The literature

This page exists so that nobody has to take the rest of the article on trust.  Every source it rests on is listed here with what it actually measured, the access route that worked, and which way it cuts.

The argon in the air is a single number that integrates every potassium-40 decay the Earth has ever degassed. That makes it a different kind of test from any rock date. A rock can be reset, contaminated, or picked badly. The atmosphere cannot be reset, and there is only one of it.

This catalogue is deliberately not a reading list of things that agree with this site. The strongest sources here run against the young-earth position, and they are tagged that way. A reader who wants only the material that hurts the argument can filter for undercuts and read those first.

How to read an entry

Measurement or model. The atmospheric argon inventory is close to a pure measurement: the mass of the atmosphere, the mole fraction of argon in dry air, and the ⁴⁰Ar/³⁶Ar ratio are all instrument readings. The Earth's total potassium content is a model, and its uncertainty is the widest joint in the whole argument. Both matter. They are not the same kind of thing, and the entries say which is which.

Access route. Several of these are paywalled and one is a printdisabled book. The route that actually worked is recorded so nobody repeats the hunt. Where nothing worked, every failed route is listed under NOT OBTAINED in research/_brief.md.

Direction. Whether the source supports, undercuts, or complicates the young-earth position — assigned by what the source shows, not by what its author believes.

Camp. Disclosure, not a verdict.

Field definitions

1. The atmospheric inventory itself

Bender, Barnett, Dreyfus, Jouzel & Porcelli 2008 — "The contemporary degassing rate of ⁴⁰Ar from the solid Earth"

Proceedings of the National Academy of Sciences 105(24):8232–8237. doi:10.1073/pnas.0711679105. topic: inventory, degassing · camp: mainstream · type: measurement · access: OA (PMC2448820) · direction: undercuts

The single most important source in this file. It states the whole argument in its own abstract and then measures the one quantity that had never been measured.

Measured: the paleoatmospheric ⁴⁰Ar/³⁸Ar ratio in air trapped in the Vostok and EPICA Dome C ice cores back to about 779 ka, by mass spectrometry, corrected for gravitational fractionation in the firn using the ³⁸Ar/³⁶Ar ratio. From the slope they get a modern ⁴⁰Ar outgassing rate of 1.1 ± 0.1 × 10⁸ mol/yr (p. 8233). Table 2 (p. 8234) gives the atmospheric argon content as 1.65 × 10¹⁸ mol.

Two verbatim statements, both on p. 8232:

The ⁴⁰Ar inventory of the atmosphere equals total ⁴⁰Ar outgassing during Earth history.

It is well recognized that the atmospheric inventory comprises approximately half of the total ⁴⁰Ar produced by potassium decay over Earth history, assuming the canonical value of 240 ppm for the K content of the bulk silicate Earth (1).

Reference (1) is Allègre, Hofmann & O'Nions 1996. The paper also records the live mainstream dispute honestly: Davies and Lassiter propose a bulk-silicate-Earth potassium concentration of ~150 ppm rather than 240, precisely because 240 ppm leaves an awkward undegassed remainder to hide (p. 8232).

Route that worked: curl on europepmc.org/articles/PMC2448820?pdf=render. The pmc.ncbi.nlm.nih.gov/.../pdf/ route returns HTML, not the PDF.

Ozima & Podosek 2002 — Noble Gas Geochemistry, 2nd edition

Cambridge University Press. archive.org identifier noblegasgeochemi0000ojim. topic: inventory, degassing · camp: mainstream · type: book · access: printdisabled-searchinside · direction: undercuts

The standard graduate text. Three passages carry the argument.

p. 237 — the atmospheric inventory, and the reason it looks crustal:

the amount of ⁴⁰Ar in the atmosphere (1.7 × 10¹⁸ moles) is close to the amount of radiogenic ⁴⁰Ar (ca. 1 × 10¹⁸ moles), which can be produced by K in the crust (about 1%; cf. Taylor & McLennan, 1985) over 4.5 Ga.

p. 219 — the degassing fraction:

from a simple consideration of ⁴⁰Ar budget in the Earth, we have shown that more than half of radiogenic ⁴⁰Ar has been degassed from mantle to the atmosphere (Section 6.6).

p. 215 — the bulk-Earth potassium estimate, attributed to Allègre, Hofmann & O'Nions 1996: whole-Earth K ≈ 250 ppm, from U = 20 ppb and K/U = 12,700; upper-mantle K ≈ 50 ppm.

Access, and the locator trap. This item is in the printdisabled collection: no borrow button, no OCR derivatives. It is fully readable in whole paragraphs through bin/iapdsearch.py. Leaf number = printed page + 18. Anchored twice on the OCR running heads — leaf 184 prints "166 The Mantle" and leaf 204 prints "186 The Mantle" — and cross-checked against the public BookReaderJSIA.php page map, which gives leaf 237 → p. 219 and leaf 255 → p. 237. Do not guess this offset.

Trenberth & Smith 2005 — "The mass of the atmosphere: a constraint on global analyses"

Journal of Climate 18:864–875. topic: inventory · camp: mainstream · type: measurement · access: OA (AMS) · direction: background

Total atmospheric mass 5.1480 × 10¹⁸ kg; dry-air mass 5.1352 × 10¹⁸ kg, from six years of ECMWF and NCEP surface-pressure reanalyses. Used here as the mass term.

VERIFIED 2026-08-30. The AMS full-text page at journals.ametsoc.org/view/journals/clim/18/6/jcli-3299.1.xml was fetched with curl and the tags stripped locally. Abstract, verbatim: "The total mean mass of the atmosphere is 5.1480 × 10 18 kg with an annual range due to water vapor of 1.2 or 1.5 × 10 15 kg... The mean mass of water vapor is estimated as 1.27 × 10 16 kg and the dry air mass as 5.1352 ± 0.0003 × 10 18 kg." The page range 864–875 is confirmed on the same page. No WebFetch was used. This entry previously carried a NOT-OBTAINED flag; it is now cleared.

US Committee on Extension to the Standard Atmosphere 1976 — U.S. Standard Atmosphere, 1976

NOAA-S/T 76-1562. NOAA, NASA and the US Air Force, October 1976. Table 3, p. 3. topic: inventory · camp: mainstream · type: data · access: government · direction: background

The argon mole fraction of dry air, 0.00934, and the mean molar mass of dry air, 28.9644 g/mol. Both are load-bearing in the inventory calculation, so both were verified from the document rather than from memory.

VERIFIED 2026-08-30, and it took work. Both the NOAA scan (ngdc.noaa.gov/stp/space-weather/online-publications/miscellaneous/us-standard-atmosphere-1976/us-standard-atmosphere_st76-1562_noaa.pdf) and the NTRS scan (ntrs.nasa.gov/api/citations/19770009539/downloads/19770009539.pdf) carry an unusable embedded text layer — pdftotext returns pure noise and zero hits for "argon", "0.00934" or "28.9644". They are different files by checksum and both are equally bad. The route that worked: pdftoppm -r 600 on PDF page 19 followed by tesseract --psm 6. That page's running head is "DEFINING CONSTANTS AND EQUATIONS | 3", so PDF page 19 = printed page 3, and it carries "TABLE 3.—Molecular weights and assumed fractional-volume composition of sea-level dry air" with the row "Ar  39.948  .00934".

The mean molar mass is not in Table 2 or 3 and does not need to be. Summing molecular weight times fractional volume down all ten rows of Table 3 gives 28.96443 g/mol, which reproduces the standard 28.9644 to five figures. So the table verifies both constants and checks itself.

Commission on Isotopic Abundances and Atomic Weights (IUPAC) — "Atomic Weight of Argon"

ciaaw.org/argon.htm, retrieved 2026-08-30. topic: isotopes · camp: mainstream · type: compilation · access: OA · direction: background

In 2007, the Commission recommended value for the isotope-amount ratio of n(⁴⁰Ar)/n(³⁶Ar) in air, which is of importance in geochronology and geochemistry, as 298.56(31).

That is the Lee et al. 2006 value, adopted by IUPAC. Also gives the ⁴⁰Ar atomic mass as 39.96238312(2) Da and the terrestrial ⁴⁰Ar amount-fraction range as [0.936, 1.000] — the upper bound being almost pure radiogenic argon in some minerals. Used here as the verified stand-in for Lee et al. 2006, which could not be obtained (below).

Lee, Marti, Severinghaus, Kawamura, Yoo, Lee & Kim 2006 — "A redetermination of the isotopic abundances of atmospheric Ar"

Geochimica et Cosmochimica Acta 70:4507–4512. doi:10.1016/j.gca.2006.06.1563. topic: isotopes · camp: mainstream · type: measurement · access: paywalled · direction: background

The measurement behind ⁴⁰Ar/³⁶Ar = 298.56 ± 0.31 and ³⁸Ar/³⁶Ar = 0.1885 ± 0.0003, which replaced Nier's 1950 value of 295.5 and shifted every atmospheric-argon correction in argon geochronology by about 1%. NOT OBTAINED in full text — routes tried are listed in research/_brief.md. The numerical values used in this work are taken from IUPAC/CIAAW above, which is an independent adoption of them, not a paraphrase.

2. Why the argon must be radiogenic

Meshik, Hohenberg, Pravdivtseva & Burnett 2014 — "Heavy noble gases in solar wind delivered by Genesis mission"

Geochimica et Cosmochimica Acta 127:326–347. doi:10.1016/j.gca.2013.11.030. topic: solar-baseline · camp: mainstream · type: measurement · access: OA (NASA author manuscript, PMC5688518) · direction: undercuts

Measured: solar-wind noble gases in the Genesis mission collectors, by UV-laser ablation and multi-collector mass spectrometry. ³⁶Ar/³⁸Ar = 5.5005 ± 0.0040 to permil precision.

The number this article needs is the ⁴⁰Ar/³⁶Ar baseline, and the paper states it at manuscript p. 7:

we know that the ⁴⁰Ar/³⁶Ar in the SW is small (an upper limit of 4.6 × 10⁻⁴ has been suggested from analyses of urelites by Göbel et al., 1978), suggesting that all of the ⁴⁰Ar is from terrestrial contamination

Locator caution. The PDF obtainable is the NASA author manuscript, whose pagination is NOT the journal's 326–347. Cite the quotation as manuscript p. 7 and say so, or find the published version before printing a journal page number.

The Genesis team's own confirmation of how small the solar ratio is: their cleanest step gave a measured ⁴⁰Ar/³⁶Ar of 1.12 ± 0.01, "among the lowest of all Genesis Ar measurements made so far," and they treat even that as terrestrial contamination.

Göbel, Ott & Begemann 1978 — noble gases in ureilites

The original source of the 4.6 × 10⁻⁴ upper limit. NOT OBTAINED; used only as quoted by Meshik et al. 2014, and the article should say so rather than citing it as if read.

3. How much potassium the Earth has

This is the loose joint. Three published estimates spanning 150–280 ppm are in live use, and the spread is not analytical noise — it is a genuine disagreement about mantle structure.

McDonough & Sun 1995 — "The composition of the Earth"

Chemical Geology 120(3–4):223–253. doi:10.1016/0009-2541(94)00140-4. topic: bulk-earth-K · camp: mainstream · type: model · access: paywalled · direction: background

The canonical bulk-silicate-Earth model; K = 240 ppm. NOT OBTAINED in full text. The 240 ppm figure used here is taken verbatim from Bender et al. 2008 p. 8232, which names it as "the canonical value of 240 ppm for the K content of the bulk silicate Earth" and cites McDonough & Sun for it. That is a secondary route and the article must say so until the primary is read.

Allègre, Hofmann & O'Nions 1996 — "The argon constraints on mantle structure"

Geophysical Research Letters 23:3555–3557. doi:10.1029/96GL03373. topic: bulk-earth-K, degassing · camp: mainstream · type: model · access: paywalled · direction: mixed

The paper that made the argon budget an argument about mantle layering. Whole-Earth K ≈ 250 ppm from U = 20 ppb and K/U = 12,700; upper-mantle K ≈ 50 ppm; therefore a layered mantle with a degassed top and an undegassed bottom. NOT OBTAINED in full text; the parameters above are as reported by Ozima & Podosek 2002 p. 215, which is a secondary route.

direction: mixed because this paper is the clearest mainstream admission that the argon budget does not close cleanly on its own terms. It needs an undegassed lower mantle that later seismology makes hard to defend — a point Bender et al. 2008 p. 8232 makes explicitly.

Arevalo, McDonough & Luhr 2009 — "The K/U ratio of the silicate Earth"

Earth and Planetary Science Letters 278:361–369. topic: bulk-earth-K · camp: mainstream · type: compilation · access: paywalled · direction: background

K/U ≈ 13,800 from a large MORB compilation, giving BSE K ≈ 280 ppm. NOT OBTAINED; used only as a bracket on the sensitivity range.

Murthy, van Westrenen & Fei 2003 — "Experimental evidence that potassium is a substantial radioactive heat source in planetary cores"

Nature 423:163–165. topic: bulk-earth-K · camp: mainstream · type: measurement · access: paywalled · direction: background

Sulphur-bearing metal–silicate partitioning experiments showing K can enter the core; permits up to a few hundred ppm K there. NOT OBTAINED; cited from Huang et al. 2013's reference list, which is on disk. Relevant because core potassium is unavailable for degassing, which lowers the mainstream degassing efficiency — and does nothing whatever for a young earth.

Huang, Chubakov, Mantovani, Rudnick & McDonough 2013 — "A reference Earth model for the heat-producing elements and associated geoneutrino flux"

Geochemistry, Geophysics, Geosystems 14:2003–2029. arXiv:1301.0365. topic: bulk-earth-K · camp: mainstream · type: model · access: OA (arXiv) · direction: background

Already in the source library. Adopts McDonough & Sun 1995 for the BSE, and states the live spread plainly: "Compositional models for the BSE vary by nearly a factor of three in their U content," with K/U ≈ 14,000 (Arevalo et al. 2009). Useful mainly as an on-disk, open-access confirmation that the potassium term is genuinely uncertain.

4. Nuclear data

IAEA Nuclear Data Section — ENSDF decay data for ⁴⁰K

nds.iaea.org/relnsd/v1/data, ENSDF cut-off 30 September 2015, evaluator Jun Chen. Retrieved 2026-08-30. topic: nuclear-data · camp: mainstream · type: data · access: government · direction: background

Half-life 1.248 × 10⁹ yr; ⁴⁰K = 0.0117 atom fraction of natural K; branches β⁻ 89.28 ± 0.11% to ⁴⁰Ca and EC+β⁺ 10.72 ± 0.11% to ⁴⁰Ar; Q(β⁻) = 1310.9051 keV; Q(EC) = 1504.403 keV; mean beta energy 560.18 keV; mean antineutrino energy 727.47 keV; the ⁴⁰Ar 1460.82 keV gamma at 10.66% per decay.

These are the numbers that expose an error in the framing of this task, and they are worth stating loudly. Only 10.72% of ⁴⁰K decays make argon. Making one atom of ⁴⁰Ar therefore costs 9.33 decays, not one. The energy cost per argon atom is 12.4 MeV of nuclear Q, of which 6.1 MeV is deposited as heat and the rest leaves as neutrinos — not the ~1.5 MeV that the electron-capture branch Q alone suggests.

Snelling 2016 — "Determination of the Radioisotope Decay Constants and Half-lives: Potassium-40 (⁴⁰K)"

Answers Research Journal 9:171–196. topic: nuclear-data, rate-argument · camp: creationist · type: review · access: free-publisher · direction: background

The most thorough treatment of ⁴⁰K in the creationist literature — roughly 25,000 words on the measurement history of the decay constants, the branching ratio, and the isotopic abundance of ⁴⁰K. Fair and largely accurate on the nuclear physics.

It is also the cleanest evidence for this article's most important negative finding. Snelling recounts von Weizsäcker's 1937 reasoning in his own words:

The possible modes of decay open to ⁴⁰K were first discussed by Von Weizsäcker (1937), who concluded that ⁴⁰K undergoes branched decay to ⁴⁰Ca and to ⁴⁰Ar, based partly on the fact that the abundance of Ar in the earth's atmosphere is about 1000 times greater than expected when compared to the cosmic abundances of the other noble gases.

That sentence is the atmospheric-argon argument, in its 1937 form, in a creationist journal. Snelling states it and then never returns to it. Searching the full text for "budget", "inventory", and "degassing" returns nothing else. The excess argon anomaly that founded K-Ar dating is reported as history and never treated as a constraint on a young earth — and Slusher's 1981 attempt to treat it as one (§5) is not cited either.

5. The creationist argon literature

Almost everything published by young-earth authors on argon falls into two buckets — excess argon in individual rocks, and argon diffusion at Fenton Hill — and neither is about the atmosphere. Three entries are exceptions: Cook 1966, which is where the argument starts; Slusher 1973/1981, which miscopies Cook; and Vardiman 1985/2005, which addresses the inventory and reaches the opposite conclusion from Slusher without citing him.

Cook 1966 — Prehistory and Earth Models

Melvin A. Cook. London: Max Parrish and Co. Ltd. archive.org identifier prehistoryearthm0000melv. topic: inventory, rate-argument · camp: creationist · type: book · access: printdisabled-searchinside · direction: mixed

The true origin of the young-earth argon argument, and it does not say what the movement has spent fifty years saying it says. Cook was a University of Utah metallurgist and explosives chemist, a Guggenheim Fellow, and the author of the young-earth atmospheric-helium argument as well. Pages 65–68 are his critique of K-Ar dating.

His argon budget, p. 66, verbatim:

Allowing an age of 4.5·10⁹ years for the earth the K⁴⁰ at the beginning would have been about ten times higher than at present or about 2·10²⁰ g. Hence, 1.8·10²⁰ g of K⁴⁰ would have decayed to yield about 1.5·10¹⁹ g of A⁴⁰ (branching ratio 0.085) and 1.6·10²⁰ g of Ca⁴⁰. There are at present 6.6·10¹⁹ g A⁴⁰ in the atmosphere and hydrosphere.

That is a deficit of 4.4, not an excess. Correct his two soft inputs — present bulk-Earth ⁴⁰K of 2 × 10¹⁹ g against 1.16 × 10²⁰ g at 240 ppm, and a branching ratio of 0.085 against the measured 0.1072 — and his ratio falls to about 0.6, next door to the 0.47 computed independently in the article. Cook got the sign and nearly the size right in 1966.

His p. 67 sentence, the one Slusher's note 22 cites:

The earth would have to be about 10¹⁰ years old and the initial K⁴⁰ content of the earth about 100 times greater than at present (about 300 ppm) to have generated the A⁴⁰ in the atmosphere.

That is a statement about potassium, not about argon. Slusher converted it into "there is 100 times more argon than decay can make," which does not follow.

Cook also asserts, on the same page, an extraterrestrial argon influx that Slusher's paragraph flatly denies: "micrometeorites are probably adding above 10⁹ g of argon to the earth's atmosphere each year. This source of argon is at present an order of magnitude greater than the radiogenic argon." The Genesis solar-wind data (§2 above) kill that too, since extraterrestrial argon is nearly pure ³⁶Ar and ³⁸Ar.

Locator. printdisabled, read through bin/iapdsearch.py. prehistoryearthm0000melv_scandata.xml gives an explicit <pageNumber> for 370 leaves — a recorded map, not a guessed offset — with leaf 21 = p. 1 and leaf 390 = p. 358, a constant offset of 20. Leaf 86 = p. 66, leaf 87 = p. 67. Standing caution: the OCR destroys every superscript on this item. All exponents above are reconstructions; the three internal checks that force them are set out in the article's [^cook-1966] footnote. Do not print any exponent from this item without them.

Morris 1974 — Scientific Creationism

Henry M. Morris (ed.). San Diego: Creation-Life Publishers. archive.org identifier scientificcreati0000unse_m7d6. topic: inventory, rate-argument · camp: creationist · type: popular · access: printdisabled-searchinside · direction: undercuts (its own position)

The route by which the miscopied claim reached a mass audience, p. 150:

Most of the argon must have been present there, or in the crust, from the beginning, since there is far too much to have been produced even in five billion years by potassium decay, assuming Cook's calculations are right.

Two things. It independently corroborates the reference chain — Morris names Cook as the source, exactly as Slusher's notes 21 and 22 do. And the hedge, "assuming Cook's calculations are right," is the movement's most-read book declining to vouch for the number it is printing. The claim entered popular circulation flagged as unchecked in 1974 and was never checked.

Locator. printdisabled. _scandata.xml gives leaf 13 = p. 1 and leaf 235 = p. 223, offset 12; leaf 162 = p. 150.

Slusher 1973 and 1981 — Critique of Radiometric Dating, 1st and 2nd editions

ICR Technical Monograph No. 2, Institute for Creation Research, San Diego. archive.org identifiers critiqueofradiom0000slus (1973) and critiqueofradiom0000slus_j1h1 (1981). topic: inventory, rate-argument · camp: creationist · type: book · access: printdisabled-searchinside · direction: undercuts (its own position)

The mis-transmission. 1973 p. 30, 1981 p. 39, item 2, word for word identical in both editions:

There is far too much Ar⁴⁰ in the earth for more than a small fraction of it to have been formed by radioactive decay of K⁴⁰. This is true even if the earth were really 4.5 billion years old. In the atmosphere of the earth, Ar⁴⁰ constitutes 99.6% of the total argon. This is around 100 times the amount that would be generated by radioactive decay over the hypothetical 4.5 billion years. Certainly this is not produced by an influx from outer space. Thus, it would seem that a large amount of Ar⁴⁰ was present in the beginning. Since geochronologists assume that errors due to presence of initial Ar⁴⁰ are small, their results are highly questionable.

The claim is false, and false in the direction that hurts the young-earth position. The air holds about 0.47 times, not 100 times, the ⁴⁰Ar that 4.5 Gyr of ⁴⁰K decay in the bulk silicate Earth produces — an error of roughly 200-fold. Slusher's proposed escape, that most of the argon was primordial, was closed by direct measurement of the solar wind by the Genesis mission twenty-three years later (§2 above).

It is not an incidental slip. Both editions restate it in the Conclusions chapter, in a wider form — 1973 p. 41, 1981 p. 53: "In the potassium-argon method, it is assumed that the initial Ar content of the rock is not important, though its abundance in the lithosphere and atmosphere is about 100 times the amount that would be generated by radioactive decay over 4.5 billion years." Note the widening from "in the atmosphere of the earth" to "in the lithosphere and atmosphere."

Its source. The 1973 reference list, p. 44 (leaf 103), reads "21. Cook, Melvin A. (1966). Op. cit., p. 66." and "22. Ibid., p. 67." The 1981 edition carries the same chain on p. 58 (leaf 66). See the Cook entry above for what those two pages actually say.

Locator. printdisabled; read through bin/iapdsearch.py. 1981: _scandata.xml carries an explicit <pageNumber> for every leaf, leaf 9 = p. 1 through leaf 67 = p. 59, offset 8; leaf 47 = p. 39. Cross-checked against the monograph's own table of contents (leaf 7: "C. Criticism of the Potassium-Argon-Method .... 38") and against Dalrymple's independent 1984 citation. 1973: no page numbers in scandata.xml and only odd leaves carry text; anchored twice, far apart — leaf 15 opens chapter I at p. 1, and the cross-reference on leaf 71 ("See addendum on page 47") matches the ADDENDUM heading on leaf 107. Both give printed = (leaf − 13)/2, so leaf 73 = p. 30, leaf 95 = p. 41 ("IV. CONCLUSIONS"), leaf 103 = p. 44 ("REFERENCES"). The superscript marker on the "100 times" sentence is not directly readable — the endpoint strips it, and the 1973 OCR renders it as a caret plus one digit. The attribution to note 22 is fixed instead by the preceding sentence on the same page, which cites Cook on branching-ratio values that appear verbatim on Cook's p. 66 (note 21's target), making note 22 the next marker and Cook p. 67 its target.

Dalrymple 1984 — "How Old is the Earth: Radiometric Dating"

TalkOrigins Archive edition of Dalrymple's reply to "scientific" creationism, Proceedings of the 63rd Annual Meeting, Pacific Division, AAAS. topic: inventory · camp: counter-apologetics · type: review · access: OA · direction: undercuts

The only published reply to Slusher on this point. Verbatim:

First, there is not more ⁴⁰Ar in the atmosphere than can be accounted for by radioactive decay of ⁴⁰K over 4.5 billion years. An amount of ⁴⁰Ar equivalent to all the ⁴⁰Ar now in the atmosphere could be generated in 4.5 billion years if the Earth contained only 85 ppm potassium. ... The ⁴⁰Ar content of the atmosphere is well known and is 6.6 × 10¹⁹ grams. The estimated ⁴⁰Ar content of the crust and mantle combined is about 4 to 19 × 10¹⁹ grams (60). Thus, the Earth and the atmosphere now contain about equal amounts of ⁴⁰Ar, and the total could be generated if the Earth contained only 170 ppm potassium and released half of its ⁴⁰Ar to the atmosphere.

His 6.6 × 10¹⁹ g matches the value computed independently here (6.591 × 10¹⁹ g) to one part in a thousand. Caution: this online edition omits the reference list, so his reference (60) for the crust-and-mantle estimate cannot be identified without the printed proceedings.

The rest of the corpus — all silent on the inventory

Humphreys 2011 — "Argon diffusion data support RATE's 6,000-year helium age of the earth"

Journal of Creation 25(2):74–77. On disk as humphreys-2011. topic: rate-argument · camp: creationist · type: model · access: free-publisher · direction: supports (on its own narrow question)

Reanalyses Harrison, Morgan & Blackwell 1986 (JGR 91(B2):1899–1908), the argon diffusion study on microcline feldspar from the same Fenton Hill GT-2 borehole that supplied RATE's zircons. Humphreys reads the sample-5 age spectrum (4.56 km, 313 °C) as a 25% ⁴⁰Ar loss rather than Harrison's 20%, applies Harrison's own equation t ≈ πf²/4(D/a²), and gets 5,100 (+3,800/−2,100) years — which he presents as an independent confirmation of the 6,000 ± 2,000 year helium age.

His conclusion, p. 77, verbatim:

These data say that the feldspar generated over a billion years' worth of ⁴⁰Ar, and then retained it, during a period of time that began only thousands of years ago.

What it does address: retention. Given the measured diffusivity at 313 °C, the feldspar in that borehole cannot have held its argon for a megayear at present temperatures.

What it does not address, at all: how much argon exists. The argument is entirely about the ratio of argon lost to argon retained in one mineral separate from one borehole. It never asks where the roughly 6.6 × 10¹⁹ g of ⁴⁰Ar in the air came from, and the words "atmosphere" and "inventory" do not appear in that sense anywhere in the paper. Note also that Humphreys' own framing requires the accelerated decay: "over one billion years' worth of ⁴⁰K to ⁴⁰Ar decay occurred in situ" (p. 76). He needs the argon to have been made fast, which is exactly the premise the atmospheric budget has to price.

Vardiman 2011 — "Both Argon and Helium Diffusion Rates Indicate a Young Earth"

Acts & Facts 40(8):12–13, ICR. On disk as vardiman-2011. topic: rate-argument · camp: creationist · type: popular · access: free-publisher · direction: supports (on the same narrow question)

A popular-level restatement of Humphreys 2011 with no new analysis. Adds one claim Humphreys does not make — that Harrison et al. "rejected several of the samples from their full analysis because the diffusion rates resulted in a young earth." Harrison et al. reported all five samples and stated their own peak-heating durations of 3 to 60 ka; that is not rejection, and Humphreys himself works from their published numbers. Same silence on the atmospheric inventory.

Snelling 2000 — "Geochemical Processes in the Mantle and Crust", RATE Vol. I ch. 5

Vardiman, Snelling & Chaffin (eds), Radioisotopes and the Age of the Earth: A Young-Earth Creationist Research Initiative, ICR/CRS 2000, ISBN 0-932766-62-5. Chapter begins p. 123. Full text on disk. topic: rate-argument, degassing · camp: creationist · type: review · access: book · direction: undercuts (its own position)

CORRECTION 2026-08-30. An earlier draft of this file attributed the creationist excess-argon review to a RATE Vol. I chapter titled "Potassium-Argon and Argon-Argon Dating of Crustal Rocks and the Problem of Excess Argon". No chapter of that title exists in either RATE volume. The real chapter is Snelling's ch. 5 of Vol. I, "Geochemical Processes in the Mantle and Crust", whose §2.1–2.10 are the excess-argon review. Page numbers in it are fixed from running heads at the top of each page: "Geochemical Processes in the Mantle and Crust  n" on odd pages, "n  A. A. Snelling" on even ones.

This chapter turns out to be the most useful creationist source in the file, for a reason its author did not intend. Twice it quotes a measured crustal ⁴⁰Ar degassing flux and never multiplies it out.

p. 149, verbatim:

Drescher et al. [1998] thus estimated a loss rate or degassing flux of 1-6 x 10⁹ atoms m⁻²s⁻¹ for ⁴⁰Ar from crustal rocks, in good agreement with theoretical estimates from accumulated gases in crustal fluids.

p. 159, in Snelling's own voice:

Nevertheless, there is a steady loss of ⁴⁰Ar from crustal rocks to the atmosphere, on the order of 1-6 x 10⁹ atoms m⁻²s⁻¹ [Drescher et al., 1998], which is a result of degassing of primordial ⁴⁰Ar and ⁴⁰Ar from radioactive decay of ⁴⁰K in the mantle and crust.

Multiplied over Earth's surface that is 2.7 × 10⁷ to 1.6 × 10⁸ mol/yr, which brackets Bender et al. 2008's independently measured 1.1 × 10⁸ mol/yr, and gives a 6,000-year shortfall of 1.7 × 10⁶ to 3.5 × 10⁷. Worked in research/argon-budget.ts Part 3c and used in the article.

Silence on the inventory confirmed. §2.4 is titled "Negative 'Ages' and Atmospheric Argon (Ar)" and looks promising, but it is entirely about Dalrymple 1969's negative K-Ar ages and excess ³⁶Ar in individual lavas. Nowhere does the chapter ask how much ⁴⁰Ar the atmosphere contains or where it came from.

Snelling — the rest of the excess-argon corpus

Snelling 1998 (Ngauruhoe, ICC), Austin 1996 (Mount St Helens), Austin & Snelling 1998 (Cardenas Basalt), Snelling 1999 (ICR Impact). All on disk. topic: rate-argument · camp: creationist · direction: background

These are covered by html/unpublished-ai/radiometric-concordance/ and are not this article's subject. They are listed here only to establish the negative: every one of them argues that individual rocks contain argon they should not, and not one of them asks about the global inventory. Considered and not separately cited in the article — they are named as a group in the article's silence table and cross-referenced to radiometric-concordance, with no footnote of their own.

Drescher, Kirsten & Schäfer 1998 — the KTB crustal rare-gas inventory

Earth and Planetary Science Letters 154:247–263. The source of the 1–6 × 10⁹ atoms m⁻²s⁻¹ crustal ⁴⁰Ar flux above. topic: degassing · camp: mainstream · type: measurement · access: paywalled · direction: undercuts

NOT OBTAINED. Used only as Snelling 2000 quotes it, and the article says so. Their figure is a modelled loss rate derived from measured borehole-fluid compositions, not a direct instrument reading, and that qualification is printed in the article too.

Cupps 2014 — "The Noble Clock: Radioactive Dating, Part 3"

Acts & Facts, Institute for Creation Research, 28 November 2014. https://www.icr.org/article/noble-clock-radioactive-dating-part topic: rate-argument · camp: creationist · type: popular · access: free-publisher · direction: background

CORRECTION 2026-08-30. An earlier draft of this file dated this article 2019. The page itself is bylined "FRIDAY, NOVEMBER 28, 2014" and is part 3 of a numbered series whose parts 1 and 2 are cited on the page as Acts & Facts 43(10):8–11 and 43(11):10–13. The URL icr.org/article/noble-clock returns a soft 404 — HTTP 200 with an "The article requested is not found" body — so anything grepped from it is worthless; the working URL is the one above.

Grepping the real page: zero occurrences of "budget", "inventory" or "degassing". Its uses of "atmospheric" are about correcting a sample for absorbed air argon and about the assumption that all measurable ³⁶Ar is atmospheric. Silent on the inventory.

There is, in fact, a quiet tension here worth naming. The excess-argon literature's central claim is that ⁴⁰Ar is abundant and mobile in the crust and mantle and gets into everything. That is a claim about a very large amount of ⁴⁰Ar existing. It is the atmospheric argument's premise, offered by the other side.

Humphreys 2005 — RATE Vol. II ch. 2, §13 "Disposing of Excess Heat"

Radioisotopes and the Age of the Earth vol. II, pp. 25–100; heat section pp. 67–74. ICR full-chapter PDF, now on disk. topic: heat, rate-argument · camp: creationist · type: review · access: free-publisher · direction: undercuts (its own position)

Humphreys' own statement of the problem, pp. 67–68, verbatim:

nuclear decay generates heat! I wrote that without long periods of time in which the heat could dissipate by normal mechanisms, or without some new and faster mechanism, crustal rocks would melt many times over if decay rates were accelerated.

And his own honest assessment of where the answer stands, p. 74:

To summarize the heat problem, we have several lines of physical evidence for volume cooling having occurred, and there is at least one promising theoretical approach we can try. When we can devote more time to the problem, we may see good progress on it.

He also concedes, p. 68, that the problem is not RATE's alone: "heat is not merely a problem for accelerated decay, but also for all Creation or Flood models I know of."

The proposed escape is "volume cooling" — cooling the whole volume simultaneously and abnormally fast, faster than conduction, convection or radiation allow — with Snelling & Armitage's polonium-halo timescales and Baumgardner's geothermal work offered as evidence that it happened. No mechanism is derived, and no number is put on it in this chapter.

Vardiman 1985 — "Up, Up and Away! The Helium Escape Problem"

ICR Impact No. 143, May 1985, Institute for Creation Research. topic: inventory · camp: creationist · type: popular · access: Wayback capture · direction: mixed

Vardiman's Table 1, "Composition of the Atmosphere," gives argon a total mass of 6.59 × 10¹⁹ g — the correct figure, matching the 6.591 × 10¹⁹ g computed independently for the article to three digits. He then treats it as an assumption to be doubted rather than a datum to press:

The amount of argon in the atmosphere is assumed to be fully retained in the atmosphere after radioactive decay of potassium, and permits maximum estimates of helium flux to be made. Unfortunately, the assumption of long ages of the earth underlies the estimates of heat flow and the accumulation of argon in the atmosphere as well.

Access. ICR removed the article; read from the Internet Archive capture of 12 February 1998, https://web.archive.org/web/19980212191721/http://www.icr.org/pubs/imp/imp-143.htm. Do not use the 2008 capture, which returns a publications landing page. There is no imp-143.pdf. Impact articles carry no page numbers.

Vardiman 2005 — "Evidence for a Young Earth from the Ocean and Atmosphere"

icr.org, 8 October 2005, written as a book chapter. topic: inventory, rate-argument · camp: creationist · type: popular · access: free-publisher · direction: mixed

The only place in the entire ICR corpus that states a young-earth position on the atmospheric ⁴⁰Ar inventory as such — and it is the opposite of Slusher's, without citing him:

The large amount of argon in the atmosphere argues for a large amount of nuclear decay, but not necessarily a long period of time.

Vardiman names three escapes: an uncertain crust-to-atmosphere escape rate, accelerated decay, and an unknown initial concentration. The first is the objection the article's measurement route answers, and Bender's ice-core measurement post-dates him by three years. He also mis-states the parent nuclide — "It is produced by the decay of uranium in the rocks of the earth" — which is wrong; atmospheric ⁴⁰Ar is the electron-capture branch of ⁴⁰K.

Loechelt 2012, with Humphreys' reply — Journal of Creation 26(2):45–49

Gary H. Loechelt, Letter to the Editor on "Argon diffusion data support RATE's 6,000-year helium age of the earth," with D. Russell Humphreys' reply at 26(2):48–49. topic: rate-argument · camp: old-earth-christian (Loechelt) / creationist (Humphreys) · type: review · access: free-publisher PDF · direction: undercuts Humphreys 2011

A five-page technical rebuttal of the very paper this article discusses, printed by the venue that published it, and the article did not previously know it existed. Loechelt checks Humphreys' three "best uniformitarian" magma-chamber parameters against seismic and mineral-chemistry measurements and finds all of them wrong in the direction that inflates the heating: radius 9–10 km assumed against 7.5–8.5 km measured, burial depth 3 km against 4.7–9 km, thickness 20 km against 12–15 km, magma temperature 1,000 °C against ~800 °C. Corrected, the conductive model peaks near 130 °C where 230 °C is needed.

Humphreys' reply does not engage the table. It opens on Loechelt's worldview and then argues the helium-in-zircon question instead.

Say plainly that Loechelt is an old-earth Christian critic of RATE, not a young-earth author. This is a critic's letter with a reply, not creationist-on-creationist dispute.

OCR caution, mandatory. These Journal of Creation PDFs use a subsetted font whose italic and ligature runs pdftotext returns as a substitution cipher (YROFDQR → volcano). Every quotation that falls in such a run must be re-read off the rendered page (pdftoppm -r 300 plus tesseract) before it is printed. That was done for the "ignored the hydrothermal system" sentence, the "eyeball interpolation" sentence, and Humphreys' reply opening. Page anchoring: PDF pages 1–5 carry printed folios 45–49, anchored at both ends by OCR of the rendered first and last pages; running foot "JOURNAL OF CREATION 26(2) 2012".

Humphreys 2010 — reply to Loechelt, Journal of Creation 24(3):34–39

topic: method · camp: creationist · type: review · access: free-publisher PDF · direction: background

Cited for one sentence only, p. 35: "(3) It points out an error of mine, for which I'm grateful." The exchange is about helium diffusion in zircons, not atmospheric argon — the word "atmosphere" occurs zero times in the file. It earns its place because it establishes that the Journal of Creation does print substantive corrections, which makes the absence of any correction to Slusher a choice about attention rather than a structural impossibility.

The CRSQ "Minisymposium on Variable Constants", 1990 — Brown vs Gentry

Creation Research Society Quarterly volumes 26–27. Eleven numbered parts, editor Don DeYoung. Parts X and XI read for this article: R. H. Brown, "Radiohalo Evidence Regarding Change in Natural Process Rates," CRSQ 27:100–102; Robert V. Gentry, "Critique of 'Radiohalo Evidence Regarding Change in Natural Process Rates'," CRSQ 27:103ff. topic: rate-argument · camp: creationist · type: review · access: free-publisher PDF · direction: mixed

Internal young-earth disagreement about accelerated decay, printed head to head in the movement's own peer-reviewed journal. Brown argues from radiohalo ring sharpness that half-lives across 21 orders of magnitude "have not varied by more than a factor of two." Gentry, the best-known radiohalo researcher in creationism, rejects it on the next page and states the stakes: "if decay rates have remained constant, then creationists need to know it, for such a view firmly establishes the basis of conventional radiometric dating for fossils as well as rocks."

Access. https://crsq.creationresearch.org/id/eprint/<id>/ then the linked PDF. ids: 690 (DeYoung's editorial), 709 (Brown), 710 (Gentry). Two-column PDFs; pdftotext -layout interleaves the columns, so quotations must be reassembled down a column and checked for continuity. Nine of the eleven parts were not read and are listed under §5b.

Snelling 2016, ARJ 9:173 — the anomaly stated and passed by

See §4 for the full entry. Recorded here because of what it shows about the silence: Snelling writes, in a 26-page ARJ paper on ⁴⁰K, that "the abundance of Ar in the earth's atmosphere is about 1000 times greater than expected when compared to the cosmic abundances of the other noble gases," and then never asks where that argon came from. The numeral is destroyed by a subsetted font in the journal PDF's text layer; it was recovered by rendering PDF page 3 at 300 dpi and OCR'ing it, which also returns the running head carrying the folio 173.

5b. Sources considered and not used

Every entry above is cited in the article except the following, which are recorded here as considered and deliberately not used:

• Snelling 1998, Austin 1996, Austin & Snelling 1998, Snelling 1999 — the excess-argon-in-individual-rocks corpus. Named as a group in the article's silence table and cross-referenced to radiometric concordance, which is where that argument belongs. No separate footnote.
• Porcelli & Ballentine 2002, "Models for the distribution of terrestrial noble gases and evolution of the atmosphere," Reviews in Mineralogy and Geochemistry 47:411–480. Not attempted, not used. This is the standard noble-gas review and would supply a second independent statement of the degassing efficiency. RiMG volumes are often free from the Mineralogical Society of America after a delay. Worth getting before the next revision.
• Turekian 1959, "The terrestrial economy of helium and argon," GCA 17:37–43. Not attempted, not used. The origin of this whole line of argument, and Turekian was the PNAS editor who handled Bender et al. 2008. Wanted for a proper history section, which the article does not currently have.
• Göbel, Ott & Begemann 1978 and Drescher, Kirsten & Schäfer 1998 are cited in the article, but only as their quoting sources report them, and the article says so in both places. Neither was read.
• Overman, Richard 2013, "The Temporal, Geographical and Geological Ubiquity of Excess Argon with a Young-Earth Analysis," Proceedings of the Seventh ICC. Named in the article's silence table, not otherwise used. It compiles 7,404 K-Ar and Ar-Ar ages from 347 papers and is the largest quantitative young-earth argon study in existence — but it is entirely about argon in rocks and never touches the atmospheric inventory. It is named rather than ignored because leaving the movement's biggest argon study unmentioned is the kind of omission a hostile reader finds.
• Snelling, RATE vol. I ch. 5 §2.4, pp. 132–136, "Negative 'Ages' and Atmospheric Argon". Not used. Snelling builds a real dilemma out of Dalrymple's own two explanations for sub-atmospheric ⁴⁰Ar/³⁶Ar in modern lavas. It is the strongest argon material in RATE and it is a good objection of its type, but it attacks K-Ar dating of rocks, not the atmospheric inventory, so it belongs to radiometric concordance.
• The other nine parts of the CRSQ 1990 "Minisymposium on Variable Constants" — Williams, DeYoung, Chaffin (two), Herrmann, Morton, Byl, De Pierre, Baumgardner. Not read. Only Brown (part X), Gentry (part XI) and DeYoung's editorial were obtained. The remaining nine bear on the accelerated-decay section and should be read before the next revision; ids 691, 692, 697, 698, 703, 704, 705, 708 at crsq.creationresearch.org/id/eprint/<id>/.
• Ankeny, Braile & Olsen 1986; Roberts 1991; Nielson & Hulen 1984; Warshaw 1988 — the four measurement papers behind Loechelt's Table 1. Not obtained. They are reported only as Loechelt's table reports them, and the article says so.

6. Adjacent Berean Archive material — cross-reference, do not duplicate

• agents/memory/radiometric-failure-modes.md — the excess-argon case files, the Dalrymple historic-lava audit, the Ngauruhoe numbers, the ~0.4% decay-constant floor.
• agents/memory/radiometric-method-mechanics.md — how K-Ar and Ar-Ar actually work.
• agents/memory/rate-helium-diffusion.md — RATE's zircon helium argument from the same borehole, its history, and what RATE itself conceded.
• agents/memory/hydroplate-heat.md — the accelerated-decay heat problem worked in full, with Brown's 7.72 × 10³⁰ J and the independently computed 1.95 × 10³⁰ J (continental crust, 4.5 Gyr) and 6.18 × 10³⁰ J (bulk silicate Earth). The ⁴⁰K-only figure computed for this article, 2.05 × 10³⁰ J of heat, sits between them, as it must.
• html/unpublished-ai/radiometric-concordance/ — excess argon in K-Ar dating. Already covered there. Not this article's subject.