazy is that?
The Pikeville Cut-Through
Like all writing, writing about geology is masochistic, mind-fracturing self-enslaved labor—a description that intensifies when the medium is rock.
As the magma crystallized and turned solid, certain iron minerals within it lines themselves up like compasses, pointing toward the magnetic pole. As it happened, the direction in those years was northerly. The earth’s magnetic field has reversed itself a number of hundreds of times, switching from north to south, south to north, at intervals that have varied in length. Geologists have figured out just when the reversals occurred, and have thus developed a distinct arrhythmic yardstick through time. There are many other chronological frames, of course, and if from other indicators, such as fossils, one know the age of a rock unit within several million years, a look at the mineral compasses inside it can narrow the age toward precision.
At any location on earth, as the rock record goes down into time and out into earlier geographies it touches upon tens of thousands of stories, wherein the face of the earth often changed, changed utterly, and changed again, like the face of a crackling fire. The rock beside the road exposes one or two levels of the column of time and generally implies what went on immediately below and what occurred (or never occurred) above.
The whole region, very evidently, was the bottom of a lake, for a lake itself is by definition a sign of poor drainage, an aneurysm in a river, a highly temporary feature on the land. Some lakes dry up. Others disappear after the outlet stream, deepening its valley and eroding headward into the outlet, empties the water.
‘Zeolite’ means ‘the stone that boils.’ If you take one small zeolite crystal, of scarcely more than a pinhead’s diameter, and heat it until the water has come out, the crystal will have an internal surface area equivalent to a bedspread. Zeolites are often used to separate one kind of molecule from another. They can, for example, sort out molecules for detergents, choosing the ones that are biodegradable. They love water. In refrigerators, they are used to absorb water that accidentally gets into the Freon. They could be used in automobile gas tanks to absorb water. A zeolite called clinoptilolite is the strongest absorber of strontium and cesium from radioactive wastes. The clinoptilolite will adsorb a great deal of lethal material, which you can then store in a small space.
The human consciousness may have begun to leap and boil some sunny day in the Pleistocene, but the race by and large has retained the essence of its animal sense of time. People think in five generations—two ahead, two behind—with heavy concentration on the one in the middle. Possibly that is tragic, and possibly there is no choice. The human mind may not have evolved enough to be able to comprehend deep time. It may only be able to measure it.
In six thousand years, you could never grow wings on a reptile. With sixty million, however, you could have feathers, too.
Where plates separate, they produce oceans. Where they collide, they make mountains. As oceans grow, and the two sides move apart, new seafloor comes into the middle. New seafloor is continuously forming at the trailing edge of the plate. Old seafloor, at the leading edge of a plate, dives into deep ocean trenches—the Kuril Trench, the Aleutian Trench, the Marianas Trench, the Java Trench, the Japan Trench, the Philippine Trench, the Peru-Chile Trench.
The Himalaya is the crowning achievement of the Indo-Australian Plate. India, in the Oligocene, crashed head on into Tibet, hit so hard that it not only folded and buckled the plate boundaries but also plowed in under the newly created Tibetan Plateau and drove the Himalaya five and a half miles into the sky. The mountains are in some trouble. India has not stopped pushing them, and they are still going up. Their height and volume are already so great they are beginning to melt in their own self-generated radioactive heat. When the climbers in 1953 planted their flags on the highest mountain, they set them in snow over the skeletons of creatures that had lived in the warm clear ocean that India, moving north, blanked out. Possibly as much as twenty thousand feet below the seafloor, the skeletal remains had formed into rock. This one fact is a treatise in itself on the movements of the surface of the earth. If by some fiat I had to restrict all this writing to one sentence, this is the one I would choose: The summit of Mt. Everest is marine limestone.
All sciences involve speculation, and few sciences include as much speculation as geology.