Misconceptions about the Geologic Column – Part III

Continuing from the previous post regarding the misconceptions people generally have about geology and the geologic column.
    Now that we understand these starting points, we can take a closer look at the geologic record. As stated earlier, there is no place on earth where we can find every rock layer in a continuous sequence. The geologic column presented in textbooks is a composite of many smaller columns that can be identified from direct observation. 
Geologists and other earth scientists often refer to the rock record. This record is nothing more than the rocks that currently exist. The rock record does not show a tidy, orderly progression of geologic event. Rock formation  are eroded, buried torn apart, melted, squashed together, even turned upside down, and deposition in the geological process in which sediments, soil and rocks are added to a landform or mass.

Three eras of deposition and two discordancies are visible in this highway cut in the Netherlands

    However, the presence of a general order in the rock record is undeniable. Questions about the nature of the geologic column ultimately center on the origin of the rock record. Those who start with a biblical view see the layers as evidence supporting the Creation Week and the global Flood described in Genesis (Genesis 1–2 and 6–9 respectively). Those who reject the clear teaching of the Bible interpret the rock record as a 4.55 billion year history of the earth.
    There are many misconceptions about the nature of the geologic record and the geologic column used to represent the rock record. It helps to understand how the standard geologic column was constructed.
    The concept of mapping and explaining rock layers began with Nicolaus Steno, who published on the geology of Tuscany in 1669. Steno set forth the basic rules followed by geologists today when examining field evidence. He actually based his reasoning on the biblical account of the Flood and accepted that the earth was only about 6,000 plus 7,000 for a total of 13,000 years old—a Bible–believing creationist laid the foundation for modern geology!
    His Law of Superposition states that upper layers were deposited after the lower layers. The Principle of Original Horizontality states that sedimentary layers are deposited in flat layers that may later be disturbed. The Principle of Cross-Cutting Relationships states that a fault or intrusion must be younger than the layers it affects. All of these ideas can be used by both uniformitarian and biblical geologists to identify the relative ages of sediments.
    During that same period, other geologists and theologians used the account of the Flood to understand the layers of sediment and the fossils contained in them. The understanding of the day was based on the idea that a major catastrophe had shaped the globe.

Creationists believe Noah's Flood caused the vast majority of fossils and rock formation; Uniformitarianism believe that small, local catastrophes cause disruption in isolated areas of the rock, fauna and flora formations

    The definition of Catastrophism is: “The doctrine that changes in the geologic record are a result of physical processes operating at rates that are dramatically higher than are observed today” (Note: although the biblical view is one of many catastrophist views, not all catastrophist views are biblical).
    Contrary to the catastrophist view, James Hutton and Charles Lyell argued that the present is the key to the past. They viewed the layers of sediments as products of vast ages of time. The processes forming and eroding rocks today are the same as they have always been.
    Geology was divided between catastrophists who believed many large-scale floods had shaped earth’s rock record and Uniformitarians who believed in gradual processes. Eventually, the ideas of Hutton and Lyell came to dominate geologic thinking, and the Bible was thrown out of geology despite the efforts of some geologists who remained faithful to Scripture. Sadly, many theologians also adopted old-earth ideas and reinterpreted Scripture to align with the thinking of man.
    Thus we find Uniformitarianism establishing, defined as: “The doctrine that present-day processes acting at similar rates as observed today account for the change evident in the geologic record.”
    William Smith first used the similarity of fossils to construct detailed geologic maps across wide areas. He used fossils to map and correlate rock layers and constructed the first geologic map of England and Wales in 1815. Smith was a creationist who believed in the old-earth view now known as progressive creationism. By the early 1800s the idea of an old earth was popular, though the idea of a global flood was still used to explain many geologic deposits.
    The standard geologic column was constructed by combining descriptions of local areas to form a composite record. By 1885 the finer divisions of the column had been identified based on the principles established by Steno, Smith, and Lyell. These ideas were also beginning to impact the study of biology, and Lyell’s long-age ideas played a major role in Darwin’s development of the theory of biological evolution over vast geologic eras.

Index fossils played an important role in the development of the geologic column. The idea that life became increasingly complex over time, whether by some evolutionary force or continuous creation by God, was used to analyze the fossils in the rock layers. It was assumed that by identifying the order of fossil succession, the layers could be correlated from one region to the next. Index fossils are still one of the major indicators of the age of a given layer. Shelled creatures such as ammonites and mollusks are the most commonly used index fossils.
    The pictures of creatures used in traditional geologic column diagrams are indicative of index fossils. Such fossils are thought to have first appeared in their particular strata, and to be indicative of the age of that stratum. One would expect such fossils to appear in layers higher than that, for which they are indices. This complicates the dating process. Dr. Gary Parker, for example, reports on the finding of a fossilized clam, which supposedly indexes strata which are millions of years old, yet it contains soft tissue, which cannot have survived for so long.
    Despite the confidence in index fossils, there is much criticism of their use—from both creationists and evolutionists. Slight differences in shell shape or structure are used to assign the shell to a new species, despite the variation apparent within a single living species today.
    Another problem with index fossils is that, rather than being proof of evolution, evolution is already assumed to have occurred. The changes in features in index fossils of different periods are assumed to be caused by evolution, and the presence of different organisms in different periods is then used to support biological evolution. This is a case of using an assumption to prove the assumption is true circular reasoning by any measure.

A body of rock defined by its fossil content of a biozone fossil in biostratigraphy

The definition of an Index Fossil is: “a fossil that is useful for dating and correlating the strata in which it is found, that is, a widely distributed fossil, of narrow range in time, regarded as characteristic of a given geological formation, used especially in determining the age of related formations.” Since these fossils delimit a geological zone, they are also called “zone fossils,” and also as guide fossils or indicator fossils as they are used to define and identify geologic periods or faunal stages. These fossils were short-lived in geological terms, lasting a few hundred thousand years. It is assumed that they existed in the same time frame as the sediment in which they are found, thus confirming that the sediments in question—different sediments may look different depending on the condition under which they were laid down—were deposited within that narrow time period.
    Ammonites, which have a fossil shell that usually takes the form of plainspirals fit these demands well, and are the best-known fossils that have been widely used for the purpose of index fossils. The series of deposits that spans the occurrence of a particular index fossil, is often referred to as that fossil's zone, enabling to relate different faunas through time. An example would be to say that Mesolenellus hyperborean occurs in the late Nevadella-zone.
(See the next post, “Misconceptions about the Geologic Column – Part IV,” for more on how people misunderstand the geologic column and geology in general and its impact on the believability of the young Earth age of 13,000 years)