By Robert Hazen, Ph.D., George Mason University
James Hutton was a Scottish geologist who believed that great geological change could have taken place through countless decades of gradual increments called “uniformitarianism”. This idea is in sharp contrast to “catastrophism”, a competing doctrine, which argued that most of the Earth’s features arose through violent events, particularly one dramatic flood.
James Hutton, the founder and the great champion of uniformitarianism, lived from 1726 to 1797.
By his early forties, he had retired to study geology, particularly in the area around Edinburgh. He particularly enjoyed the rich intellectual life around that city in the 1780s and 1790s.
At this time, the prevailing wisdom was that the Earth was about 6,000 years old; that’s all. This is in accordance with the literal interpretation of the Biblical chronology; particularly the chronology proposed by Bishop James Usher, who lived from 1581 to 1656.
Under such a climate of religious thought, very few people thought about the implications of millions, or hundreds of millions, or even billions of years of change; but Hutton was different.
This is a transcript from the video series The Joy of Science. Watch it now, on Wondrium.
Noachian Deluge and Geological Doctrines
At the time, most geological features were interpreted as the result of the one great catastrophic flood, which was the Noachian deluge, and this belief supported two prevailing geological doctrines of the 18th century.
The first was catastrophism, that geological change occurs through catastrophes. The second was called “neptunism,” and that’s the idea that rocks are formed primarily through the action of water, either as sedimentary layers of particles deposited one on top of each other or often through chemical precipitation. Many people thought that basalts and limestones were just chemical deposits precipitating out of water.
However, Hutton differed. He realized that the most dramatic changes in the Earth’s surface are told by the testimony of the rocks, in outcroppings, in cliffs. He traveled from outcrop to outcrop around his native Scotland, and he learned the dramatic story that the rocks had to tell.
Learn more about the rock cycle.
A Great Discovery by Hutton
One of the greatest discoveries was Hutton’s interpretation of a remarkable cliff near the town of Jedburgh in Scotland; that’s about 35 miles east of Edinburgh. At this rock outcropping, there are intensely folded layers of rock at the bottom of the hill; very, very intensely folded, but they’re cut off. On top of those rocks are layered flat-lying sediments, containing evidence of sedimentation and also containing fossils.
In these rocks, what Hutton saw was a succession of periods of sedimentation: burial, compression, folding, and then uplift and erosion, each one of which had to take millions of years.
First, he said there must have been some shallow ocean or sea, and sediments were deposited layer by layer in a flat-lying way. Then those layers had to be buried. They had to be heated, compressed and turned into rock layers. Then some great forces, tectonic forces, came along and squeezed them so that those flat layers became intensely folded; and that had to have occurred deep underground.
Following that, there had to be a period when all those rocks were uplifted to above sea level because one could see the erosional feature. Then they had to be buried again, under another sea or ocean. Then there had to be more layers of sediments deposited; they had to be buried deep enough so that those layers were turned into rock.
Finally, the whole thing had to be uplifted once again, cut by some river or stream, and one could see the cliff face.
Volcanism: Essential Agent of Change
In all these processes, Hutton also saw the Earth’s inner heat as an essential agent of change; and this point of view is called “volcanism”, in sharp contrast to neptunism. Here’s Hutton saying that rather than catastrophic events and water being the principal agents of change, you also have to look for immense periods of time, and heat being an agent of change.
Over, and over, and over again, he said, these processes have occurred, and the cycles take tens or hundreds of millions of years, maybe even longer. He saw no way of telling how long the vast spans of geological time were; but certainly, to be limited to 6,000 years was an absurdity, in his view.
“The Theory of the Earth”
Hutton’s ideas were published in a revolutionary but largely unreadable text, called The Theory of the Earth. In Hutton’s own words, he said, “The result, therefore, of our present inquiry is that we find no vestige of a beginning, no prospect of an end.” Unfortunately, the way Hutton wrote was so indecipherable in the text of his work that most people just ignored it.
But Hutton’s great friend, John Playfair—also a resident of Edinburgh— aided the acceptance of uniformitarianism by his very persuasive popular account, Illustrations of the Huttonian Theory of the Earth, which was published in 1802.
Learn more about the Earth as a planet.
Consequences of Cumulative Change
There are many examples of the dramatic consequences of slow, cumulative change, and you can see them all over the world.
In many places, including the absolute highest mountains in the Rockies, the Alps, the Himalayas, you find fossils of sea creatures at the highest point. At the highest-most rocks of Mount Everest are limestones that were deposited once in an ocean; and have somehow, over geological time, been uplifted to the highest land point on Earth.
The Earth is a dynamic planet that’s constantly undergoing change. All of these geological processes, acting over millions of years, lead to dramatic change, and alteration of the Earth’s surfaces.
Common Questions about James Hutton and Uniformitarianism
James Hutton was a geologist who lived in Scotland between 1726 and 1797. He was the founder and the great champion of uniformitarianism. He believed that geological changes had occurred gradually over billions of years.
One of James Hutton‘s greatest discoveries was the remarkable rock interpretation near Jedburgh, Scotland. What Hutton observed on these rocks were successive periods of sedimentation; each having taken millions of years to form.
Hutton’s ideas were published in a revolutionary but largely unreadable text, called The Theory of the Earth. The way Hutton wrote was so indecipherable that most people just ignored it. But Hutton’s great friend, John Playfair, aided the acceptance of uniformitarianism by his very persuasive popular account, Illustrations of the Huttonian Theory of the Earth, which was published in 1802.