Creationists make the claim that a global flood has messed up the precision of radiocarbon dating and hence, it cannot be relied upon. But if it is consistently cross-referenced by other methods, then the claim doesn't quite work.

I wonder if there were specific studies showing that let's say a supposed prehuman species dated at X years old are found surrounded by tools and rocks dated same X years old by argon-argon method or some such.

Examples of the claim:

What role might the Genesis Flood have played in the amount of carbon? The Flood would have buried large amounts of carbon from living organisms (plant and animal) to form today’s fossil fuels (coal, oil, etc.). The amount of fossil fuels indicates there must have been a vastly larger quantity of vegetation in existence prior to the Flood than exists today. This means that the biosphere just prior to the Flood might have had 500 times more carbon in living organisms than today. This would further dilute the amount of 14C and cause the 14C/12C ratio to be much smaller than today.

When the Flood is taken into account along with the decay of the magnetic field, it is reasonable to believe that the assumption of equilibrium is a false assumption.

Because of this false assumption, any age estimates using 14C prior to the Flood will give much older dates than the true age. Pre-Flood material would be dated at perhaps ten times the true age. ...

The average 14C estimated age for all the layers from these three time periods was approximately 50,000 years. However, using a more realistic pre-Flood 14C /12C ratio reduces that age to about 5,000 years. ...

An alternative interpretation of the carbon-14 data is that the earth experienced a global flood catastrophe which laid down most of the rock strata and fossils.
Answers in Genesis

AiG, a very popular Creationist website, has many other articles that say similar things.

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    can you qoute or link to what does "Great Flood has messed up the precision of radiocarbon method and hence, it cannot be relied upon." means ? it's hard to answer to general and wide arguments – Rsf Sep 28 '18 at 9:01
  • Yes, they are, but you could write books about this ;-) This question is better suited for Earth Science though, and maybe your answers are there already. I suggest you remove it here because it does not really have a notable claim – user22865 Sep 28 '18 at 9:02
  • I'm new here too, but it would help if you could include a link to a specific claim. But even if there is proof, their argument appears to be "My magic renders your science wrong". Any other dating method and any other science can be denied the same way. – Jerome Viveiros Sep 28 '18 at 10:02
  • The flood messing up radiocarbon is a separate thing, I'll post the question later. – Gregory Reshetniak Sep 28 '18 at 10:50

Carbon dating has been extensively cross-referenced by tree-ring dating (dendrochronology). Carbon dates that are corrected by tree-ring dating are called calibrated.

Tree-ring dating relies on the fact that trees have annual growth spurts and dormant period. As a result, each year the tree grows a new set of light and dark layers. These rings are easiest to see if the tree has been cut down. However, it is also possible to drill a core sample out of a living tree and inspect the rings that way.

The width of tree rings depends on the climate conditions during the year, and it is possible to match the rings of individual trees, so it is possible to create a pattern of rings that covers a much longer time span than the life of a single tree. It is possible to do this, not only with living trees, but also with trees that have died a long time ago. It's even possible to use pieces of wood that were used millennia ago, by comparing the rings with those of other trees.

As tree-ring dating is done by simple counting and comparing, it is inherently very accurate. If carbon dating is done on pieces of wood that have been dated that way, the two dates can be compared, and the C14 dating corrected as necessary. A calibration graph has been produced, going back over 40,000 years.

It should be noted that both tree-ring dating and radio carbon dating only work in the relatively recent past. For measurements of longer time periods, other methods need to be used. Some methods can be used to calibrate some of them. For example, ice cores in Antarctica have yearly layers going back about 50,000 years, and then below that dates going back hundreds of thousands of years are obtained by fitting chemical concentration history curves together between the ice core samples and other isotopic studies. For even longer time spans, there are many different isotopic age measurements, and where they overlap they can be used for cross-calibration.

In summary, while all measurements have some inherent uncertainty, these errors are in percentages. It is simply not feasible that our measurements could be wrong by a factor of more than 2 million (the difference between 6000 years and 13.8 billion years).


A couple of comments about the additional quoted text edited into the question.

This means that the biosphere just prior to the Flood might have had 500 times more carbon in living organisms than today.

That just means they need to lump everything dating from before the flood together, in order to make the flood hypothesis work. I'd like to see a world with 500 times more living matter than the present!

The average 14C estimated age for all the layers from these three time periods was approximately 50,000 years.

C14 dating is not usable for samples older than 50000 years, as there will be no C14 left in the sample. Hence, everything older will seem to have an age of about 50000 years: zero C14. That is why different methods are used for samples that are expected to be older.

When the Flood is taken into account along with the decay of the magnetic field

That is wishful thinking. The magnetic field fluctuates over both the long and short term. Even if the current decrease continues, that may mean no more than the fact that the field is reversing again, as it has done numerous times in the past. It's another of the misrepresentations of science that are common in creationist writing.

  • "As tree-ring dating is done by simple counting and comparing, it is inherently very accurate." Counting is inherently accurate. Comparing is inherently subjective. What exactly are they comparing to decide two rings from different trees were grown in the same year? – fredsbend Sep 28 '18 at 14:21
  • Ice cores in Antarctica only show layers up to about 50,000 years. Beyond that they use other methods than layer-counting. – elliot svensson Sep 28 '18 at 16:46
  • For the bottom part of the core (that is, for the period older than 50 kyr), we used several age control windows derived by comparison to the stacked marine isotope curve of Bassinot3, assuming a 4-kyr phase lag. These points are situated at Terminations II (1,738 m = 131.6 kyr), III (2,311 m =245.6 kyr), IV (2,593 m =338.6 kyr), VII (3,038 m =626.6 kyr) and VIII (3,119 m =717.6 kyr). Note that the age of identical events in this EDC2 chronology can differ, over their common parts, from the Vostok and Dome Fuji chronologies, because of slightly different best-fit parameters in the model. (1/2) – elliot svensson Sep 28 '18 at 16:51
  • Quoted from this: ir.canterbury.ac.nz/bitstream/handle/10092/14368/… , the 2006 EPICA report from Antarctica (2/2) – elliot svensson Sep 28 '18 at 16:57
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    There is a minor inaccuracy issue with tree ring dating: Certain growing conditions can cause two rings to be generated in one year, or cause the rings of two years to merge into one. (But the frequency of this is low, and it's easily compensated for by using several different samples, from different parts of the world.) – Daniel R Hicks Jun 19 '19 at 1:46

Known history

Because the range of times which can be measured by radiocarbon dating overlap with known history, it can be cross-checked with known history established by other means.

The original 1949 paper Age determinations by radiocarbon content: checks with samples of known age by J. R. Arnold and W. F. Libby measures the carbon-14 content of wood and relates them using two techniques. Tree-ring dating, as already covered.

The youngest sample used was furnished by Terah L. Smiley, of the University of Arizona Laboratory of Tree-Ring Research. It was a sample of Douglas fir excavated by Morris in the Red Rock Valley in 1931, the exact location being Room 6 of the Broken Flute Cave. The inner ring date is 530 A.D. and the cutting date is 623 A.D.

The redwood sample was furnished by Edmund Schulman, of the Laboratory of Tree-Ring Research at the University of Arizona. It was a fragment of the inner part of a Sequoia gigantea tree felled in 1874 A.D. It is known as the Centennial Stump and has been described by A. E. Douglass (4). The sample furnished carried a sequence of rings from 1031 to 928 B.C.

It then uses wood associated with historical figures of known age.

The next sample was furnished by John Wilson, of the Oriental Institute at the University of Chicago, and was a piece of wood from a mummiform coffin from Egypt, dated on stylistic grounds in the Ptolemaic period 332–30 B.C...

The next sample was furnished by Robert Braidwood, of the Oriental Institute, and consisted of two fragments of wood (Pinus halepensis) from the floor of a central room in a large hilani (palace) of the Syro-Hittite period in northwestern Syria. Prof. Braidwood dated the material between 725 and 625 B.C. from an imported Corinthian alabastron fragment, together with a great deal of historical evidence...

The fifth sample was a piece of deck board from the funerary boat of the Egyptian Sesostris III, which is displayed in the Chicago Natural History Museum. The wood probably is cedar of Lebanon. The sample was kindly furnished to us by the museum through the good offices of C. C. Gregg and Alex Spoehr. John Wilson dated the material as 1843 ±50 B.C.

The last sample, really being two samples, was described, with measurements, in an earlier publication (10). One of the two was from the tomb of Sneferu of Meydum (furnished by Froelich Rainey, of the University of Pennsylvania Museum in Philadelphia), which was 4575 ±75 years old. The other was from the tomb of Zoser at Sakkara (furnished by Ambrose Lansing, of the Metropolitan Museum in New York City), which was 4650 ±75 years old. The former sample was cypress wood and the latter acacia. The dates were given by John Wilson.

They all fit expectations rather well, especially for 1949.

enter image description here

Using this solid match, the paper concludes the basic assumptions behind radiocarbon dating are correct.

These results indicate that the two basic assumptions of the radiocarbon age determination method — namely, the constancy of the cosmic radiation intensity and the possibility of obtaining unaltered samples — are probably justified for wood up to 4600 years. The fact that the most ancient samples agree with the predicted value shows that the cosmic ray intensity has been constant to within about 10 percent for periods up to 20,000 years ago.

Radiometric dating

Carbon-14 is not the only means of dating by radioactivity. In the 1954 paper The Natural Distribution of Tritium Libby again demonstrates tritium can be used to date water and wine providing another cross-check.

The tritium contents of vintage wines appear to agree with the time elapsed since bottling, indicating the tritium abundances over the last eighteen years to have been essentially equal to the present ones.

There are a couple dozen methods of radiometric dating, each covering different but overlapping time scales, each able to cross-check each other.

Absolute and Relative dating

Tree rings, radiometric dating, and other techniques collectively are known as absolute dating where the goal is to determine how old an object is, within a margin of error. It's also the name of my reboot of The Dating Game I'm pitching to Spike.

Relative dating is the science of putting events in order without necessarily knowing when it happened (and nobody is allowed to pitch that dating show). A simple example, we know we landed a man on the Moon after television was invented because it was broadcast on television, but that doesn't tell us when we landed on the Moon, nor when television was invented.

One of the most famous, and most targeted by creationists, is using rock strata to establish relative dates. Everything in the same strata was laid down at the same time. Everything above was later, everything below was earlier. Creationists like to argue The Flood mixed this all up, but if so we should see very inconsistent results.

Relative and absolute dating can be used to cross-check each other. Absolute dating should produce the same order of events as indicated by relative dating, and they do. If The Flood mixed everything up we should not see any correlation.

Chronological dating

Collectively these techniques are called chronological dating. Many, many, many different techniques covering many different disciplines applied to different spans of time intermesh and overlap to cross-check each other and provide a robust historical timeline. While all measurements have error bars, none are so wide to accommodate creationism.

Creationist Shenanigans

When a scientist’s interpretation of data does not match the clear meaning of the text in the Bible, we should never reinterpret the Bible.

In contrast to science which collectively creates and refines models to match their observations, creationists try to bend observations to fit their pre-existing model; the Bible. Trying to force observations to match the literal Bible leads to cognitive dissonance and increasingly convoluted explanations.

Because of this cognitive dissonance, creationists will get dishonest. After doing a pretty good job of summing up Carbon-14 and its assumptions, it drops this whopper.

Dr. Willard Libby, the founder of the carbon-14 dating method, assumed this ratio to be constant. His reasoning was based on a belief in evolution, which assumes the earth must be billions of years old.

This is nonsense. As we have shown, Dr. Libby tested his assumptions and they checked out. Answers In Genesis chooses to ignore this. They also choose to ignore the 70 years of additional work confirming radiocarbon dating since.

Despite decades of cross-disciplinary work over nearly a century to build the chronological record, creationists like to ignore all that cross-checking and propose multiple scientific disciplines all got it completely wrong when it comes to history, when those same disciplines got everything else right. Often they will claim the techniques or entire disciplines are invalid because they produce results inconsistent with creationism, while using results from that same discipline to justify their own conclusions.

Answers in Genesis uses radiocarbon dating to make its point while claiming the people who do radiocarbon dating have interpreted it wrong for decades. Multiple disciplines have to be wrong for creationist young-Earth (I hesitate to legitimize it with the term) hypothesis to be correct. Biology, geology, astronomy, physics... disciplines which we rely on and prove themselves correct to mind-boggling levels of precision every day must be wrong. Not just a little wrong. Wildly, profoundly wrong but only in very specific ways necessary for creationism to be correct, but somehow incredibly accurate for everything else.

In contrast to the meticulous cross-checking done by scientists all over the world, creationists will focus on their perceived flaws in one technique in isolation as if it were the only evidence. Rarely do they attempt to offer a cohesive model to explain the complete body of observations, but instead propose different and often inconsistent models to match cherry-picked observations. Rarely do they attempt to cross-check their own work.

For example, Answers in Genesis quotes the RATE study by the Institute for Creation Research and you would be forgiven for wondering if they may be a bit biased. A rigorous investigation would cross-check the findings of the ICR to avoid explicit or implicit bias. They do not. Instead we are told to believe them and only them, and to ignore all the independent research because of the blanket excuse...

The objective was to gather data commonly ignored or censored by evolutionary standards of dating.

Answers In Genesis declares their conclusion up front, makes a pile of assumptions, dismisses well-established and independently verified science in the very specific ways necessary to support their argument, ignores inconvenient evidence, looks uncritically at their own evidence, and chains it all together with a bunch of weasel words to support their existing conclusion. "Indicates", "maybe", "might", "reasonable", "assumption", "perhaps".

The amount of fossil fuels indicates there must have been a vastly larger quantity of vegetation in existence prior to the Flood than exists today. This means that the biosphere just prior to the Flood might have had 500 times more carbon in living organisms than today.

Why 500 times more carbon? Why not 50? Why not 5000? Because they need radiocarbon dating to be off by a factor of 10.

When the Flood is taken into account along with the decay of the magnetic field, it is reasonable to believe that the assumption of equilibrium is a false assumption.

Answers in Genesis sandwiches an ICR quote between cherry-picked quotes from real scientists to support its argument. And it ignores Libby's own work verifying carbon-dating.

Because of this false assumption, any age estimates using 14C prior to the Flood will give much older dates than the true age. Pre-Flood material would be dated at perhaps ten times the true age.

Assumptions are piled onto assumptions. The amount of fossil fuels is only relevant to radiocarbon dating if we assume The Flood happened and somehow formed those fossil fuels by some unknown mechanism.

Because of this, and despite attempting to drape itself in the trappings of science, creationism is relegated to pseudoscience.


Before addressing the title of the question, I will first address the premise of the question:

Creationists make the claim that a global flood has messed up the precision of radiocarbon dating and hence, it cannot be relied upon. But if it is consistently cross-referenced by other methods, then the claim doesn't quite work.

If those same creationists claim that the flood was supernatural, and that which is supernatural isn't within the realm of natural, they could also argue that any other methods it would be cross referenced with would either be

  1. also affected by the supernatural flood or
  2. supernaturally placed there in some other way.

The same way they would argue a supernatural flood caused x to be different than the accepted laws of nature, they could just as easily argue that either the same, or similar, or different supernatural events caused any other cross referenced methods to be the way they are.

Their arguments aren't based on the scientific method, so using physical, natural evidence wouldn't apply to the the same way it would apply to a scientist, for example.

Now, to the question: Are results of carbon dating cross referenced by other methods?

The short answer is Yes

An article from nature.com details some examples of recent tree ring calibrations which are said to have changed the previously assumed dates (that were reached through radioactive dating) by different amounts, for example:

For the first time in seven years, the technique is due to be recalibrated using a slew of new data from around the world. The result could have implications for the estimated ages of many finds — such as Siberia’s oldest modern human fossils, which according to the latest calibrations are 1,000 years younger than previously thought.

So yes, it has and is being cross referenced with tree-ring methods, and according to this article, the new tree-ring research suggests the artifacts to be older than previously thought

That being said, the article further explains the need to cross-reference carbon dating with other methods, as carbon dating assumes the amounts of carbon in the atmosphere has always been consistent, but more recently with fossil fuels, it hasn't.

In their words:

The basis of radiocarbon dating is simple: all living things absorb carbon from the atmosphere and food sources around them, including a certain amount of natural, radioactive carbon-14. When the plant or animal dies, they stop absorbing, but the radioactive carbon that they’ve accumulated continues to decay. Measuring the amount left over gives an estimate as to how long something has been dead.

But this basic calculation assumes that the amount of carbon-14 in the environment has been constant in time and space — which it hasn’t. In recent decades, the burning of fossil fuel and tests of nuclear bombs have radically altered the amount of carbon-14 in the air, and there are non-anthropogenic wobbles going much further back. During planetary magnetic-field reversals, for example, more solar radiation enters the atmosphere, producing more carbon-14. The oceans also suck up carbon — a little more so in the Southern Hemisphere, where there is more ocean — and circulate it for centuries, further complicating things.

So they explain that other methods are needed to verify it. Although other answers on here have suggested tree ring evidence explicitly, the article says that more recently there have been other methods as well:

Since the 1960s, researchers have mainly done this recalibration with trees, counting annual rings to get calendar dates and matching those with measured radiocarbon dates. The oldest single tree for which this has been done, a bristlecone pine from California, was about 5,000 years old. By matching up the relative widths of rings from one tree to another, including from bogs and historic buildings, the tree record has now been pushed back to 13,910 years ago.

World's largest hoard of carbon dates goes global

Since 1998 there have been four official IntCal calibrations, adding in data from laminated lake and marine sediments, cave stalagmites and corals (which can be both radiocarbon dated and independently assessed using techniques such as radioactive thorium/uranium dating). In 2018, some stalagmites in Hulu Cave in China provided a datable record stretching back 54,000 years 1.

That footnote 1 in the article reads "Cheng, H. et al. Science 362, 1293–1297" which is quoted in sciencemag.org. As they say there:

An accurate, precise record of the carbon-14 (14C) content of the atmosphere is important for developing chronologies in climate change, archaeology, and many other disciplines. Cheng et al. provide a record that covers the full range of the 14C dating method (∼54,000 years), using paired measurements of 14C/12C and thorium-230 (230Th) ages from two stalagmites from Hulu Cave, China. The advantage of matching absolute 230Th ages and 14C/12C allowed the authors to fashion a seamless record from a single source with low uncertainties, particularly in the older sections.

So besides for tree ring dating, they also use the "thorium-230Th" method, which is slightly different than Carbon-12 and Carbon-14 methods.

They explain more in the article the necessities of cross referencing carbon 12-14 models with others (not necessarily tree ring models), in their words:

Libby pioneered the 14C dating method (1), which revolutionized a number of scientific disciplines, most notably archeology and climatology. However, variations in atmospheric 14C, likely caused by changes in the shielding of cosmic rays induced by the Earth’s and Sun’s magnetic fields and/or the redistribution of 14C among different carbon reservoirs, were soon recognized (2). These changes necessitate the calibration of 14C ages against a calendar time scale. A precise and accurate 14C calibration is considered the Holy Grail of radiocarbon dating.

Our ability to calibrate the 14C time scale has been limited by our ability to establish the absolute age of a material that contains information about atmospheric 14C/12C. By the late 1980s, the most recent portion of the 14C time scale [last ~10 thousand years (ka)] was calibrated extremely precisely using dendrochronology. The development of mass spectrometric 230Th dating methods (3) and their continued refinement (4) opened up the possibility of extending the calibration much deeper in time, led to the first large extension of the calibration well back into the Pleistocene (5), and ultimately has led to the current contribution. However, the 230Th dating approach has its own constraints. Corals, which are good materials for 230Th dating, do not accumulate continuously over thousands of years and are difficult to collect since those in the time range of interest are now largely submerged. Stalagmites, which can be excellent choices for 230Th dating, typically contain a significant fraction of carbon ultimately derived from limestone bedrock, which is essentially 14C-free. Stalagmite-based calibrations must therefore correct for a dead carbon fraction (DCF), which can be large and variable and is typically the main hurdle in such efforts (6, 7).

Southon et al. (8) demonstrated that the DCF in one Hulu Cave (32°30ʹN, 119°10ʹE) stalagmite, H82, was unusually small and stable, allowing a precise and accurate 14C calibration in the 26.8 to 10.6 ka B.P. (before the present; “present” is 1950 CE) interval (fig. S1). Here, we show that older Hulu Cave stalagmites, MSD and MSL, have similarly low and stable DCFs (Figs. 1 and 2), which allow for precise and accurate 14C calibration for the remainder of the 14C time scale back to ~54 ka B.P.

So they mention the 230Th method, but explain how that alone also has various inconsistencies, since the materials they collect it from, such as coral, have not been demonstrated to take it in consistently for thousands of years

But besides for that various sets of data (using the four methods mention there) from a cave in China seem to show similar, yet slightly different results. Graph

Basically, based on the data from the Hulu cave from the other methods, they attempt to put together the relative ages and resolve the previous uncertainties they had:

Considering the full record, there is a general correspondence with the latest IntCal compilation (17) (Figs. 1 and 2) within fairly large uncertainties, confirming the general validity of the compilation. However, for the portion older than 30 ka B.P., clear differences emerge. The Hulu record has less uncertainty and resolves previously unknown fine-scale structure. Between 33.5 and 42.5 ka B.P., the Hulu record indicates larger offsets between 230Th ages and 14C ages than IntCal13, with offsets between the records as high as 1 ka, corresponding to a higher Δ14C by as much as 170‰ as recorded at Hulu. Conversely, from 42.5 ka B.P. to the end of the IntCal curve at 50 ka B.P., **the Hulu record indicates smaller offsets between 230Th and 14C ages, by ~1 ka, which corresponds to ~140‰ lower Δ14C. **From 50 to 54 ka B.P., the Hulu curve indicates similar though nominally higher Δ14C than during the subsequent few millennia. Another notable difference is the sharper and higher amplitude increase in Δ14C around 42.5 ka B.P. A notable similarity is the lack of a prominent low Δ14C excursion around 31 ka B.P. This low, present in Cariaco sediment and Bahamas speleothem datasets (7, 18), was omitted from IntCal13 because of its absence from the Lake Suigetsu record (19). The Hulu data support this omission.

They then explain some of the irregularities with the other methods and 14C alone, and conclude they usually need all of them together to get a somewhat consistent picture:

14C ages are generally less than calendar ages throughout the full record, reaching a maximum offset of ~5200 years between ~39.3 and ~40.8 ka B.P. (Fig. 1).** The offset is largely due to higher atmospheric Δ14C, although there is also a progressive offset of 2.83% of the age due to the use of the Libby half-life in calculating the 14C age. **Between 54 and 43 ka B.P., **Δ14C values range between 0 and 300‰, then increase sharply to values exceeding 600‰ by 42 ka B.P. **(Fig. 2). High values continue until 38.8 ka B.P., reaching the highest values in the full record of 700‰ at 40.8 and 39.3 ka B.P. Between 38.8 and 38.0 ka B.P., Δ14C decreases sharply to values around 500%. Between 38.0 and 25.0 ka B.P., Δ14C values exhibit millennial-scale variability with highs around 600% and lows around 400%. Notable is a relative high of about 600% at 33.8 ka B.P. From 25.0 ka B.P. to the mid-19th century (as previously known), Δ14C values gradually diminish from around 500% to 0, with significant changes in slope between 16 and 11 ka B.P.

The new data provide critical constraints on the causes of changes in Δ14C during the last 54 ka. The millennial-scale pattern of Δ14C variations (Fig. 3) has similarities to the geomagnetic record (Virtual Axial Dipole Moment data) (20), suggesting that changes in shielding of cosmic rays by the geomagnetic field are responsible for much of the millennial-scale variation in Δ14C. Of note is the coincidence within tight age uncertainties between the abrupt increase in Hulu Δ14C and the onset of the Laschamp magnetic excursion at ~42.3 ka B.P. (21), as well as between the period of weakest geomagnetic field during the Laschamp (~41.1 ka B.P.) (21), which correlates with the highest Δ14C values over the past 54 ka. This suggests that the Laschamp is responsible for both of these features. Additionally, a second prominent peak in the Hulu record at ~34 ka B.P. is consistent with the timing of the Mono Lake excursion (22), suggesting that this excursion is responsible for the Δ14C peak (Fig. 3).

They then provide a chart showing the different ages and dates arrived at using the 4 different methods.

They explain possibilities for the inconsistencies:

The broad lowering of Δ14C throughout this interval **could plausibly result from progressively increasing ocean ventilation. **All other factors being equal, the shorter the mixing time, the less time for 14C to decay, the more 14C in deep waters and, by mass balance, the lower the Δ14C of the atmosphere. Presuming an average deep water age of 1000 years at 11 ka B.P. and a 60:1 ratio of deep water to atmospheric carbon, the lowering of atmospheric Δ14C over this time period can be explained by a progressive shift in deep water age from about 3000 years at 25 ka B.P. to the assumed 1000-year value at 11 ka B.P.

They conclude that they are still working on verifying it:

There is some support for the inference of increasing ventilation with time, as observations indicate that the deep Southern Ocean and South Pacific were poorly ventilated at the last glacial maximum (32–34). Deep ocean Δ14C data for times since the last glacial maximum (35) do not clearly resolve pre-Holocene from Holocene ventilation ages, but they also do not preclude large pre-Holocene ventilation ages. Thus, while it is likely that deep ocean ventilation change accounts for a portion of the residual 25 to 11 ka B.P. Δ14C drop, it is still not clear whether it can account for the full drop. Further work is needed to close the loop on this critical issue.

So it would seem from that article that there are four general methods they use, which give slightly different results (that they are still working to resolve) which are

  1. Δ14C residual "Hulu-model" which itself is divided into a) "Dust flux" (mg m-2 yr-1) and b) CO2 (ppmv)
  2. Δ14C "residual-detrended" hulu model
  3. Hulu 18O (VPDB) and
  4. NGRIP 18O (SMOW)

as referenced in the above linked image and explained in the article, as well as this image which includes the tree ring method

and explained in the beginning:

Fig. 1 Hulu speleothem 14C versus 230Th ages and comparison between Hulu and IntCal13 14C ages. (A) Hulu [olive-brown, H82 (8); blue, MSD, and green, MSL (this study), and IntCal13 14C (17)] vs. 230Th ages. 14C error bars are 1σ. For clarity, uncertainties in IntCal13 are not shown. The floating tree ring Δ14C datasets (purple) (14, 15) are tuned to the Hulu 14C record (11). The red square (1σ) is the independent data point based on 14C measurements on wood associated with the Ar-Ar dated Campanian Ignimbrite (13). (B) 14C age difference (black) between Hulu dataset and IntCal13 (17). The gray envelope shows the uncertainty (1σ). Hulu 14C ages are corrected for the DCF (450 ± 70 years) (8). (C) Calendar age minus IntCal13 (red)/Hulu (blue) 14C age. The light blue envelope shows the uncertainty (1σ). The three Hulu sample datasets replicate over contemporary growth periods. Hulu Cave 14C data are consistent with IntCal13 between ~10.6 and 33.3 ka B.P. but lower in 14C ages between ~33.3 and 42 ka B.P. and higher between 42 and 53 ka B.P.

As well as Figure 2 that they explain:

Fig. 2 Comparison of Hulu Δ14C data with IntCal13. Hulu Δ14C data are shown with error bars with the same color codes as in Fig. 1. IntCal13 and its dataset (17) are shown in the gray envelope and gray bars. 14C error bars are 1σ. Hulu data overlap with IntCal13 between ~10.6 and 33.3 ka B.P.; however, there are substantial offsets, particularly before 30 ka B.P., and the Hulu record exhibits substantial previously unknown millennial-scale structure. The purple error bars and red square are the floating tree ring series and Campanian Ignimbrite data, as in Fig. 1.

So there are several uncertainties with these methods and much of it is still being worked on, but even if there weren't the young earth creationists will just tell you that the trees were created to look old in the first place, similarly to how a miraculous flood would have altered the carbon-14 data, so even if the other methods were consistent, that wouldn't disprove anything to them, as the question seems to suggest it would.


According to this chart, writing is contemporary to about 5kya, paleomagnetic, dendrochronolgy, radiocarbon, and amino acid racemization are contemporary to more than 10kya (generally accepted as an upper bound for YEC age), and thermoluninescence, electron spin resonance, and fission track are nearly contemporary to more than kya. If we take out paleomagnetic as it is a relative dating technique, that leaves four methods from contemporary to 5kya and six methods from near contemporary to 10kya. And if we're merely looking for dating methods that yield a result that's inconsistent with YEC, there are quite a few more.

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