Reflections on Geologic Time, The Problem with Granite vol. I

Da Vinci and Steno's observations and conclusions about the nature of fossils concerned layered rocks, rocks formed from particles ("sediment") that are moved about by common processes active at the Earth's surface: gravity, wind, water, and ice. There was, of course, another problem. How did granite form?

Whiston and Burnet were proponents of explanations consistent with Biblical accounts. Aristotle had advocated that knowledge was rational and independent of the senses; it was to acquired by reasoning, intuition, and revelation of the innate properties of things. This approach was very successful at preserving the knowledge of books that had survived the Middle Ages and presented a consistent picture. Fossils were in the rocks because they had always been there; fossils on mountaintops were consistent with the Biblical account of a global flood. However, Da Vinci and Steno were neither satisfied nor complacent with the status quo and these renegades relied, instead, on what they could observe.

This division between what is known or knowable and what can be observed had a profound effect on infant science. The rationalist approach of Aristotle was on its way to the wings while Rene Descartes (1596-1650) and empiricism took center stage. Descartes advocated a method of doubt and argued propositions should not be accepted until logically proven. What you could see and touch took precedence over intellectual reasoning alone.

Abraham Gottlob Werner (1750-1817) was the leading Neptunist of the time. He advocated the idea that granite had crystallized from minerals in Earth's early oceans. He based much of his reasoning on Whitson's 1696 book, New Theory of the Earth and assumed the inerrantcy of the Biblical accounts of creation and the flood. Werner applied Steno's Law of Superposition and proposed five divisions of rock units that is often recognized as the first attempt at a scale of relative geologic time.

• Volcanic or Quaternary was applied to lava fields and other young rocks on top of the Tertiary. Werner felt the heat required to melt rock was from coal burning underground.
• Tertiary or Alluvial referred to unconsolidated sand and gravels
• Secondary or Stratified were solid layered rocks with fossils that originated as mountains that emerged from global oceans (the seashells were now on the mountaintops)
  
• Transition referred to world wide rocks deposited by flood. Werner proposed these rocks generally contain no fossils.
• Primitive rocks were the crystalline rocks representing the first precipitates from the ocean before land emerged

Werner and the Neptunists were opposed by the Plutonists. Anton Moro (1687-1750) published concerning the seashell on the mountain top problem (no, I don't speak or read Italian) and studied volcanic islands. Based on his studies of volcanic islands, he proposed that granites had originated as molten liquids. The chief proponent of Plutonism and Moro's thoughts on the origin of granite was James Hutton (1726-1797) who became known as the Father of Geology. Hutton's Theory of the Earth (and here) was first read before the Royal Society of Edinburgh in 1785, but was considered by many to be essentially unreadable. Hutton felt the core of the Earth was the source of the heat for melting rocks (like lava). He demonstrated that granites were formed, not by precipitation from an ocean, but by crystallization during cooling of melted rock. He did this by tracing granites laterally to where they contacted sedimentary rocks and had baked the sediments like bricks. Hutton argued for uniformitarianism, the idea that the processes that are forming rocks today formed rocks in the past and at essentially the same rates. Hutton also expanded Steno's three principles with the principle of cross-cutting relationships: a rock unit (dike), fault, or fracture that cuts across other rocks must necessarily be younger than the rocks that hosts the feature.

Hutton is also credited with the discovery of “deep time.” While observing the outcropping of rock at Siccar Point, Scotland, he experienced an epiphany that led to the concept of an “unconformity.” The outcrop exhibits a series of layered rocks that are near-vertical and overlain by horizontal rock layers. Hutton realized that the outcrop couldn’t have been formed in a flood. Rather, the upstanding layers had to have been deposited nearly horizontally (Steno), were bent into their upright position, a younger set of horizontal rocks were deposited on top, and finally everything was uplifted from the sea to its present position where Hutton could see it. The surface between the older upstanding rocks and the younger flat rocks must represent a missing period of time not represented by rocks in that outcropping. Geologists now recognize unconformities as a time of erosion or non-deposition.

Hutton, of course, didn't win the origin of granite debate immediately. It wasn't until John Playfair (1748-1819) and Charles Lyell (1797-1875) expounded upon and popularized his ideas that the origin was solved (at least for the time, more later).

For more on rationalism versus empiricism, see the Stanford Encyclopedia of Philosophy. For more on deep time, see Steven Jay Gould's book, Time's Arrow, Time's Cycle.

Reflections on Geologic Time, How the Debate Started

In Kentucky, issues and discussions related to separation of Church and State seem De rigueur. In public school classrooms, statutes require the Bible to be read (KRS 158.170), the Lord's Prayer may be recited as a reminder of the Freedom of Religion (KRS 158.175), and there is a right to include creationism when evolution is taught (KRS 158.177). More recently, Gov. Beshear announced the grant of tax incentives to developers of an Ark Encounter park next to the Creation Museum, both associated with the the ministries of Ken Ham's Answers in Genesis. There is a bill making its way through the current regular session of the General Assembly that would require the development of an elective social studies Bible literacy class in public schools. (The bill has passed the Senate and is assigned to the House Education Committee as of 2/14). The potential constitutional issues of the statutory provisions are addressed by allowing students to elect to be silent or excluded, but to the best of my knowledge, there has been no First Amendment challenge in the courts. Beyond pointing out that my position is strongly in favor of separation of Church and State, my purpose is not to argue the constitutionality (or rationality) of these issues here. My inte3nt is to take a historic look at geologic time.

As western civilization emerged from the Dark Ages, questions of the origin of the Earth and life were hotly debated among the cognoscenti. No answers beyond Biblical were required. God created the Heavens and Earth in 6 days, Adam and Eve were expelled from Eden, and there was a global flood. Bishop James Ussher made a scholarly examination of the Bible and manuscripts available at the time and published his Biblical chronology in 1650. This chronology, published in the gutter between the columns of the printed Bibles, has become the cornerstone of the argument that the Earth is less than 10,000 years old. The answer to two pressing questions would lead to the emergence of geology as a science and the dismantling of the Biblical account:

• What are fossils?
• How did they get to the tops of mountains?

In his notebook now known as the Codex Leicester, Leonardo da Vinci (1452-1519) contemplated the answer to those questions. It was pretty obvious that the shells in the rocks resembled shelled creatures living in the sea and some people advanced the proposition the creatures had lived in the rocks. Da Vinci observed that the shells were of multiple sizes and exhibited growth lines. He argued they could not grow without food nor could they move in rock to get food. He also observed that if there were a worldwide flood, there would be nowhere for the water to go when it receded, that the shells would have been carried and mixed up in a single muddy deluge and not deposited in regular steps and layers, and that rains and floods would carry fossils downhill and away from mountaintops and land. Leonardo described oysters and corals and considered it impossible that a single flood could have carried them 300 miles inland. Leonardo concluded that the fossils were once living organisms that had been buried at a time before the mountains were raised.

As an aside, Bill Gates purchased the Codex Leicester and through one of his companies, Corbis, a multi-media CD-ROM for exploring the Codex was published. Unfortunately, that CD has been out of print for several years, but it might be found at local public libraries. I don't know whether it still runs on current computers.

A conclusive demonstration that fossils were once part of living organisms didn't occur until Nicholas Steno (1638-1686) examined the triangular stony objects found on the island of Malta called glossopetra (tongue stones). These stones had been known since antiquity; Pliny the Elder concluded they fell from the sky. Steno was a Church educated anatomist and dissectionist who had the opportunity to study the carcass of a large shark. Steno concluded they looked like shark's teeth because that was what they were. The stones had been buried in mud and sand at the bottom of seas that were now dry land. The Seashell on the Mountaintop is a wonderful read about Steno's life and discoveries.

Steno's investigations of layered (sedimentary) rocks led him to set forth three guidelines he first proposed in Preliminary discourse to a dissertation on a solid body naturally contained within a solid (published 1669). The application of these principles became foundational to the science of geology:

• The Law of Superposition states that in an undisturbed sequence of rocks a layer is younger than the rocks it lays upon and older than those that rest upon it. (This ordering in sedimentary rocks is a consequence of the Laws of Gravity)
• The Principle of Original Horizontality states that rocks composed of sediment (particles) were deposited in essentially flat layers.
• The Principle of Lateral Continuity states that rock layers are continuous and can be correlated across valleys and underground.

Using superposition, Steno was able, for example, to distinguish the top from the bottom of individual layers even if the rocks were folded and overturned as is often the case in mountain ranges. Like da Vinci, Steno didn't know how the mountains had been raised. But like Thomas Burnet (1635-1715) in Sacred Theory of the Earth (published 1681) and William Whiston (1667-1752) in New Theory of the Earth (published 1696), probably Steno would have cited Gen 7:11.

Natural science (geology hadn't emerged as a separate discipline) was now firmly set on the path of systematic investigations that would result in powerful, evidence-based answers to the questions.