Students of geology learn in their first semester that uniformitarianism is the guiding principle by which geologists interpret Earth’s history. The premise, as formulated by James Hutton in the late 18th century and argued persuasively by Charles Lyell in the middle 19th century, is that geological processes we observe today can be used to explain ancient geological materials and structures. For example, today we see the rock basalt forming by volcanic activity. Since we find basalt layers exposed in Shenandoah National Park, we presume that lavas oozed onto an ancient seafloor sometime in the distant past before the Blue Ridge Mountains formed.
Young-Earth Creationists and Flood Geologists reject the geological principle of uniformitarianism on the grounds that (1) it is inherently unbiblical, (2) it was developed to refute biblical catastrophism, and (3) it does not fulfill its promise to help us correctly interpret Earth’s history. These concerns are repeated in Young-Earth creationist literature and even from the pulpits of many churches. On his internet blog, distinguished American pastor John MacArthur (well known for his popular radio ministry) recently portrayed geological uniformitarianism as a dangerous dogma (here and here).
I respect Dr. MacArthur’s commitment to the authority of Scripture and his passion for the gospel message, but as a professional geologist and Christ-follower I found so many errors in his analysis that I feel they must be exposed in a similar forum. In a recent BioLogos post, Karl Giberson lamented the all-to-common situation in which “uninformed lay people presume to challenge the scientific community.” Pastors should not be expected to know all the nuances of a concept like geological uniformitarianism, nor the details of landforms and strata in some state park in Georgia (we will get to that). However, pastors should be cautious and responsible if they challenge the consensus of an established scientific discipline in the name of advancing the gospel.
Faulty assumptions, old definitions
Dr. MacArthur defined uniformitarianism as “the theory that natural and geological phenomena are for the most part the results of forces that have operated continuously, with uniformity, and without interruption, over billions and billions of years,” and that the “forces at work in nature are essentially fixed and constant.” There are elements of this description in nearly every textbook or dictionary definition of the term. I like the definition in the Glossary of Geology by Bates and Jackson: “The fundamental principle or doctrine that geologic processes and natural laws now operating to modify the earth’s crust have acted in the same regular manner and with essentially the same intensity throughout geologic time, and that past geologic events can be explained by phenomena and forces observable today....the doctrine does not imply that all change is at a uniform rate, and does not exclude minor local catastrophes.”
The example Dr. MacArthur gives to illustrate this principle is not how geologists apply it in their interpretations of Earth history. He writes, “The uniformitarian sees sedimentary rock strata...and assumes that the sediments that formed them resulted from the natural, slow settling of particles in water over several million years.” Geologists can point to very few natural environments of deposition where this kind of slow settling of particles actually occurs – the deep sea and large lakes come to mind. There certainly are some ancient rocks with textural properties that compare with deep sea and lake deposits. But, many more ancient strata compare perfectly with deposits of modern rivers, deltas, reefs and tidal flats (to name a few among many examples) that form by episodic accumulation of sediments in short periods of time (from seconds to centuries), separated by longer periods of non-deposition or erosion (from months to millennia and even longer).
Paradigm shift: uniformitarianism includes catastrophes
Dr. MacArthur mentions that fossils have a better chance of being preserved if they are buried suddenly (if not catastrophically). Uniformitarian geologists would agree! That’s because modern geologists don’t even subscribe to 19th century uniformitarianism. A paradigm shift occurred in the middle 20th century replacing uniformitarianism with actualism, an addendum to the principle allowing that extreme natural forces have acted in Earth’s history. For our purposes, we will use the term uniformitarianism as it is used by geologists today, not the 19th century definition. Uniformitarianism includes catastrophic events such as thousands of earthquakes from plate tectonics and various meteorite impacts (see footnote ii). As with all science, our understanding of processes has changed from the 19th century to the 21st century.
One of the turning points involved a unique landform called the channeled scablands in eastern Washington State that seemed to defy conventional explanations. Geologist J. Harlan Bretz proposed that they were formed by catastrophic floods of swift, deep water escaping from glacial lakes at the end of the last ice age.[i] The geological community eventually accepted his ideas, but it took over 30 years and some mind stretching to think about such forces as being normal or natural. Bretz was not motivated by biblical flood geology, but by following the evidence where it led him.[ii]
An old earth is not unbiblical
Dr. MacArthur claims that geologists have to keep increasing the age of the earth to make time for all the catastrophes evident in the rock record. That comment ignores the historical development of the geologic time scale as eventually quantified by the middle of the twentieth century. Geologists have known that the earth is in the range of 4.5 billion years old since the 1950s.
Our understanding of Earth history was advanced by thousands of geologists since Hutton and Lyell laboring over the details the earth’s crust and considering each stratum in the context of the planet as a whole. They abandoned the ideas of a very recent creation and global deluge of geological significance because those ideas were not supported by the geological data.
Many of the early geologists knew the implications of the emerging picture for the biblical accounts of origins and they looked to Bible scholars of their time for help. Modern evangelicals know those Bible scholars who accepted the new geology and showed that it was not inconsistent with the meaning of Scripture. Men like B. B. Warfield, James Orr and George Fredrick Wright; men who also contributed to the origins of the fundamentalist movement. Just as respected evangelical biblical scholars of our generation find an ancient creation no threat to biblical faith, such as Alister McGrath, C. John Collins, Bruce Waltke, Wayne Grudem, John Walton and Walter Kaiser.
Dr. MacArthur’s blogs conclude with the geological example of Providence Canyons in southwest Georgia to show the ineptness of uniformitarianism. Poor farming practices in the last century in this upland plateau resulted in severe erosion of the natural drainage system, cutting numerous gullies up to 130 feet deep. If Georgia’s Little Grand Canyon could form in only decades, why couldn’t receding water from Noah’s flood carve Arizona’s Big Grand Canyon? That both canyons were carved by water is about the extent of the comparison! A detailed look at the strata eroded in Providence Canyons provides further evidence that actualistic assumptions work.[iii]
Uniformitarianism reflects God’s unchanging nature
Finally, do we really want to condemn uniformitarianism, or its offspring actualism, as an unbiblical premise? Dr. MacArthur quotes scriptures that ring of the catastrophist actions of God in nature. However, there are also scriptures that speak of the unchanging nature of God and...well, nature. Ecclesiastes 1 comes to mind with its poetic refrains: “Generations come and generations go, but the earth remains forever....All streams flow into the sea, yet the sea is never full. To the place the streams come from, there they return again.....What has been will be again, what has been done will be done again; there is nothing new under the sun. Is there anything of which one can say, "Look! This is something new"? It was here already, long ago; it was here before our time. There is no remembrance of men of old, and even those who are yet to come will not be remembered by those who follow.”
In Part 2 and Part 3, Gregory Bennett will explore how the concept of uniformitarianism as used by geologists is necessary for our full understanding of God’s relationship to nature. He will also explore how uniformitarian principles are used by every biblical interpreter including use within one of the core tenants of Christian doctrine, God’s providence.