Geological Names Are Not Carved in Stone

A good deal of arbitrariness and theory modification
over time goes into the naming of geological systems.

Did the Permian exist before 1841 when Roderick Murchison named it?

In a sense, yes; obviously the rocks existed long before he was born. But the concept “Permian System” cannot be understood apart from the theory used to describe and interpret it. When terms and concepts become entrenched in a culture’s thinking, it becomes difficult to look at rock strata without reference to the consensus taxonomy and theoretical framework in which they are embedded.

Conceivably, other cultures might attach entirely different names and concepts to geological layers within their purview. Could a modern geologist accuse such a counter-cultural view of being mistaken? “You’re wrong!” says a geologist. “That’s not Gribbleflix rock. That’s Permian!” What he would be doing is bullying the other into accepting his theoretical framework, not correcting something false about nature. Both cultures would have access to the same observations.

Semi-Arbitrariness

There’s more nuance here than pure arbitrariness, granted. The rock strata do indicate marks of abrupt change: unconformities, changes in color and mineral content, fossil content, and much more. A volcanic cinder cone cannot be lumped in with whatever name one gives to limestone or a glacial moraine. And specialists need a common language to understand one another. Currently, most scientists around the world accept the standard “geologic column” with all its appurtenances, such as dates of rock sequences and index fossils. The column has become extremely detailed down to named beds within each unit.

But neither can the arbitrary names and concepts of modern geology be judged as carving nature at its joints in a purely neutral way. One first has to decide what characteristics will matter in designating a new “system” such as the Permian, which was inserted between the previously-defined Carboniferous and Triassic systems. Murchison considered fossils, lithology and lateral extent as the definitive features worthy of a new system name, but what weights should given to each feature when they vary from place to place? Some strata may be extremely thick in one location, but pinch out to a thin lens elsewhere. Index fossils may be abundant one place, but absent in another place. Should limestone and sandstone both be called Permian? And why should one assume that the same geological history that took place in one part of the world, such as Britain, would hold true on the other side of the globe? Could there be a different Geologic Column on each continent, each with its own history and dating scheme? If not, why not? These are questions to ponder. Planetary scientists do that with other bodies, such as Enceledaus and Pluto, calling some regions “old” and others “young.”

As an exercise, consider other features that could be considered definitive if you were to start a new geological scheme from scratch. No matter the scheme, one will need auxiliary hypotheses when anomalies are encountered: strata out of order (or even inverted), out-of-place fossils, or (like in Grand Canyon; see illustration) locations where entire systems are missing, with strata above and below sitting conformably on one another. Where did the missing systems go? A story is needed.

To believe the consensus timeline, you have to accept multiple huge time gaps.

Consider too that many of the standard geological designations were made from observations of strata found in the British Isles, before geologists had explored other continents. Can strata in Utah or Mongolia be fit cleanly into nomenclature defined for Englishmen? If an African tribe ruled the world, would they have the right to impose their nomenclature on the Brits? These questions smear geology with issues of culture and politics as well. <satire>Is the Geologic Column racist, a heritage of imperialist white males?</satire>

Case Study #1

Two recent papers in the Journal of the Geological Society, a publication of the Geological Society of London, published in January 2022, allow us to probe these issues. (We resist the urge to parody the Geological Society of London as a white male club from the old imperialist days of the British Empire.)

The naming of the Permian System (Benton and Sennikov, Journal of the Geological Society (179:1), January 2022. The authors describe Roderick Murchison as “arrogant and imperialistic, which was undoubtedly true,” but say he was motivated to complete the last gap in the emerging concept of a global “geologic column” with his Permian designation. It was not accepted for a hundred years. Murchison based it on rocks from Britain and from Russia, probably assuming that rocks around the world would fit.

Roderick Impey Murchison (1792–1871) (Fig. 1) named the Permian System in 1841, plugging the last gap in the stratigraphic column. We now see this achievement as a great moment in the establishment of geology as a science. Murchison certainly hoped so and, as he was then at the height of his powers, he could use his elevated position as President of the Geological Society of London to drive home the point. In his annual addresses in 1841–43, he cast his eyes over the achievements of geologists around the world and emphasized that everyone should adopt the standard stratigraphic scale (including his Silurian, Devonian and Permian systems) worldwide. This fits with a common assumption that Murchison saw the naming of time as an urgent task and that he was able to promote his cause because of his domineering and autocratic approach.

What gave one white male in Britain the right to force his system on everyone else? There was no committee or congress to vote on such a far-reaching decision. The Russians liked it, and Murchison liked the Russians, but why didn’t the Americans or Indonesians come up with their own systems? That, of course, would cause major confusion, but agreeing on the names of rock units is only part of the problem. As stated earlier, the nomenclature is embedded in the theoretical framework in which they are interpreted, and that’s what Murchison and his followers were pushing for global acceptance. Murchison eventually succeeded largely by force of personality.

The concept of the Permian as propounded by Murchison was not widely accepted until the 1940s and he had to fight throughout his lifetime to keep the ‘Permian’ alive….

we consider whether Murchison really had an imperial plan to build an international stratigraphic timescale and impose it on the world, and how he and others viewed what he was doing. We explore the impact of Murchison and his work in Russia since 1840 and the remarkable fact that what Murchison called the ‘Permian’ represented only two-thirds of what we now call Permian, and indeed that leading geologists disputed his concept throughout his life and beyond and that the ‘Permian’ was only finally accepted internationally in 1941.

Back to our question: did the Permian exist before 1841 when Murchison gave it that name? The authors describe controversies like the “Great Devonian Controversy” and others that went on for decades. Murchison pushed his Permian but disliked another’s name “Trias” which became the Triassic. Instead of assuming that all the problems were eventually resolved by some neutral scientific method, or by the record of the rocks, one should ask whether the disputes were settled by a “domineering and autocratic approach” of a majority for the sake of gaining a consensus and ending debate. It’s so much easier to work when everybody agrees.

“The Naming of the Permian System” reads like a very human story of strong personalities clashing for dominance. Benton and Sennikov note that Murchison “spent the rest of his life, from 1841 to 1871, defending and promoting the idea of an international stratigraphic column encompassing as much of his nomenclature as possible.” He also “derived great pleasure in receiving and wearing medals and honours.” As CEH has repeatedly stated, science is not “out there” in a neutral realm. It is always mediated through fallible humans. Murchison was a good leader, but so was Napoleon.

In the next entry, we will look at current debates about revising the geological strata.