Appalachian Seashells and the Age of the Earth


In the era of the American Revolution, intellectual topics like seashell fossils, the Genesis flood, and the age of the earth were all the rage. In December 1778, as the British prepared an invasion of Savannah, Georgia, seniors at Yale College held a debate on whether the flood had been global, or just restricted to the ancient Middle East. Writers associated with the “American Enlightenment,” not least Thomas Jefferson and Benjamin Franklin, speculated for decades over what the discovery of countless aquatic fossil shells in the Appalachian mountains meant about geological formation and the earth’s antiquity.

As Caroline Winterer’s imaginative new book American Enlightenments: Pursuing Happiness in the Age of Reason demonstrates, these discussions did not usually come with an overt secularizing goal. But exposure to the New World’s natural world, including those ancient Appalachian seashells, sent observers scrambling to fit new observations into traditional understandings of God’s timeline of creation.

The Christian tradition up to the era of the Enlightenment was hardly uniform in its beliefs about the age of the earth. Many European and American Christians in the mid-eighteenth century did, however, assume that the earth was about 6,000 to 10,000 years old, and that the six days of creation in Genesis represented literal 24-hour periods. The discovery of the aquatic fossils, for some, only confirmed what many had believed about Noah’s flood. Even the Appalachian Mountains were apparently covered by the floodwaters, which deposited marine life on the mountains.

Chimney Tops, Great Smoky Mountain National Park. Brian Stansberry, Wikimedia Commons. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
Chimney Tops, Great Smoky Mountain National Park. Brian Stansberry, Wikimedia Commons. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Others in the eighteenth century were more dubious about the effects of the Genesis flood. Even if it was a global flood, they contended, weren’t the mountains much older than the flood itself? Why then were many of the shells buried deep within the hills? Maybe the mountains were formed during God’s act of creation, and the seashells were displaced during that process, some argued. Maybe, one American explorer speculated, “this Earth was made out of the Ruins of another; at the Creation.”

Some began to argue that the geological layers might reveal epochs of time before humans inhabited the earth—maybe those shells fit into a timetable of Creation over an enormous length of time, well before humans and Noah’s generation. Prominent naturalists started to conclude that geological evidence suggested that the Earth itself was likely hundreds of thousands, if not millions of years old.

France’s Comte de Buffon suggested that the Earth might be just 75,000 years old, but even that relatively low number got him into trouble with Roman Catholic officials, who burned some of his books. Jefferson posited that some of the surprising fossil remains discovered in America could be as much as 250,000 years old.

Most of these theorists were not primarily seeking to undermine church authority or the traditional understanding of creation, but some like the notorious French skeptic Voltaire were trying to do precisely that. Voltaire scoffed at the “shells and systems built on shells” that sought to use the fossils to affirm flood-based geology. Shells were being discovered in geologic layers found deep under the earth (in mine shafts, for instance), which showed that they had been deposited there eons ago, in ages-old “revolutions of our planet.”

In the 1780s, Jefferson’s Notes on the State of Virginia (the only book he ever published) dispensed with the common theory that the shells appeared in the mountains as a result of a “universal deluge.” Jefferson also rejected the alternative theory that the shells came there as a result of an ancient “convulsion of nature,” perhaps at the time of creation. Intriguingly, Jefferson came to believe that the shells were a product of “spontaneous generation,” but by what means he did not know. Strikingly, Jefferson came to prefer a non-biblical theory about spontaneous generation (one that all observers now regard as false), rather than trying to fit new geological evidence into traditional biblical accounts.

By the way, in a typical secular scientific vein, the National Park Service tells us today:

The younger rocks of sedimentary origin [in the Smoky Mountains National Park] formed during the Paleozoic Era, 450 [million] to about 545 million years ago. These consist of compacted and cemented sand, silt, and clay deposited in an ancient shallow marine continental margin that existed in what is now the Appalachian region. Burrows and trails of worms, as well as small shells of crustaceans that lived in this shallow water along the ancient continental edge, are found in sandstone and shale in the northwestern part of the park. Fossils found in limestone rocks in Cades Cove are about 450 million years old.

Many figures of the scientific Enlightenment doubted the idea of an Earth that was 10,000 years old or less. But as Winterer explains, the “Genesis story was not so much explicitly rejected as quietly shelved in favor of more naturalistic explanations—or no explanation at all.” It was a story more of unintended consequences than a secularist plot.

Although much of the “Enlightenment” in Europe and America was led by people of devout faith, in matters of science and biblical authority the Enlightenment represented the beginning of a great parting of ways. From this point forward, many established authorities in science and religion did not operate in the same intellectual circles.

Among the most pressing challenges for believers today is to convey that there is no necessary contradiction between scientific study and biblical faith, and to discern which scientific “facts” the Bible presupposes and teaches, and which it does not. Everything the Bible reveals to us is infallibly true, but the Bible does not pretend to reveal comprehensive knowledge about all areas of life and science. On many issues, the Scriptures are silent.

Getting this balance right is of enormous practical significance in our churches and Christian families. Striking the right balance will help us to know, for instance, whether we must insist that our churches and children accept only one view of the earth’s age. I have Christian friends on all sides of that issue, so my inclination is to advise that we be charitable to those in the church (and outside the church) with whom we disagree on this most contentious topic.

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