The Rocks Don't Lie: A Geologist Investigates Noah's Flood (9 page)

World in Ruins

L
ONG BEFORE GEOLOGY DEVELOPED
into a distinct discipline in the nineteenth century, novel theories abounded about how Noah’s Flood shaped the world. In Galileo’s day, three camps defined seventeenth-century views of topography. First, those who did not think too deeply about such things generally believed landscapes were just two days younger than Earth itself, sculpted by the hand of God on the third day of creation. Then, there was the more scholarly view that valleys and mountains were carved by the Flood. Finally, some natural philosophers allowed the earthquakes known to have happened occasionally through history a minor role in shaping the land. Conventional wisdom still held that the world had been gradually wearing down through its short history. The future promised further decay as topography eroded and soils lost fertility.

The view of the world as a wrecked and ruined place began to change in 1644 when renowned philosopher René Descartes set forth how Noah’s Flood followed his principles of nature—the laws of physics as he laid them out in his
Principia Philosophiae
. One of his theories concerned Earth’s origin and evolution. Mindful of Galileo’s treatment by the church, and well aware that his ideas did not accord with sanctioned interpretations, Descartes explicitly stated that his own theory was wrong. Cleverly inoculated from official censure, he claimed to offer a hypothesis useful for better contemplating nature.

Descartes painted a picture of an Earth that began as a failed star trapped in the vortex of a neighboring star. The primitive Earth then cooled and segregated into a planet with distinct layers, leaving a still fiery core surrounded by a metal-rich inner crust. Above this lay an ocean, trapped below an outer crust made of stones, sand, and clay. Over time the heat of the Sun evaporated water trapped between the inner and outer crusts. Fissures coalesced into large fractures as the undermined and weakened outer crust foundered into the watery abyss, triggering a great flood and forming both mountains and seas.

Descartes’ imaginative idea offered a way to generate the world’s topography all at once. His grand physical explanation for how to generate a global flood inspired other natural philosophers to think up ways to trigger the biblical flood. With little evidence available to contradict or refute any idea no matter how outrageous, competing flood theories soon posed creative ways to explain how God designed a world preprogrammed for destruction.

Today, such theories seem fantastically ridiculous, like bizarre figments of feverish minds. But in their day, they were serious attempts to explain the world. Imagination raced ahead of understanding as the reality of Noah’s Flood was taken on faith in theories devised to explain the origin of topography. Facts only started to get in the way of a good theory once geological principles were systematized.

After Galileo’s ordeal, Jesuit scholar Athanasius Kircher became a leading voice among clergy interested in natural history. Professor of mathematics, physics, and Oriental languages at the Jesuit College of Rome, he published lavishly illustrated natural history books that became wildly popular among the European elite. An eccentric by any standard, Kircher explored deep grottoes and canyons, even having himself lowered into the volcanic craters of Etna and Vesuvius to see what lay below ground. Finding subterranean streams high in the Alps, he saw the fact that some caves were filled with water and others with fire as the key to one of Earth’s great mysteries—the origin of rivers. His
Mundus Subterraneus
(
Subterranean World
), an encyclopedic compilation of geologic fact and fable published in 1664, suggested that ocean tides pumped seawater up into mountains through underground channels that connected to springs at the head of rivers. Fires deep beneath volcanoes, acting like a global radiator system, drove water up from holes in the bottom of the sea to feed mountain springs. Kircher had the concept of a hydrological cycle right, but the direction backwards. Today we know that water evaporates from the oceans and rains down on the continents and then runs off into the sea.

A decade later, in his
Arca Noë
(
Noah’s Ark
), Kircher maintained that God unleashed Noah’s Flood by causing vast underground lakes to overflow. Great blocks of the planet’s outer shell foundered into his subterranean reservoirs, leaving distorted layers of broken rock standing above ocean basins and lowlands. Mountains were the collapsed ruins of Earth’s original crust.

Not everyone was convinced the flood was global. Kircher’s contemporary Isaac Vossius, Dutch theologian and librarian to the Queen of Sweden, argued for a local flood on the grounds that there simply was not enough water on Earth to submerge the highest mountains. He dismissed as pious fooleries proposals that God miraculously created extra water and then just as miraculously made it all disappear. Vossius argued that the few generations between Adam and the Flood could hardly have populated Mesopotamia, let alone the entire planet. Instead, he proposed that people must have occupied a limited area in Noah’s time because it was senseless for God to punish uninhabited places. Besides, the ancients often used universal terms to describe local events. The Flood need only have been universal in the sense that it overwhelmed humanity’s ancestral homeland. In his reading, the Bible revealed Noah’s Flood to have been a local affair.

The amount of water required to flood the world also was a sticking point for Edward Stillingfleet, the Anglican Bishop of Worcester, who in 1666 wrote
Origines Sacrae
(
Sacred Origins
). He too considered a local flood consistent with biblical orthodoxy. According to his calculations, the world’s clouds could only produce enough water to cover the globe with a foot and a half of water—nowhere near enough to submerge the whole planet. Stillingfleet echoed Vossius in thinking that a regional flood could have destroyed mankind if humanity was restricted to the Middle East. A flood that affected a small part of the world would also mean that Noah only needed to load representatives of part of the animal kingdom on his ark. Stillingfleet did not favor invoking additional miracles not mentioned in scripture to explain a worldwide flood, or the logistical challenge of feeding a boatload of animals when all the world’s edible plants lay submerged beneath the waves.

Stillingfleet and Vossius helped establish the legitimacy of belief in a local flood among theologians, but the propensity to interpret Noah’s Flood as a global deluge did not fade easily. Prominent seventeenth-century natural philosophers continued to use Noah’s Flood to explain geological observations, among them the grandfather of geology.

The Dane Niels Stensen, better known as Steno, was the son of a successful Copenhagen goldsmith. Born into a Lutheran family on New Year’s Day in 1638, Steno was taught that at most the world would last another couple of centuries before God ended everything. His deep religious faith and strong interest in natural philosophy greatly influenced how he came to lay the foundation for modern geology. Raised in a Protestant stronghold of biblical literalism, he later worked and lived in Catholic countries where allegorical interpretations of the Bible were deeply rooted. His gradual migration south would change his worldview and encourage his curious, wondering mind to think broadly.

At the age of eighteen, Steno enrolled at the University of Copenhagen to study medicine. There he learned the supposed curative properties and medicinal virtues of crystals and fossils such as tongue stones—rock-hard triangular objects with serrated edges. Prized since ancient times, powdered tongue stones were thought to ward off evil or attract affection and were commonly sold as cures for plague and bad breath. They could be found scattered on bare ground after heavy rainstorms, and there were many theories of how they formed. Some thought the strange objects fell from the sky. Others thought that they were petrified lightning strikes. While tongue stones and fossils interested Steno, he loved anatomy lessons involving the dissection of human bodies.

In 1659 Steno slipped out of Copenhagen, eluding the Swedish troops besieging the city. After a brief stay in Amsterdam, he finished his medical training at the University of Leiden. There his skill as an anatomist led him to the scientific discovery that made him famous. Recreationally dissecting a sheep’s head, he discovered the saliva duct. Until then how saliva got to the mouth was a mystery. He went on to discover tear glands, disproving the conventional wisdom that pain or grief squeezed tears from the brain.

Following his graduation in the winter of 1665, Steno came to Paris. There, he boldly challenged Descartes’ claim that the tiny pineal gland housed the human soul near the seat of the brain. Steno’s careful dissection of human brains disproved the great philosopher’s assertion that the nut-shaped gland twisted and pulled strings animating the human body. Steno showed that the pineal gland was held fast and could not gyrate. He continued to startle the scientific establishment in Paris when he then contributed significantly to understanding the workings of the human heart.

Now a scientific sensation, Steno was offered the position of physician to Ferdinand II, Grand Duke of Tuscany. With this came access to the Accademia del Cimento (Academy of Experiment), the first and only formal research lab of its day—founded by students of Galileo and supported by the grand duke’s deep pockets. Steno’s journey to Florence carried him across the Alps and Apennines, where he saw fossils layered in rocks high above sea level, well beyond the reach of even the largest waves. Some rock layers lay flat, others were contorted and lay at steep angles. While the fossils in the hills around Florence looked like seashells, most natural philosophers did not consider them signs of ancient life. The educated consensus was that they were insignificant mineral oddities, sports of nature that merely resembled oysters and clams.

Soon after Steno arrived, in October 1666, fishermen on the Tuscan coast hauled in the body of a monstrous great white shark near the mouth of the Arno River. When word of the several-ton beast reached the Medici palace, Ferdinand ordered it brought to his court in Florence for the Accademia to examine. But the shark was too large to transport and was already starting to rot. So its enormous head, as big as a whole pig, was loaded onto a horse-drawn cart and sent up the Arno River valley.

Steno, the academy’s newest member, considered the honor of dissecting the enormous shark’s head a once-in-a-lifetime opportunity. He cut as the grand duke and a mesmerized crowd of courtiers watched. The jaws were large enough to swallow a man whole. Yet its brain was tiny—just three ounces. How could such a diminutive brain control a giant killing machine?

Steno focused first on its teeth. Each serrated blade was identical to the mysterious tongue stones. They were as identical “as one egg resembles another.”
¹
Seeing that tongue stones were actually shark’s teeth, he wondered how the teeth of giant sharks could end up enclosed in solid rock. They must have become fossilized after laying in the mud of an ancient seabed that somehow became stranded high above the sea.

Steno described his findings in a short report to the grand duke, with a digression on the origin of tongue stones and the implications for understanding other fossils. He pointed out the flaw in the conventional wisdom of the time: that fossils spontaneously grew within rocks. A growing object would crack the rock, yet one never saw cracks around fossils found in rocks. Even more telling was that tongue stones were always perfect replicas of their biological counterparts. In contrast, most crystals contained a defect, even when grown in a lab. Steno argued that fossils resembling broken mussel shells found with their matching halves preserved in rock inches away from each other could only be explained as the remains of once living creatures.

Steno’s demonstration that tongue stones were petrified shark teeth convinced scholars that fossils were indeed organic remains. His interest in the problem of solids enclosed within solids—how fossils got into rocks—led Steno to deduce that the bottom layers in a pile of sediment were deposited first. This is the foundational principle of modern geology, Steno’s Law of Superposition—the idea that the oldest sedimentary layers are on the bottom and the youngest are on top. It’s still valid centuries later; I used this same basic rule to interpret the geologic story when I hiked out of the Grand Canyon.

Steno thought that some rocks were made of consolidated sediment washed off the land and that other rocks precipitated from mineral laden waters. Fossils were the remains of sea creatures buried by gradual deposition of sediment on the seabed. This was why fossils tended to be the most durable parts of marine creatures (teeth, bones, and shells). Soft tissue decayed too rapidly to be preserved.

Steno’s prescience is astounding given the time in which he lived and the countervailing convictions of his peers. The impact of his shark head dissection and the short yet wildly influential publication it spawned in the spring of 1667 show the serendipitous nature of scientific progress. Steno subsequently began working on a longer masterpiece that laid geology’s foundation. In trying to explain how shark’s teeth ended up in rocks, he devised rules for how to read geologic history from the rocks themselves. Whereas Descartes and Kircher developed their ideas from sweeping generalities based on classical ideas backed up by little, if any, geologic evidence, Steno studied Earth’s history by applying guiding principles and logic. He didn’t just make up a good story to explain how he thought things worked; he went out and scoured the countryside for clues to build up ideas that were grounded in field evidence.

As he grew increasingly enamored with geological problems, Steno began collecting fossils on long hikes in the Tuscan mountains. Indulging Steno’s curiosity, the grand duke opened quarries and mines to expose what lay underground. The more Steno observed, the more he became convinced that an ancient sea deposited fossil-bearing rocks. He also noted how some rock layers lay at an angle to the horizon, meaning that they had been tipped up on end after they were deposited.