Carbon-14, or radiocarbon, is a radioactive isotope of carbon with a half-life of approximately 5,730 years. Because half of the remaining carbon-14 decays during each successive half-life, only a tiny fraction remains after tens of thousands of years. Eventually the amount becomes so small that radiocarbon dating reaches its practical measurement limit.
For this reason, conventional geology does not use carbon-14 to date dinosaur fossils believed to be tens of millions of years old, coal deposits assigned ages of hundreds of millions of years, or diamonds believed to be one to several billion years old.
Yet measurable carbon-14 has repeatedly been reported in materials considered far too old to contain their original radiocarbon.
That raises an obvious question: Why is measurable carbon-14 being detected in materials believed to be millions or even billions of years old?
CARBON-14 IN SUPPOSEDLY ANCIENT MATERIAL
Creationist geophysicist John Baumgardner surveyed published accelerator mass spectrometry (AMS) measurements of geological and fossil materials and argued that measurable ^14C appeared throughout samples conventionally assigned enormous ages. He later tested ten coal samples from different portions of the conventional geologic column. The samples produced an average measured radiocarbon concentration of approximately 0.25 percent modern carbon.¹
The RATE research project argued that this was significant because coal conventionally assigned ages of tens or hundreds of millions of years should contain none of its original carbon-14 essentially.
Critics respond that very small amounts of modern carbon can enter ancient samples during burial, chemical preparation, graphitization, handling, or AMS measurement. This is particularly important near the limits of radiocarbon detection because an extremely small amount of younger carbon can produce an apparently measurable radiocarbon age.²
In other words: the carbon-14 measurements themselves are not necessarily disputed. The major dispute concerns where that carbon-14 came from.
CARBON-14 REPORTED IN DINOSAUR BONES
Carbon-14 measurements have also been reported from dinosaur bones.
Young-earth researchers have submitted dinosaur bone fractions to radiocarbon laboratories and reported apparent radiocarbon ages generally in the tens of thousands of radiocarbon years rather than results indicating an infinite or completely ^14C-dead age.
This does not mean mainstream paleontologists accept those measurements as the actual ages of the dinosaurs.
The conventional explanation is that fossil bone is an open chemical system. Carbon can enter bone after burial through groundwater, recrystallization, microorganisms, humic substances, preservatives, and other sources. A 2019 study of Centrosaurus fossil bone, for example, found measurable relatively recent organic carbon and evidence of modern microbial activity within the fossil material.³
Researchers have therefore argued that radiocarbon detected in dinosaur bone can represent younger carbon that entered the fossil rather than carbon belonging to the original dinosaur.⁴
But that creates an important question worth investigating:
When carbon-14 is detected in a dinosaur fossil, how conclusively can researchers demonstrate that every measurable ^14C atom came from later contamination rather than from the original specimen?
That is the real scientific issue, not whether the instruments detected carbon-14.
CARBON-14 IN COAL
Coal provides another interesting case. The RATE project analyzed ten coal samples conventionally assigned ages ranging from tens to hundreds of millions of years and reported measurable ^14C in every sample.¹
Mainstream radiocarbon specialists have challenged the interpretation of these results. Coal can be contaminated by younger organic carbon, including mobile humic compounds, and extremely old samples are particularly sensitive to tiny amounts of contamination. Laboratory preparation itself can also introduce measurable carbon.²
The creationist argument, therefore, should not be that scientists are unaware of carbon-14 in coal. They are. The dispute is over whether all of the measured carbon-14 can adequately be explained by contamination and analytical background.
AND THEN THERE ARE DIAMONDS
Diamonds make the controversy especially interesting because their carbon is locked into an exceptionally strong crystalline structure.
The RATE researchers submitted natural diamonds for AMS analysis and reported very small but measurable ^14C signals. Some measurements corresponded, if interpreted as conventional radiocarbon ages, to approximately 55,000 years.¹
Subsequent measurements of unprocessed natural diamonds produced ^14C levels of roughly 0.005 to 0.03 percent modern carbon, levels that researchers interpreted as AMS instrument background, particularly carbon retained within the ion source from previous measurements. Critics therefore argue that the apparent carbon-14 in diamonds does not demonstrate that the diamonds themselves contain intrinsic ^14C.⁵
Creationist researchers dispute that interpretation and have argued that contamination and instrument background do not adequately explain all of the measurements.⁶
So once again, the important fact is not that a diamond has been scientifically dated to 55,000 years old. It has not. Rather, extremely small ^14C signals have been measured while scientists and creationists disagree over whether those signals originate within the diamonds or from the analytical process.
WHY THIS MATTERS
After 10 half-lives, only about 0.098% of the original carbon-14 remains.
After 20 half-lives, only about 0.000095% remains.
After 100,000 years, the theoretical amount of original ^14C would be extraordinarily small. After one million years, approximately 174 half-lives would have passed, leaving an effectively immeasurable fraction of the original carbon-14.
So if dinosaur bones are approximately 66–230 million years old, many coal deposits hundreds of millions of years old, and natural diamonds hundreds of millions to billions of years old, none of their original carbon-14 should remain today.
That point is not controversial.
What is controversial is the explanation for the tiny ^14C signals actually measured in some of these materials.
Conventional researchers argue that contamination, geological alteration, microbial activity, sample preparation, and instrument background explain these measurements.
Young-earth researchers argue that these explanations have not adequately accounted for every result and that measurable ^14C in supposedly ancient carbon-bearing materials deserves considerably more attention.
The carbon-14 measurements therefore do not, by themselves, prove that dinosaurs lived only thousands of years ago or that diamonds formed 6,000 years ago. But they do present a legitimate question that must be answered experimentally:
If these materials really are millions or billions of years old, can every detectable carbon-14 signal be conclusively demonstrated to come from contamination, geological processes, or instrument background rather than from the original material?
That is where the debate belongs.
Sources
¹ John R. Baumgardner, “Carbon-14 Evidence for a Recent Global Flood and a Young Earth,” Radioisotopes and the Age of the Earth, Volume II.
https://www.icr.org/i/pdf/technical/Carbon-14-Evidence-for-a-Recent-Global-Flood-and-a-Young-Earth.pdf
² R. E. Wood, C. Bronk Ramsey, and T. F. G. Higham, “Refining Background Corrections for Radiocarbon Dating of Bone Collagen at ORAU,” Radiocarbon 52 (2010): 600–611.
https://doi.org/10.1017/S003382220004563X
³ Evan T. Saitta et al., “Cretaceous Dinosaur Bone Contains Recent Organic Material and Provides an Environment Conducive to Microbial Communities,” eLife 8 (2019).
https://doi.org/10.7554/eLife.46205
⁴ Philip Senter, “Radiocarbon in Dinosaur Bones Revisited: Problems with Collagen,” The American Biology Teacher 84 (2022): 336–341.
https://doi.org/10.1525/abt.2022.84.6.336
⁵ Kirk Bertsche, “RATE’s Radiocarbon: Intrinsic or Contamination?” Discussion of AMS backgrounds and natural-diamond measurements.
https://talkorigins.org/faqs/rate-critique.html
⁶ John Baumgardner, “Are the RATE Results Caused by Contamination?” Answers in Genesis.
https://answersingenesis.org/geology/radiometric-dating/are-the-rate-results-caused-by-contamination/
