The Faith of Radiometric Dating
"How can creationists expect people to accept a young earth when science has proved through radiometric dating that the earth is billions of years old?"
This article addresses that question, which represents the thinking of a large number of people today.
Certainly the majority of scientists accept radiometric dating. And yet, there is really no scientific reason proving that radiometric dating is correct, and a number of evidences showing that it doesn't work. We'll discuss several of these. We'll find that faith in materialism, and rejection of any supernatural activity, is the foundation stone of radiometric analysis, even before any measurements are made. Most people, even the experts in the field, forget the assumptions on which radiometric dating is based.
There are basically two different kinds of radioactive dating methods. One is the Carbon-14 system used for dating fragments of once-living organisms. It's never used for non-organic samples, and almost never even attempted if the sample is thought to be much older than about 50,000 years. It furnishes some good evidences that creationists often use. But we won't discuss the C-14 method in this article.
The second broad category is sometimes called "heavy-metal dating," and includes Uranium-Thorium-Lead, Rubidium-Strontium, and Potassium- Argon systems. These are the methods that are commonly used on inorganic samples such as rocks, and that often give extremely long ages-millions or billions of years. Evolutionists often describe these methods as proving the ancient age of the earth and its strata. Creationists often criticize the methods as giving totally false results.
All of these dating methods begin with some radioactive isotope such as U-238, U-235, Th-232, K-40, or Rb-87. These are called the "mother" isotopes. These elements are naturally radioactive, that is, they spontaneously emit an alpha or a beta particle and, as a result, are transformed into some different element, called the "daughter" isotopes. For those who would like more details, these systems are briefly described in the boxes on the following pages. Nontechnical readers can skip the box-figures, however, without losing much.
The methods that give ancient ages produce almost as many "wrong" answers as "right" ones. The "correct" answer is chosen on the basis of stratigraphic sequences, that is, what kinds of fossils are buried nearby. Of course, the fossil dates depend on the assumption of evolution. And, of course, the public doesn't usually hear of these wrong answers.
This statement - that radiometric dates are "corrected" by reference to evolution-based index fossils - is hotly contested, but examination of the technical literature shows that it is true, in spite of what elementary textbooks say. Let's look at a number of examples.
The general public believes that radiometric results are consistent and thus demonstrably reliable. But the technical literature shows otherwise. John Woodmorappe did an extensive literature search, looking at 445 technical articles from 54 reputable geochronology and geology journals.1
These reports listed over 350 dates, measured by radiometric methods, that conflicted badly with the ages assigned to fossils found in these same strata. They covered "expected" ages ranging from 1 to >600 million years. In almost every case of a discrepancy, the fossil dates were accepted as correct. The radiometric dates were discarded. Woodmorappe quoted one researcher as saying:
In general, dates in the 'correct ball park' are assumed to be correct and are published, but those in disagreement with other data are seldom published nor are discrepancies fully explained.2
When these reports did discuss the possible causes of errors, they used words such as "possibly," "perhaps," "probably," "may have been," etc. Reasons given usually involved detrital intrusion, leakage or leaching of some of the isotopes in the sample, and sometimes the initial isotopic content of the sample. For K-Ar dates, it's easy to blame argon loss if the reported age is too short, or argon absorption if it's too long.
It is well known that argon, which is a gas, diffuses easily through rock, and there is no way of knowing whether that may have happened in any given case.
Errors are particularly bad with the K-Ar (potassium-argon) method. Studies have been made of submarine basalt rocks of known recent age near Hawaii. These came from the Kilauea volcano. The results ranged up to 22,000,000 years. Joan Engels wrote:
It is now well known that K-Ar ages obtained from different minerals in a single rock may be strikingly discordant.3
In 1972 Richard Leakey found a skull, near Lake Rudolf in Kenya, that he said was "virtually indistinguishable" from that of a modern human. Yet it was found beneath a layer of the volcanic KBS Tuff that had an accepted radiometric date of 2.6 MY (millions of years old). Leakey declared that the skull was 2.9 MY, and said that it "fits no previous models of human beginnings." It was named KNM-ER-1470 (for Kenya National Museum, East Rudolf, #1470).
Marvin Lubenow gives a good description of the ten years of controversy surrounding the dating of this skull.4
In the first attempt at dating the KBS Tuff, Fitch and Miller analyzed the raw rocks, and got dates ranging from 212 to 230 MY-the Triassic period, vastly older than expected. Because mammal bones had been found below this stratum, they said these dates were obviously in error because of "the possible presence of extraneous argon derived from inclusions of pre-existing rocks." Even though the rock looked good, anything older than 5 MY was obviously wrong in view of their knowledge of the "sequence of evolutionary development."
Meanwhile a team from the University of California at Berkeley, led by G.H. Curtis, analyzed several KBS pumice rocks and found some that were around 1.6 MY and some that were about 1.8 MY. Other measurements, some as low as 0.5 MY, were said to be anomalously young. These were explained as possible overprinting by an alkaline-rich hot water infusion.
Between 1969 and 1976 several teams made a number of radiometric measurements, and the results clustered around three ages-1.8 MY, 2.4 MY, and 2.6 MY. Each team criticized the others' techniques of rock sample selection. Most radiometric arguments were said to favor the 2.6 MY date, but the paleontological arguments favored the 1.8 MY date-(that is where the skull would best fit evolutionary theory). And final agreement came only after paleontologists had agreed on fossil correlations involving two species of extinct pigs. The final accepted date for the skull was 1.9 MY. Commenting on this method of selecting rock samples for radiometric dating, Lubenow asks:
The question arises, "How does one know when one has good samples for dating?" The only answer to that question is that "good" samples give dates that are in accord with evolutionary presuppositions. "Bad" samples are the ones that give dates not in conformity with evolutions classic illustration of circular reasoning.5
Grand Canyon Dating
Creationists have criticized many aspects of dating rocks by radioactivity, but have offered little real proof that the method is flawed. However, the
Institute for Creation Research is now in the early phases of getting such proof for igneous rock.6
"The purpose of this project," the ICR scientists write, "is to use the 'most reliable' radioactive isotope dating method (the 'isochron method') with the most accurate analytical measurement technique (the isotope dilution mass spectrograph technique) to establish the 'ages' of various Grand Canyon rocks."
The ICR scientists have engaged a licensed commercial geotechnical laboratory to help plan and oversee the project and prevent bias from influencing the results, and to submit rock samples to several qualified laboratories in a manner that will avoid subterfuge.
The Grand Canyon has many different rock strata and types. Everyone agrees that the Precambrian metamorphic rocks buried deep below the Canyon floor must be the oldest. These include the Trinity Gneiss, Elves Chasm Gneiss, and the Zoroaster Granite.
Everyone also agrees that the Quaternary lava flow on the Uinkaret Plateau is probably the youngest igneous deposit there. This came from a volcano, after all of the beds of sedimentary strata were laid down, and after the canyon was eroded. The lava flowed over the rim, and down the sides of the already eroded canyon.
Most conventional geologists believe that the deep gneisses and granites are more than 600 million years old, probably closer to 2,000 million years, and that the age of the Uinkaret Plateau basaltic lava flow should be measured in just thousands of years, because it's obviously younger than the sedimentary strata of the upper canyon walls. Thus, by comparing the accurately measured "ages" of a number of samples from these two regions, we should get an idea of the general reliability of radiometric methods.
The preliminary results look very interesting. But only the recent lava flow measurements had been completed at the time of my last report.
Several "model age" figures were obtained for this same set of recent rocks, and they were quite discordant (that is, they all disagreed with each other). The "more accurate" rubidium-strontium isochron age (see graph in Box 3) was reported to be 2.1 billion years.
But that age is clearly wrong. The lava being dated flowed over the edge of the already eroded canyon. Thus, the age "2.1 billion years" must be many thousands of times older than the actual age of the lava. This result alone should be enough to throw strong doubts on heavy-metal radiometric dating methods, but we must wait for the project's completion before too many conclusions are drawn.
Causes of Errors
There are several possible sources for the errors associated with radiometric dating. The main problems (beginning with those of least importance) are:
1. Accuracy of decay rates - most of these are thought to be known within a few percent and, if wrong, would have only a minor effect on dates.
2. Constancy of decay rates - most scientists believe these have been constant through the ages, although this can't be really known. But one of the early investigators, Prof. John Joly of Trinity College, Dublin, reported evidence showing variation.7 Barry Setterfield's report on possible variation of the speed of light also gives historical references to variations in decay rates over the last 300 years.8 But most scientists have been less than enthusiastic in their acceptance of this concept.
3. Neutron activation by unknown source - Professor Melvin Cook examined ores from a Katanga mine and found that they had no Pb-204 and no thorium, yet there was appreciable Pb-208! That apparently couldn't have been primordial, and couldn't have resulted from thorium decay. The only way it could be explained is by neutron activation of Pb-207. When Cook corrected for this, the calculated age was reduced from 600 million years to near modern.9 In most ores, it is not possible to see this effect so clearly, but this shows that some neutron flux, possibly from a supernova, must have had a strong influence, and this would probably be world-wide, affecting all rocks in a manner that couldn't be easily determined today.
4. Integrity of atoms in the rock - this is certainly a point of much concern to all chronologists, and is the most-cited reason for obvious errors in dating measurements. Uranium salts are water soluble, and most minerals are subject to unequal leaching of chemical components. Argon migrates unpredictably in and out of rocks. Hurley reported that radioactive components of granites lie on the surface of grains, and can easily be leached away. Zircon crystals have been dated by U-Pb methods, but ion microprobe studies have shown that the uranium and lead are embedded in different parts of the crystal structure. This shows that the Pb-206 actually could not have come from uranium decay; these dates must therefore be invalid.
5. By far the most important problem is the original isotopic content of the rock. How can we possibly know what the original material was? We'll see that this answer depends on a decision involving something that can't be proven - a decision made by faith.
Original Isotopic Material
The uniformitarian geologist must assume some initial concentration. If his choice is good, and the other error sources can be minimized, he could make an accurate age determination - provided his set of assumptions is correct. But his assumptions are always based on the theory of uniformitarianism - that is, that the earth and its rocks came into existence in a purely materialistic way, without supernatural intervention, a long time ago. If he then tries to use these results to prove that the earth is old and was not created, he's using circular logic. He is actually ruling out the possibility of a supernatural six-day creation before the measurement is made.
I took a geology course at my local college a few years ago. In the first class session, the instructor emphasized the importance of uniformitarian beliefs as the foundation of historical geology, and said something like this:
People used to believe in all sorts of catastrophes, caused by supernatural interventions. These folk-tales led people to believe that the earth was only a few thousand years old. Now, of course, we know such things never happened, and that the earth is much older than that. It's evolved slowly, over billions of years. This occurred according to the 'uniformitarian principle' - that all processes have always followed the same natural laws we observe today.
Notice the casual acceptance of the belief that the biblical account couldn't really be true. In his classic geochronology textbook, Henry Faul says:
If one assumes that the solar system condensed from a primordial cloud, it follows that the materials of planets, asteroids, and meteorites have a common origin. Iron meteorites contain some lead but only infinitesimal traces of uranium and thorium, and therefore the lead is uncontaminated by radiogenic lead and can be regarded as a good sample of primordial lead. Table 6-1 lists the isotopic composition of lead extracted from some iron meteorites. These data now can be used as (Pb207/Pb204)Ø and (Pb206/Pb204)Ø in the Houtermans equation, and all that remains to be found to permit a calculation of the age of the earth is a lead sample from a closed subsystem of well-known age.10
Notice Faul's starting-point-- - "if one assumes that the solar system condensed from a primordial cloud…" That means a purely naturalistic earth-origin, over a long period of time. Here he shows the belief common among almost all evolutionist scientists that the earth and the solar system evolved from a cloud of gas and dust, over a very long time, starting billions of years ago. From this basic belief, Faul argues that the original makeup of some of earth's chemicals must have been similar to what we can see today in meteorites.
This assumption is one of the main evidences used to determine the age of the earth and the lead isotope ratio in the composition of primordial rocks. But it is strongly based on belief in uniformitarianism and a naturalistic origin of the earth. Without this foundational belief, all of the various long-age dating measurements would be meaningless.
On the other hand, if the earth had been suddenly created (as the Bible says), the Creator could have made it any way He wanted to. He wouldn't have been constrained to follow any of man's rules - indeed, He has already demonstrated that. When He made the trees in the Garden of Eden, they immediately had fruit on them. When He made Adam and Eve, they were in a mature form, not tiny infants. We are told that He created these things with an appearance of age. Why couldn't He also have made rocks the same way? Why couldn't they have contained Lead-206 and Argon-40, so that they appeared "mature"? Scientists agree that Lead-204 must have been present since the earth's beginnings. Why couldn't most of the Lead-206, -207, and -208 also have originated in the same way?
Since a pre-historical act of God is not amenable to scientific investigation, and is therefore outside of the scientific method, many scientists exclude God from scientific possibility, and simply assume that God never intervened. They search for purely materialistic explanations as if they were the only scientifically acceptable choice. But this leads to a real problem. We see that radiogenic dating is not just based on physical measurements. Its foundation rests on a philosophical belief - one's belief in how the world came into existence.
We see that the question of "young-earth vs. ancient-earth" can be resolved only according to which of two foundational faiths one chooses.
If we choose faith in materialism and exclude the possibility of supernatural intervention, then it is reasonable to believe that the earth is billions of years old.
However, if we recognize a God who can and has intervened in His own creation, then it is reasonable to believe the biblical account, and an age of just thousands of years.
Neither of these choices is forced upon us by the physical evidence. Rather, we make the choice for philosophical reasons, then fit the evidences into one or the other foundational belief-system.
Many scientists, teachers, and much of the media, are very good spokesmen for the evolutionist's long-age beliefs. And many Christians have gone along with these scientists' "long-age-of-the-earth" statements, usually without realizing that they are based on naturalistic assumptions that completely rule out any sort of intervention by a creator God. They haven't recognized the fallacy of circular reasoning in these long-age beliefs. In this way, they've lost the foundation of their faith, needlessly.
Curtis Sewell, Jr worked for 44 years as an Electronics Engineer in the nuclear industry, beginning in the Manhattan Project of the U.S. Army during World War 11 (first atomic bomb). For five years he was Chief Engineer of Isotopes, Inc. Among his duties there were designing instrumentation for radio-chemical analysis of various specimens, including Carbon-14 dating systems. In 1988 he retired from Lawrence Livermore National Laboratory. He and his wife, Wanda, live in Livermore, California. They are active in their local church. They have three sons and seven grandchildren, who live elsewhere.
Copyright © 1994 Bible Science Newsletter. Creation Moments, Inc. PO Box 260 Zimmerman, MN 55398
1. John Woodmorappe, "Radiometric Geochronology Reappraised," in Creation Research Society Quarterly, Volume 16, September, 1979, pp. 102-129, 147.
2. Ibid., p. 114.
3. Joan C. Engels, "Effects of Sample Purity on Disco