Author : A.E. Proctor
The faith of many has been shaken by the assertion the data observed in nature indicates a very great age for the earth. Such a great age is in direct conflict with the teachings of the Bible that the Creation and Flood of Noah occurred within a relatively short period before our own time. Today we are indoctrinated with the idea that the earth is of such a great age that every time we see the exposed geologic deposits of this earth, the thought come to mind, “It took millions of years for these layers of rock to be built up.” The assertion that modern geological technology has been able to measure these formations to be millions and even billions of years old is accepted even by those who wish to believe in God’s word and the account of the creation as found in Genesis.
There are a number of methods used to determine the age of soil and rock samples. Some methods are used as a check on the accuracy of other tests, so that it seems that it would be impossible for an error of any kind to be found in such age determinations. I cannot describe all the tests now being used in an article of this size, so I will limit my discussion to an examination of the two major methods. To do this, we need to understand some history of how present dating methods came about.
William Smith was an English canal builder who had opportunity to examine much of the subsurface strata in many parts of his native country during the early 1800’s. He collected sample fossils from many different layers of rock and soil, and kept careful records of the area of Great Britain where the sample was located, the depth of the layer of rock in which the fossil was found, and the types of strata above and below the fossil. After a lengthy study of the fossils he had collected, Smith noted that similar fossils were generally found in the same strata throughout England. He also noticed that smaller and less complex fossils tended to be found in lower layers of the geologic column, and larger and more complex organic remains were found in higher layers. On the basis of these observations, Smith advocated the concept that certain fossils always occurred in the same strata and that the strata were always found in the same sequence. These particular fossils became known as “Index Fossils.” James Hutton, a geologist who was a contemporary of Smith, taught that the layers of rock had been built up over long periods of time. Using Hutton’s theory, Smith set up a system of groups of strata on the basis of the fossils they contained and used these groups to define the age of the earth. The groups subsequently became known as Periods. (In later times, others consolidated the Periods into Eras, and subdivided the Periods into Epochs.) Although he did not advance the idea, it was implicit in Smith’s theory that the sequence of fossils found as the observer moved from the bottom to the top of the geologic column changed from simple to more complex forms.
In the middle part of the 19th century, Charles Lyell began to assert that all strata studied by Smith and Hutton could have been formed by existing natural forces if they were given enough time, and that the then prevailing theory that the strata were deposited by the flood of Noah and other floods was not necessary to explain the existence of many layers of rock in the earth’s strata. Lyell also asserted physical conditions as they were on the earth at that time had never changed throughout the earth’s existence. These teachings led to a great deal of debate between his followers and those who held that all earth strata resulted from many catastrophes, primarily the flood of Noah.
Those who opposed Lyell became known as followers of Catastrophism. In time, Lyell’s teachings became known as Uniformitarianism. Unfortunately, religious division and differing interpretations of the book of Genesis led to equally sharp debates among those who opposed Lyell. As a result of this confusion, many scholars and other intellectual men became convinced that those who taught Catastrophism were in general an uneducated group who possessed little, if any, credibility. A large number of educated men then began to accept Lyell’s teachings. The final blow to Catastrophism, in the view of many, came when Darwin published his theory of evolution. Using the assumption that organisms evolve from simpler to more complex forms, several independent scholars adapted William Smith’s concept of index fossils to the evolutionary theories of Darwin, and developed the so called “Law of Faunal Succession.” This “law” became the core of Uniformitarianism, and subsequently, the philosophical foundation of modern Historical Geology and Paleontology.
During the early part of the 20th century, most scholars abandoned Lyell’s claim that no catastrophes have occurred during the existence of the earth. Earthquakes of different magnitudes have split and fractured strata in many locations. The concept of “Ice Ages” has been advanced to explain findings of large mammals found completely frozen in arctic regions, and the existence of the Great Lakes in North America. Local floods have eroded and redeposited both strata and the fossils found in them. Although rejecting parts of Lyell because the theory did not fit the data observed in nature, modern geologists have retained the concept of index fossils and faunal succession in all geological dating systems.
Simply put, the system of dating by index fossils came about when agreement was reached among scholars of the late 19th century upon the ages of certain groups of index fossils. From that time on, position of the rock in layers of strata, or in the depth in which it was found became irrelevant. The only thing that was of use to determine the age of any given strata was the groups of index fossils found in it. Subsequent discovery of strata in other locations on earth with “young” index fossils many feet under “old” index fossils did not and could not change the concept. If “old” rock was found on top of “young” rock some other explanation had to be developed. In the case of the Wyoming overthrust belt in North America, it had to be assumed that hundreds of square miles of “old” rock had in some way moved (leaped?) over hundreds of square miles of “young” rock without leaving traces of movement at the interface of the “young” and “old” strata. Much study has been devoted to the characteristics of this formation, but no truly satisfactory explanation outside of the Creation Model has ever been advanced to explain it.
Continuing work in biology has also raised many questions as the absolute accuracy of the relative ages of the index fossils, and the assumed lines of descent. Many fossils in the index are those of animals which were living during Smith’s lifetime and some fossils are from animals assumed to be extinct, but the animal was subsequently found alive in the 20th century. The student of the Bible should be aware that ultimately all systems of dating depend upon the theory of index fossils, and faunal succession. The proofs most often cited for a great age of the earth can be grouped under the general classification of geological radioactivity measurement.
To understand the measurement of age by radioactive decay requires an understanding of the term “half life.” Half life is the span of time required for half the mass of a radioactive substance to decay into a less radioactive substance. At the end of the period of time known as the half life, one-half of the original sample will be original material and one-half will be the product of radioactive decay.
In general, uranium will, over a number of years, decay into lead. It does not do so directly, but decays into less radioactive isotopes and these isotopes in turn decay into less radioactive isotopes until all becomes non-radioactive lead. The time sequence for this decay process is measurable in the laboratory, and the half life of most elements is well established.
If a scientist is given a sample of what was once pure uranium, he is able, by measurement of the relative mass of each isotope, to determine when in time the sample was 100 percent pure uranium. If the sample was not 100 percent uranium in the beginning, but contained some lead or other isotope of uranium, he cannot measure the age of the sample, but can only calculate the point in time when the sample would have been 100 percent uranium. In other words, the rate of decay can be determined very precisely, but the age of any sample can be determined only if you know the type and amounts of each decay product in the sample at the point in time you wish to verify. You have a system of fantastic accuracy, but it isn’t useful unless you can calibrate it. A number of radioactive elements have differing decay rates and end products. If you can find a sample with different radioactive elements it is possible to make a cross check from the decay products of one element to another; this will give a better number for the half life, but it brings you no closer to the actual age of the sample. It is the calibration process where all radioactive measurement systems of age determination fail.
To properly use the measurement technique, we must have a sample containing a radioactive element whose age is known from other systems of measurement. It is then possible to calculate the amount of original lead (called anomalous lead) in the sample. If we then assume that other samples have the same amounts of anomalous lead, and assume that the forces of nature have not increased or decreased the amount of radioactive isotopes through leeching or other known processes, we can measure the ratio of the age of a given sample to the age of our calibration sample. The accuracy of any such measurement comes down to the accuracy of the estimate of age of our calibration sample.
The problem is where do we get our calibration sample of known age? Why the Paleontologist will be happy to provide it. But how does he know how many millions of years old his sample is? He dates it by the use of index fossils in the strata where the sample was taken. In the calibration process, any data from the measurements which would indicate thousands rather than millions of years would be discarded as irrelevant or flawed because the Paleontologist knows the samples are so many million years old. It is then understandable that the radioactive measurement would tend to “prove” that which is already assumed. There are many other objections to the methods and techniques of radioactive dating, but for the purpose of this article I simply wish to point out that a system of measurement cannot be calibrated with the data it is supposed to verify.
In time, the science of Biology may abandon the theory of evolution, but the Christian who wishes to enter the field of Historical Geology or Paleontology must keep in mind that the very existence of these fields of study not only assume the existence of evolution, but demand it.
