The Two Floods: Catastrophism, Uniformitarianism, and the Heart of Geology

The historian W.E.H. Lecky once noted that "The direct antagonism between science and theology which appeared in Catholicism at the time of the discoveries of Copernicus and Galileo were not seriously felt in Protestantism till geologists began to impugn the Mosaic account of the creation." And, in all honesty, since most of the persecution of Galileo was for political and not theological reasons, we can date much of Catholicism's antagonism with science to this as well. We can even give it a very specific date: March 7th, 1785, the day James Hutton first spoke about his geological theories to the Royal Society.

James Hutton. [Image source]

Geology as a science existed before James Hutton, but he is nonetheless remembered as its father. Prior to Hutton, the dominant geological theory was Neptunism- the idea that all rock had precipitated out of the early oceans, primarily during Noah's flood. All fossils found in the mountains? They'd been laid there during the Flood. Neptunism is a form of catastrophism, which in this context means that the rocks of the world had been created by a great catastrophic event.

Neptunism had an early rival in plutonism, the belief that rocks were created in volcanic fire. Through the efforts of Neptunism's primary champion, German geologist Abram Gottlob Werner, however, Neptunism quickly rose to preeminence. One of the most telling facts about Werner? He had never left his home province of Saxony, nor did he particularly take to field work. He isn't the villain of this piece- he did make some important contributions to geology in his lifetime- but he would be overshadowed by our next actor to come along.

That actor, of course, was James Hutton. A British doctor turned gentleman farmer turned scientist, he was a member of the Scottish Enlightenment- a group of Edinburgh thinkers that also, among others, included Adam Smith and David Hume. Hutton's theories of geology based in his extensive fieldwork were nothing short of astonishingly perspicacious for his time. They weren't perfect- he thought marble was volcanic, rather than being metamorphosed limestone, among other errors- but he really did lay the foundation for modern geology. His most astonishing claim, however, was that the Earth was older than 6,000 years old. Much older. His book, The Theory of the Earth, ended with the astonishing sentence “The result, therefore, of our present enquiry is, that we find no vestige of a beginning, no prospect of an end.” Hutton was functionally denying the very biblical account of creation.

While that was the most controversial claim for the public, he started a much quieter but still fierce war inside geology. He also made the claim that "the present was the key to the past"- that the geology of the past was entirely produced by the processes active in the present. This was known as the doctrine of uniformitarianism. It took a couple generations for Hutton's theories to take over, but take over geology they did. Eventually, everyone fell in line behind uniformitarianism- too much so. Geology actually came to deny any claims of catastrophic events in the past.

Then, in the 1920s, the geologist J. Harlen Bretz proposed something astonishing: A massive flood had, during the Ice Age, torn through the Pacific Northwest all the way from Montana to the ocean. The flood had been produced by the collapse of a glacial lake comparable in size to one of the Great Lakes. There were countless bizarre channels, debris flow deposits, and other geological signs that had been puzzling geologists in the region, and many of them immediately made sense in the context of this theory.

A map of the extent of the Missoula floods. [Image source]

Nowadays we know that Bretz was correct- in fact, there were at least 25 separate floods as the lake, located near present day Missoula, Montana, reformed and collapsed again and again over the millenia of the Ice Age. These glacial floods, also known as jokulhaups, were immensely, insanely destructive. When the flood waters passed through the Columbia River Gorge and into the location of present day Portland, Oregon, the floodwaters were still over 400 feet tall and carrying along boulders the size of houses like they were leaves. 

At the time, however, Bretz was widely ridiculed. It took 40 years of further research for Bretz and his allies to convince the greater scientific community that he was correct. Even after that, claims that massive disasters produced geological phenomena remained controversial. It wasn't really until the discovery of the KT boundary and the Chicxulub crater- the proofs that the dinosaurs were killed by a giant meteor- that uniformitarianism's iron grasp on geology loosened. Today, uniformitarianism and catastrophism have both been consumed by a more nuanced and less rigid understanding of geology, which draws the best from both of them. It is much more uniformitarian in nature still- but it leaves plenty of wiggle room for surprises.

As for the antagonism between science and religion- well, that's both a topic that's been discussed to death on the internet, as well as the topic for another time.

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Bibliography:

https://en.wikipedia.org/wiki/Neptunism

https://en.wikipedia.org/wiki/James_Hutton

https://en.wikipedia.org/wiki/Missoula_Floods

https://en.wikipedia.org/wiki/Uniformitarianism

The Man who Found Time: James Hutton and the Discovery of Earth's History, by Jack Repcheck

Annals of the Former World, by John McPhee

Time's Arrow, Time's Cycle, by Stephen Jay Gould