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, who wrote it, and which way it cuts.

A catalogue of the literature on in-situ cosmogenic nuclide dating — the method reviews, the production-rate calibrations, the burial-dating papers, the failure modes the practitioners publish about themselves, and the young-earth engagement with all of it.

It is deliberately not a reading list of things that agree with this site.  Sources are tagged by the direction they cut.  A reader who wants only the strongest material against the young-earth argument can filter for undercuts and read those.

How to read an entry

Measurement or model.  The most important distinction here.  A ¹⁰Be concentration in a quartz grain is an observation:  atoms counted in an accelerator mass spectrometer.  A production rate is a fitted parameter — the value that best reproduces measured concentrations at sites whose ages are known some other way.  An exposure age is the quotient of the two, and inherits every assumption in the second.  Conflating them is how bad arguments get made on this subject, in both directions.

What the clock depends on.  Cosmogenic dating is not one clock but two, and they have different weak points.  A surface-exposure age is concentration divided by production rate, t = N/P, so it is directly proportional to 1/P and a changed past cosmic-ray flux moves it in exact proportion.  A ²⁶Al/¹⁰Be burial age is t = -ln(R_measured/R_production) / (λ₂₆ - λ₁₀), in which the production rate does not appear at all — only the production ratio and the two decay constants.  Every entry says which of the two it bears on.

Direction.  Whether the source supports, undercuts, or complicates the young-earth position.  Assigned by what the source shows, not what its author believes.  Several mainstream papers here are tagged supports because they concede real accuracy problems, and the one substantial creationist paper on the subject is tagged mixed because its central manoeuvre is circular but its criticism of production-rate calibration is not.

Field definitions

Method reviews — how the clock is built

Gosse & Phillips 2001

John C. Gosse and Fred M. Phillips, "Terrestrial in situ cosmogenic nuclides: theory and application," Quaternary Science Reviews 20(14) (2001): 1475–1560.  doi:10.1016/S0277-3791(00)00171-2

topic: method · camp: mainstream · type: review · clock: both · direction: background · access: web.archive.org capture of neotectonics.seismo.unr.edu/0_COURSES/Geo730-2024/GossePhillips-2001.pdf — the live host times out; the Wayback copy is the complete 86-page article

The standard 86-page reference for the whole method.  Covers all six working nuclides (³He, ¹⁰Be, ¹⁴C, ²¹Ne, ²⁶Al, ³⁶Cl), the production physics, spatial scaling, sample-collection strategy, and error budget.  This is the source for the geomagnetic corrections that the young-earth argument turns on, and it is unusually candid about them.

Two numbers from it matter most here.  First, §3.5.3.2, on reversals:  a simulation dropping field intensity to 20 % of modern between 790 and 770 ka raises the time-averaged production rate at the worst-case site (20° latitude, 3 km elevation) by "approximately 3 %", and the authors conclude that "even in the worst-case scenario, TCN production rates for long (>10 kyr) exposures are essentially indistinguishable from a constant long-term integrated production rate for the same period" (p. 1512).  Second, the caption to Fig. 9:  "today's magnetic field appears to be almost 1.5 times stronger than the average intensity over the past 1 Myr."  That second fact cuts for higher past production — but by tens of percent, not by the factors of 40 to 220 the young-earth reconstruction requires.

Caution for anyone quoting from the PDF:  pdftotext strips the superscripts, so "³He, ¹⁰Be, ¹⁴C, ²¹Ne, ²⁶Al, ³⁶Cl" comes out as "He, Be, C, Ne, Al, Cl", and the two-column layout interleaves.  Do not trust a numeral read out of the extraction without checking it against the rendered page.

Balco, Stone, Lifton & Dunai 2008 — the CRONUS calculator

Greg Balco, John O. Stone, Nathaniel A. Lifton and Tibor J. Dunai, "A complete and easily accessible means of calculating surface exposure ages or erosion rates from ¹⁰Be and ²⁶Al measurements," Quaternary Geochronology 3(3) (2008): 174–195.  doi:10.1016/j.quageo.2007.12.001

topic: production-rate · camp: mainstream · type: model · clock: exposure · direction: mixed · access: hess.ess.washington.edu/math/docs/al_be_v22/Balco_QG_2008.pdf — free, direct, no login

The paper behind the online calculator nearly every published ¹⁰Be exposure age now runs through.  Its value here is that it reports the same age five ways, under five different scaling schemes, and tabulates how far apart they land.

Table 6 gives the reference ¹⁰Be spallation production rate at sea level and high latitude fitted to a common calibration data set under each scheme, in atoms g⁻¹ yr⁻¹:

Spread between the extremes is 5.39/4.84 = 11 %.  Figures 3 and 4 map where the ages diverge:  the St/De ratio reaches 1.1 and 0.9 — a ±10 % disagreement in age — at high elevation and at ages well beyond the calibration sites, and the divergence grows with both.  The authors are blunt about what this means:  "there is no compelling reason for a user to prefer the results from any particular scaling scheme," and "there is no reason to believe that the results from the different scaling schemes are randomly distributed, so averaging them will not yield a more accurate age estimate" (p. 192).

That is the honest published spread between scaling schemes:  about 10 %.  Not a factor.

Borchers et al. 2016 — the CRONUS-Earth calibration, and its own failure report

Brian Borchers, Shasta Marrero, Greg Balco, Marc Caffee, Brent Goehring, Nathaniel Lifton, Kunihiko Nishiizumi, Fred Phillips, Joerg Schaefer and John Stone, "Geological calibration of spallation production rates in the CRONUS-Earth project," Quaternary Geochronology 31 (2016): 188–198.  doi:10.1016/j.quageo.2015.01.009

topic: calibration · camp: mainstream · type: measurement · clock: exposure · direction: supports · access: www.pure.ed.ac.uk/ws/portalfiles/portal/23222855/Borchers2016OpenAccess.pdf — the research.ed.ac.uk /files/ path 403s behind Cloudflare; the pure.ed.ac.uk portalfiles path it redirects to serves the same accepted manuscript to plain curl

The single most useful mainstream source in this file, because it is a concession.  This is the paper that set the production rates now in use, and its own abstract says:

"In general, the results show that the calibrated production rates fail statistical tests of goodness-of-fit. … The root-mean-square percent differences between the median computed ages for these secondary sites and independent ages range from 7.1 % to 27.1 %, differences that are much larger than the typical uncertainties in the site ages.  The results indicate that there are substantial unresolved difficulties in modeling cosmogenic nuclide production and the calibration of production rates."

By nuclide, the RMSE of computed against independent ages at the validation sites (those held out of the fit) was ¹⁰Be 8.3 %, ²⁶Al 7.1 %, ³⁶Cl 17.7 %, ³He 27.1 %.

This paper is also the source Oard 2021 quotes at p. 189 for the circularity of calibration.  The quotation is verbatim — "The production rate parameter is calibrated by finding the value that best fits measured concentrations from a collection of sites for which independent age measurements are available" — and it sits in the Introduction, accepted-manuscript p. 2, lines 51–53.  Oard has represented this source fairly.  The point he does not make is that the resulting inaccuracy is 7–27 %, not 4,000 %.

Note the version caveat:  only the accepted manuscript was obtainable, which carries continuous line numbers rather than journal pagination.  The published article runs pp. 188–198, and its introduction falls on p. 189, so Oard's locator is almost certainly right, but it was not confirmed against the typeset page.

Phillips et al. 2016 — CRONUScalc

Fred M. Phillips, Marc Argento, Greg Balco, Marc Caffee, John Clem, Tibor Dunai, Robert Finkel, Brent Goehring, John Gosse, Antony Hudson, A. J. Timothy Jull, Meredith Kelly, Mark Kurz, Devendra Lal, Nathaniel Lifton, Shasta Marrero, Kunihiko Nishiizumi, Robert Reedy, Joerg Schaefer, John Stone, Terry Swanson and Marek Zreda, "Cosmogenic nuclide systematics and the CRONUScalc program," Quaternary Geochronology 31 (2016): 160–187.  doi:10.1016/j.quageo.2015.09.005

topic: production-rate · camp: mainstream · type: model · clock: both · direction: background · access: NOT OBTAINED — Semantic Scholar reports a BRONZE open-access manuscript at sciencedirect.com/science/article/am/pii/S1871101415300595, which returns Cloudflare HTML to curl and to cdp-fetch; unpaywall lists no repository copy

The companion paper to Borchers 2016, describing the calculation framework.  Not obtained.  Nothing in the present analysis depends on it;  the numbers it would supply (nuclide-specific systematics) are available in Gosse & Phillips 2001 and Balco 2008.

Considered and not used in the article.  Not obtained, and nothing in the argument turns on it.

The ¹⁰Be half-life revision — a case study in self-correction

Chmeleff et al. 2010

Jérôme Chmeleff, Friedhelm von Blanckenburg, Karsten Kossert and Dieter Jakob, "Determination of the ¹⁰Be half-life by multicollector ICP-MS and liquid scintillation counting," Nuclear Instruments and Methods in Physics Research B 268(2) (2010): 192–199.  doi:10.1016/j.nimb.2009.09.012

topic: half-life · camp: mainstream · type: measurement · clock: burial · direction: mixed · access: gfzpublic.gfz-potsdam.de/pubman/item/item_239521_1/component/file_239520/13883.pdf — free GFZ repository copy of the accepted manuscript, direct curl

Measures the ¹⁰Be half-life as 1.386 ± 0.016 Myr, reports the independent parallel measurement of Korschinek et al. on the same master solution as 1.388 ± 0.018 Myr, and recommends the combined value 1.387 ± 0.012 Myr (abstract).

The honesty case study is in the Introduction, p. 192:

"Yet no consensus exists on a reliable value for the half-life of ¹⁰Be.  Several determinations of this half-life have been done in the past … leaving a discrepancy of 14 % between different estimates and splitting the community of users."

And immediately after, the authors are precise about which results the discrepancy did and did not damage:  "these discrepancies did not compromise exposure ages and erosion rate determinations using in-situ produced ¹⁰Be, as long as the half-life used for production rate determinations and unknown samples are the same," but they did matter for "exposure ages for old samples," for "determining burial ages based on the decay of the ²⁶Al/¹⁰Be ratio," and for marine-sediment growth rates.

Cuts both ways, and both should be said.  A field carried a 14 % disagreement in a fundamental constant for decades — that is a real defect, and a young-earth writer is entitled to point at it.  It was then closed by two independent laboratories agreeing to 0.15 %, and closed in the direction that made every burial age older, against the interest of anyone wanting fast answers.

Korschinek et al. 2010

G. Korschinek, A. Bergmaier, T. Faestermann, U. C. Gerstmann, K. Knie, G. Rugel, A. Wallner, I. Dillmann, G. Dollinger, C. Lierse von Gostomski, K. Kossert, M. Maiti, M. Poutivtsev and A. Remmert, "A new value for the half-life of ¹⁰Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting," Nuclear Instruments and Methods in Physics Research B 268 (2010): 187–191.  doi:10.1016/j.nimb.2009.09.020

topic: half-life · camp: mainstream · type: measurement · clock: burial · direction: background · access: NOT OBTAINED directly — Semantic Scholar and unpaywall both report CLOSED, no repository copy. Its result (1.388 ± 0.018 Myr) is quoted verbatim in the Chmeleff 2010 abstract, which was obtained, and that is the route used here

The companion determination.  A different technique (heavy-ion elastic recoil detection) on the same master solution, landing within 0.15 % of Chmeleff.  The agreement of two independent methods is the reason the value is now trusted.

Used indirectly.  Cited in the article's Chmeleff footnote for its 1.388 ± 0.018 Myr value, quoted through the Chmeleff abstract, with the second-hand route stated.

Burial dating — the production-rate-free clock

Balco & Rovey 2008 — the isochron method and the Missouri tills

Greg Balco and Charles W. Rovey II, "An isochron method for cosmogenic-nuclide dating of buried soils and sediments," American Journal of Science 308 (December 2008): 1083–1114.  doi:10.2475/10.2008.02

topic: burial-dating · camp: mainstream · type: measurement · clock: burial · direction: undercuts · access: already in the source library — sources/papers/balco-2008_isochron-cosmogenic-burial-dating.pdf, key balco-2008

The hardest single result in this whole file for the young-earth position, and the one Oard 2021 cites without engaging.

The method:  ²⁶Al and ¹⁰Be are produced in quartz at a fixed ratio, stated at p. 1089 as "6.75:1" (the older 6.1:1 of Nishiizumi et al. 1989 differs only by AMS standardisation, not by physics).  Bury the quartz deep enough to stop the cosmic-ray flux and the two inventories decay at different rates, so their ratio falls.  The isochron refinement is that if a set of samples from different depths in one paleosol share a burial age but differ in inherited nuclide concentration, their ²⁶Al and ¹⁰Be concentrations lie on a straight line whose slope is R_init · e^(-t_b(λ₂₆-λ₁₀)).  Equation (9), p. 1094:

"The important thing about this relation is that we know the production ratio and the decay constants, so the slope of the line depends only on the burial age t_b.  Thus, we do not need any information about the sample depths, the exposure time, or the inherited nuclide concentrations to determine the burial age of the soil."

Read that against the young-earth argument.  The production rate is not in the equation.  A cosmic-ray flux forty times higher in the past changes the concentrations but not the ratio, so it changes the burial age by exactly zero.

The Missouri result.  Four tills in central Missouri, each dated by the isochron in the paleosol beneath it:

Four ages, in correct stratigraphic order, straddling the Brunhes–Matuyama polarity boundary from the right sides.  The polarity of a till and the ²⁶Al/¹⁰Be ratio in the soil under it share no physical parameter whatever.

The paper also states its own decay constants explicitly (p. 1088–89):  ¹⁰Be λ = 5.10 ± 0.26 × 10⁻⁷ yr⁻¹ (Nishiizumi et al. 2007), ²⁶Al λ = 9.83 ± 0.25 × 10⁻⁷ yr⁻¹ (Nishiizumi 2004), giving half-lives of 1.36 and 0.705 Myr and a useful burial-dating range of "approximately 0.2 to 4 Ma" (p. 1089).  It also notes, honestly, that switching from the Nishiizumi 2002 to the Nishiizumi 2007 ¹⁰Be standardisation makes every burial age "approximately 10 percent older" — including all of the authors' own previous work, which they name.

Balco & Rovey 2010 — the Laurentide chronology built on it

Greg Balco and Charles W. Rovey II, "Absolute chronology for major Pleistocene advances of the Laurentide Ice Sheet," Geology 38(9) (2010): 795–798.  doi:10.1130/G30946.1

topic: burial-dating · camp: mainstream · type: measurement · clock: burial · direction: undercuts · access: already in the source library — sources/papers/balco-2010_absolute-chronology-laurentide.pdf

The follow-up that turns the Missouri isochrons into a regional glacial chronology:  advances near 2.4, 1.3 and 0.75–0.2 Ma.  Relevant here mostly for cross-referencing to agents/memory/ice-age.md, where the same paper's statement that "paleosols are nearly always present between tills" is already logged against Oard's contrary claim.

Used.  Cited in the article's Balco & Rovey footnote as the follow-up chronology.

Rovey & Balco 2011

Charles W. Rovey II and Greg Balco, "Summary of Early and Middle Pleistocene glaciations in northern Missouri, USA," Developments in Quaternary Science 15 (2011): 553–561.  doi:10.1016/B978-0-444-53447-7.00043-X

topic: burial-dating · camp: mainstream · type: compilation · clock: burial · direction: undercuts · access: already in the source library

The stratigraphic write-up of the same section.  Background.

Considered and not used in the article.  It adds stratigraphic description to a result the article takes from Balco & Rovey 2008 directly;  nothing in the argument needed it.

Granger's burial-dating reviews

Darryl E. Granger, "A review of burial dating methods using ²⁶Al and ¹⁰Be," in In Situ-Produced Cosmogenic Nuclides and Quantification of Geological Processes, GSA Special Paper 415 (2006): 1–16; and Granger, "Cosmogenic Nuclide Burial Dating in Archaeology and Paleoanthropology," Treatise on Geochemistry (2nd ed., 2014), ch. 14.4.

topic: burial-dating · camp: mainstream · type: review · clock: burial · direction: undercuts · access: NOT OBTAINED — GSA Special Paper 415 ch. 1 is paywalled at pubs.geoscienceworld.org; the Treatise chapter is paywalled at ScienceDirect; unpaywall reports no OA location for either. ResearchGate holds request-only entries. Not retried on hoopla or archive.org

Cited here only for completeness.  Balco & Rovey 2008 restates the underlying equations in full, so nothing in the present analysis is blocked by not having Granger.  If a later agent wants Granger's compilation of published burial ages, archive.org search-inside on the GSA volume is the untried route.

Considered and not used in the article.  Not obtained;  Balco & Rovey 2008 restates the burial-dating equations in full, so the article cites that instead.

Independent tests and known-age calibration

The calibration sites themselves

The production rates in Balco 2008 and Borchers 2016 were set at sites whose ages were established by something other than cosmogenic nuclides.  This should be stated plainly rather than buried, because it is a real limit on what the method can be used to prove:

• Promontory Point, Lake Bonneville, Utah (PPT) — the Bonneville shoreline, dated by ¹⁴C on associated material to ~18.3 ka. Oard 2021 p. 37 reports the resulting fitted ¹⁰Be production rate as 15.1 atoms g⁻¹ yr⁻¹ at a measured concentration of 2.75 × 10⁵ atoms g⁻¹.
• Scottish Highlands moraine (SCOT) — a moraine with ¹⁴C on associated organic matter at 12,480 BP; measured ¹⁰Be 6.93 × 10⁴ atoms g⁻¹, fitted production rate 5.50 atoms g⁻¹ yr⁻¹ at 320 m, 3.95 at sea level.
• New Zealand (NZ) and Peru (PERU) — the other two ¹⁰Be primary sites in Borchers 2016.
• Sierra Nevada glacial pavements — Nishiizumi et al. 1989's original calibration, and Lal 1991's, at ~11 ka deglaciation.

The circularity is bounded, not total, and the boundary is worth stating precisely.  The production rate is fitted to a handful of independently dated sites and then predicts concentrations at sites held out of the fit.  Borchers 2016 ran exactly that test and reported the misfit:  8.3 % for ¹⁰Be across ten secondary sites, 7.1 % for ²⁶Al across five, 17.7 % for ³⁶Cl across twenty, 27.1 % for ³He across thirteen.  A method that were purely circular could not fail such a test, and could not fail it by different amounts for different nuclides.

Kurz et al. 1990 — cosmogenic ³He on radiocarbon-dated Hawaiian lava flows

Mark D. Kurz, D. Colodner, T. W. Trull, Richard B. Moore and K. O'Brien, "Cosmic ray exposure dating with in situ produced cosmogenic ³He:  results from young Hawaiian lava flows," Earth and Planetary Science Letters 97 (1990): 177–189.  doi:10.1016/0012-821X(90)90107-9

topic: calibration · camp: mainstream · type: measurement · clock: exposure · direction: mixed · access: abstract only, fetched in full from two independent routes that agree — the USGS Publications Warehouse record at pubs.usgs.gov/publication/70016183 (Moore was a USGS author) and a transcription at www.physics.purdue.edu/primelab/research/papers/ku90g.html. The body of the paper is paywalled at Elsevier and was not read

The classic zero-inheritance test:  lava flows have no prior exposure by construction, and these were dated by radiocarbon on associated material.  Flows from Hualalai and Mauna Loa "ranging in age from 600 to 13,000 years," chosen specifically for the absence of erosion or soil cover.

Genuinely double-edged, and the article reports both edges.  The inferred sea-level ³He production rate "was found to vary significantly, ranging from 47 to 150 atoms g⁻¹ yr⁻¹."  Binned:  125 ± 30 over the past 2,000 years, 55 ± 15 between 2,000 and 7,000, and 127 ± 19 between 7,000 and 10,000.  Total swing "a factor of 2.3 ± 0.8," which the authors immediately call "poorly determined due to the large uncertainties in the youngest samples and questions of surface preservation for the older samples."  Theory predicts less for the same dipole variation:  "a factor of 1.15–1.65."

That is a bigger Holocene production-rate wobble than the 3 % that reversal modelling gives for long exposures, and a young-earth writer is entitled to it.  It is also non-monotonic — the minimum is in the middle of the record, not at the old end — which is not the shape a flux decaying through the Ice Age would leave.  And the operational conclusion cuts the other way:  "the data demonstrate that it is feasible to date samples as young as 600 years of age providing that there has been no erosion or soil cover."

Licciardi et al. 1999 — the recalibration that tightened it

J. M. Licciardi, M. D. Kurz, P. U. Clark and E. J. Brook, "Calibration of cosmogenic ³He production rates from Holocene lava flows in Oregon, USA, and effects of the Earth's magnetic field," Earth and Planetary Science Letters 172, nos. 3–4 (1999): 261–271.

topic: calibration · camp: mainstream · type: measurement · clock: exposure · direction: undercuts · access: NOT OBTAINED directly; its headline result is quoted in Gosse & Phillips 2001 p. 1516, which was obtained, and that is the route used

Recalibrated the independent lava ages and renormalised all published ³He rates, their own included.  As Gosse and Phillips report it:  "The average normalized production rate reported by Licciardi et al. is 119 ± 1 atoms g⁻¹ yr⁻¹ based on 44 measurements that span from about 600–17,500 yr.  The precision and consistency of these measurements make the ³He system the best calibrated, and also suggests than any dipole or non-dipole field effects were not significant."

Forty-four independently dated flows spanning 600 to 17,500 years, fitted by one production rate to about 1 %.  This is the strongest single piece of known-age validation in the file, and it is why the Kurz scatter has to be reported alongside it rather than instead of it — Gosse and Phillips say in the next sentence that the low-latitude Kurz rates "have a large range (55 ± 9–231 ± 101 atoms g⁻¹ yr⁻¹) over the Holocene and are higher, it is possible that there was a magnetic (dipole or non-dipole) or surface effect on these data."

Ashik Kol volcano — a production clock against a decay clock

topic: calibration · camp: mainstream · type: measurement · clock: exposure · direction: undercuts · access: Gosse & Phillips 2001 p. 1550, obtained

"The uncertainty-weighted mean of 21 ³⁶Cl age determinations from the Ashik Kol volcano in the Kun Lun Shan (northern Tibetan Plateau) was 66,000 ± 1000 years.  The result of a ⁴⁰Ar/³⁹Ar age determination on the same basaltic trachyandesite was 62,000 ± 1300 years."

Two clocks with no parameter in common — one counting atoms made by cosmic rays at the surface, one counting atoms made by potassium decaying inside the rock — agree to about 6 % at 66 ka.  Caveat stated in the article as well as here:  Gosse and Phillips attribute the argon-argon age to a 1998 personal communication, so this is a comparison reported in a review, not a published pair of ages.

Zreda et al. 1993 — the Lathrop Wells ³⁶Cl test

Marek G. Zreda, Fred M. Phillips, P. W. Kubik, P. Sharma and D. Elmore, "Cosmogenic ³⁶Cl dating of a young basaltic eruption complex, Lathrop Wells, Nevada," Geology 21 (1993): 57–60.  doi:10.1130/0091-7613(1993)021<0057:CCDOAY>2.3.CO;2

topic: calibration · camp: mainstream · type: measurement · clock: exposure · direction: undercuts · access: NOT OBTAINED. Unpaywall and OpenAlex both report the record closed with no repository copy; the OSTI API, the USGS Publications Warehouse and the publisher were all tried and none served it

The other standard zero-inheritance eruption test.  Not read.  The only thing said about it in the article comes from a source that was read:  Gosse & Phillips 2001 p. 1546 report that at Lathrop Wells, weathered olivines replaced with iddingsite gave ³⁶Cl exposure ages "30% older than unweathered samples from the same surface," which is a caution about sample selection rather than a validation.  The article says plainly that the known-age validation exists in the literature and that only two of its three legs were verified here.

The ¹⁰Be / ¹⁴C / tree-ring synchronisms — the real check on a changed flux

topic: ice-core · camp: mainstream · type: measurement · clock: background · direction: undercuts · access: all four verified previously in this repository and recorded in agents/memory/ice-core-layer-counting.md and decay-free-clocks.md

These are meteoric ¹⁰Be, not in-situ, so they do not date a rock surface.  They matter because they are driven by the same cosmic-ray flux, and because they are cross-dated against tree-ring ¹⁴C to the year.  A flux that swung by two orders of magnitude inside 4,500 years would have to have left them synchronous.

• Miyake et al. 2012, Nature 486:240–242 — "a rapid increase of about 12‰ in the ¹⁴C content from ad 774 to 775, which is about 20 times larger than the change attributed to ordinary solar modulation," in Japanese cedar.
• Sigl et al. 2015, Nature 523:543–549 — the matching ¹⁰Be maxima in NEEM-2011-S1, NGRIP and WDC, "offset by 7 years from the tree-ring event" on the old age models; the corrected chronologies are "accurate to within less than ±5 years during the past 2,500 years."
• Paleari et al. 2022, Nature Communications 13:214 — the 7176 BCE solar particle event in NGRIP, EGRIP, GRIP and EDML ¹⁰Be, matching the tree-ring date to about one year after the standard GICC05 adjustment.
• Bard et al. 2023, Phil. Trans. R. Soc. A 381:20220206 — the 14.3 ka event, GRIP ¹⁰Be at 14,301–14,292 cal BP against tree-ring ¹⁴C at 14,300–14,299, a difference of "only a decade, at the most" against an 85-year 1σ.

This is where the article makes the case against a changed flux, and it says explicitly that the ice-core concentration profiles do not make it.  Oard's own concentration-times-accumulation arithmetic gives 33–130×, which overlaps the 20–222× his in-situ sites demand.  Claiming the ice cores refute him outright would be overstating.

Lifton et al. 2015 — the Bonneville calibration paper

Nathaniel Lifton, Marc Caffee, Robert Finkel, Shasta Marrero, Kunihiko Nishiizumi, Fred M. Phillips, Brian Goehring, John Gosse, John Stone, Joerg Schaefer, Brent Theriault, A. J. T. Jull and Kees Fifield, "In situ cosmogenic nuclide production rate calibration for the CRONUS-Earth project from Lake Bonneville, Utah, shoreline features," Quaternary Geochronology 26 (2015): 56–69.  doi:10.1016/j.quageo.2014.11.002

topic: calibration · camp: mainstream · type: measurement · clock: exposure · direction: mixed · access: NOT OBTAINED — paywalled at ScienceDirect; unpaywall reports no OA copy; no repository version found. Its headline numbers are available second-hand through Oard 2021 pp. 37–38, which is how they are used here, and that dependence is flagged in the brief

The Bonneville shoreline and Tabernacle Hill basalt calibration.  Worth obtaining if this article is written up, because it is the one calibration site where a creationist has published a specific arithmetical objection (Oard's altitude-scaling complaint, below), and answering that objection properly needs the primary.

Schaefer et al. 2016 — the GISP2 bedrock

Joerg M. Schaefer, Robert C. Finkel, Greg Balco, Richard B. Alley, Marc W. Caffee, Jason P. Briner, Nicolás E. Young, Anthony J. Gow and Roseanne Schwartz, "Greenland was nearly ice-free for extended periods during the Pleistocene," Nature 540 (2016): 252–255.  doi:10.1038/nature20146

topic: failure-mode · camp: mainstream · type: measurement · clock: exposure · direction: mixed · access: NOT OBTAINED — nature.com paywall; the registered-reader AAAS/Nature account does not open it. Its numbers are used here only as Oard 2021 pp. 36–37 reports them, and that dependence is flagged

The 1.55 m of granite bedrock under the GISP2 ice core:  ¹⁰Be from 24,800 atoms g⁻¹ at the rock surface down to 9,800 atoms g⁻¹ at 1.55 m, an assumed production rate of 4.1 atoms g⁻¹ yr⁻¹, and a best-fit cumulative exposure of about 280 ka after allowing for ~1.3 m of eroded rock.  Included because it is one of Oard's seven showcase sites and because it is genuinely awkward for the mainstream — climate models say Greenland should have held ice through the whole Quaternary, and the exposure result says it did not.  A young-earth writer should notice that the discomfort here is real but is a discomfort about ice sheets, not about the clock.

Balco et al. 2013 — Unaweep Canyon fill

Greg Balco, Gerilyn S. Soreghan, Dustin E. Sweet, Kristen R. Marra and Paul R. Bierman, "Cosmogenic-nuclide burial ages for Pleistocene sedimentary fill in Unaweep Canyon, Colorado, USA," Quaternary Geochronology 18 (2013): 149–157.  doi:10.1016/j.quageo.2013.02.002

topic: burial-dating · camp: mainstream · type: measurement · clock: burial · direction: undercuts · access: NOT OBTAINED — paywalled at ScienceDirect; no repository copy in unpaywall. Oard 2021 p. 35 reports its concentrations (1.12 × 10⁵ atoms g⁻¹ at 112.7 m to 3.42 × 10⁵ at 243.6 m depth) and its ages (0.71–1.69 Ma)

Oard's first showcase, and the one where his own case is weakest, because the ages here are burial ages, not exposure ages.  His proposed explanation — that the sediment was surface-exposed before the Flood and swept in — has to survive the fact that a burial age reads the ²⁶Al/¹⁰Be ratio, not the concentration, and so is unmoved by any amount of pre-Flood irradiation.  Getting the primary would let a writer check whether these are simple burial ages or isochron ages, which matters.

Considered and not used in the article.  Not obtained.  Unaweep is Oard's one Flood-age showcase, and the article's case rests on the Missouri isochrons instead, where the ages, the stratigraphy and the magnetostratigraphy are all published together.  Whether the Unaweep ages are simple or isochron burial ages is still unknown, and until it is known the site cannot carry weight in either direction.

Failure modes the field publishes about itself

Inheritance, erosion, and moraine-boulder scatter

Two things make an exposure age wrong in a known direction, and both are standard in the literature rather than hidden.

Inheritance — nuclides accumulated during an earlier exposure, before the surface was made — pushes an age too old.  Gosse & Phillips 2001 §5 treats it at length.  Oard 2021 p. 33 states it correctly and cites Balco 2017b for the admission that inheritance in striated surfaces "usually is not known until the measurements turn out different from the 'known' age."

Erosion of the sampled surface pushes an age too young, because atoms are removed with the rock.  This is the important asymmetry, and it is the one a young-earth argument has to reckon with:  when the true exposure age is unknown, an uncorrected cosmogenic exposure age is a minimum.  Oard 2021 p. 36 acknowledges this for the Australian inselbergs — "the figures are minimums because a little erosion would have already taken place" — which means his own showcase numbers are floors, and the flux factors he needs are floors too.

Moraine-boulder scatter from exhumation, toppling and snow cover is the dominant practical error in glacial applications.  Oard reports it at Hickory Run, where ¹⁰Be ranges over a factor of 7.4 across the same boulder field (0.44 to 3.26 × 10⁶ atoms g⁻¹), attributed by the original authors to boulders having moved and flipped.

topic: failure-mode · camp: mainstream · direction: supports — these are genuine, published, and material.  They are also bounded and signed, which is what keeps them from doing the work the young-earth argument needs.

Geomagnetic variation — the honest opening, quantified

topic: geomagnetic · camp: mainstream · direction: supports · source:  Gosse & Phillips 2001 §3.5.3

This is where the young-earth case is genuinely strongest, so it should be stated at full strength.  Production rate depends on the geomagnetic cutoff rigidity, which depends on field strength, which has demonstrably varied.  From Gosse & Phillips:

• Today's field is "almost 1.5 times stronger than the average intensity over the past 1 Myr" (Fig. 9 caption, p. 1512). A weaker past field means a higher past production rate. The correction is in the young-earth direction.
• The effect is strongly latitude-dependent, greatest near 20° geomagnetic latitude and negligible above about 58–60°, where the cutoff rigidity is already zero.
• But the magnitude is small when integrated. A worst-case reversal simulation — field dropped to 20 % of modern for 20 kyr — moves the time-averaged production rate by "approximately 3 %."
• Non-dipole components account for about 20 % of the total field (McElhinny & Senanayake 1982, quoted at p. 1516), and a quadrupole term of "approximately 6.2 ± 4.7 %" of the dipole averaged over 780 kyr (Acton et al. 1996).

Oard 2021 uses exactly these facts, in Table I, and reaches exactly the right conclusion about them:  each is real, and each is small.  His Table I entries read "Effect likely small" for the quadrupole and "the net effect likely was small" for reversals.  He is right, and it is to his credit that he says so.  It also means the geomagnetic route cannot supply the factors he needs, and he does not claim it does.

The young-earth engagement

Oard 1997 — the calibration-circularity argument, twenty-four years early

Michael J. Oard, "New Dating Method Calculates Unreasonably Low Rates of Granite Erosion in Australia," CEN Technical Journal 11(2) (1997): 128–130.

topic: creationist · camp: creationist · type: model · clock: exposure · direction: mixed · access: creation.com/images/pdfs/tj/j11_2/j11_2_128-130.pdf — free, direct curl, 80 KB; page numbers pinned from the printed running heads

The earliest young-earth engagement with in-situ cosmogenic dating found anywhere, and the one carrying the best argument.  Its occasion is Bierman and Turner's ¹⁰Be/²⁶Al erosion rate of about 0.7 m/Myr on granite inselbergs of the Eyre Peninsula, South Australia, which Oard calls unreasonably low.  Most of the piece is an erosion-rate argument belonging to erosion-rates.

What matters here is p. 129.  Oard describes the empirical calibration accurately — a concentration measured by AMS "in a material of 'known' age," divided by that age to give a production rate, then extrapolated by latitude and altitude — names the anchor as Nishiizumi's glacially polished Sierra Nevada quartz whose surface "was estimated to be 11,000 years old based on the C-14 age of organic remains associated with the surfaces," and concludes:

"Because of this calibration, the in situ cosmogenic radioisotope dating method is not independent.  Its accuracy depends upon the accuracy of other dating methods, in this case carbon-14 dating."

direction: mixed because that is correct, and still correct:  all four of Borchers 2016's primary ¹⁰Be sites are radiocarbon-anchored, with varve chronology appearing only at a secondary site.  What bounds it is the hold-out test, the narrow age range of the anchoring radiocarbon, and — decisively — the fact that a burial age contains no production rate to calibrate.

Two further things this entry exists to record.  First, the same page shows the calibration moving:  the "known" age of the Sierra pavements was later raised to about 14,000 years, lowering the fitted rate.  That is a real demonstration of the dependence, made by Oard from the mainstream's own revision.  Second, p. 130 already contains the 2021 paper in embryo — the production rate "could be multiplied by two or three times," even so "we still have too much cosmogenic radioisotope accumulation," and therefore "the only other possibility … is by postulating a significantly higher cosmic ray intensity over the early centuries following the Flood."  The 2021 paper is that programme carried out.  He also judges the geomagnetic route "only of second-order importance," which his 2021 Table I repeats.

Oard 2014 — the field-results argument, and the better half of the 2021 case

Michael J. Oard, "Were the Wind River Terraces Caused by Multiple Glaciations?" Creation Research Society Quarterly 50(3) (Winter 2014): 154–171.

topic: creationist · camp: creationist · type: model · clock: exposure · direction: mixed · access: crsq.creationresearch.org/id/eprint/1149/ — free PDF, direct curl

A citation trap first.  The CRSQ EPrints record calls this "50 (3): 3."  That last number is the article's position in the issue, not its first page.  The real pagination, printed at the head of the PDF's first page, is 50:154–171, and the running heads confirm it.  The same trap applies to Oard 2021, listed as "58 (1): 3" and really 58:30–48.  Pin every CRSQ page from the PDF, never from the repository citation string.

Oard's other cosmogenic argument, and it attacks something different from the 2021 paper.  2021 attacks the production rate.  This one attacks the published ages by pointing at how far they disagree with each other and with tephrochronology on one landform.  Terrace WR7 on the Wind River carries the Lava Creek B ash on bedrock, dated by tephrochronology at 660 kyr;  cosmogenic depth profiles give about 300 kyr (Hancock et al. 1999) and possibly 250 kyr (Phillips et al. 1997);  ²³⁰Th/U on pedogenic carbonate gives 140–315 kyr (Sharp et al. 2003, whose paper is U-series, not cosmogenic — Oard's sentence does not distinguish them).  Because higher terraces are dated by extrapolating the incision rate down from WR7, the highest terrace WR15 comes out at 1.7 Ma on the ash date and 431–511 kyr on the cosmogenic dates (p. 164).

He quotes the practitioners accurately against themselves, at p. 164, from Hancock et al. 1999 p. 57:  "the continuing difficulty of precisely dating depositional surfaces older than a few 100 ka [thousand years] with CRN, because of the uncertainties in the geologic history of the surfaces and the large errors arising from calibrations of the rate of production which are inherent in dating surfaces with CRNs."

direction: mixed.  The discordance is real and larger than the 7–27 % hold-out figure.  It is also a factor of two to four, against the factor of 55 to 150 his own chronology needs on that terrace.  And it does not touch burial dating at all:  the word "burial" does not occur in the paper, and Balco and Rovey are not cited.  The article uses this in §"The honest limits of the method."

Oard 2021 — the most substantial treatment

Michael J. Oard, "Much Greater Cosmic Rays During the Ice Age and Before," Creation Research Society Quarterly 58(1) (2021): 30–48.

topic: creationist · camp: creationist · type: model · clock: exposure · direction: mixed · access: already in the source library — sources/papers/oard-2021f_much-greater-cosmic-rays-ice-age.pdf and .txt, key oard-2021f; also at crsq.creationresearch.org/id/eprint/1275/

The fullest place a young-earth writer has taken cosmogenic nuclide dating seriously, worked through published concentrations, and produced numbers.  It is the third of his four pieces on the subject;  see Oard 1997 and Oard 2014 below.  It deserves to be engaged at that level rather than dismissed, and the substance is set out in research/_brief.md.

In outline:  Oard accepts the measured ¹⁰Be concentrations as real, accepts the present-day production rates as roughly right, and rejects the ages.  He derives a single global correction factor of three from the ratio of the Scottish moraine's secular age (12,480 yr) to the age his flood/ice-age chronology assigns it (4,000 yr), applies it everywhere, and finds that seven showcase sites still need a further factor ranging from about 0.8 to 74.  He reads that residual as a real, declining cosmic-ray flux:  very high during the Flood, dropping through the Ice Age, at modern values by its end.  He proposes a nearby supernova as the cause and links it to accelerated decay.

Four complications he lists himself (Table I, p. 39):  the uniformitarian production rates (his ×3), accelerated radiometric decay ("Unknown but will assume small"), a possible post-Flood quadrupole field ("Effect likely small"), and an oscillating field during rapid reversals ("net effect likely was small").  Three of the four he judges negligible, which leaves the ×3 and the site-by-site residual carrying the entire argument.

Direction is mixed, not undercuts, for two reasons.  His criticism of production-rate calibration is accurate and correctly sourced — he quotes Balco 2017a and Borchers 2016 verbatim and fairly.  His reconstruction of past flux, however, is circular in a way that the arithmetic makes visible;  see the brief.

Crucially:  he cites Balco & Rovey 2008 (p. 33) for burial dating and never returns to it.  His only treatment of the ²⁶Al/¹⁰Be ratio is a single paragraph on p. 39 conceding that measured ratios of "around three or four" imply "hundreds of thousands to a few million years" and attributing that to post-Flood accelerated decay — an appeal that the arithmetic in research/burial-dating.ts prices at a factor of 241 to 373 in the decay constants of two low-Z nuclides, immediately after he has written that accelerated decay "is possible … less for low atomic number nuclides."

Oard 2013 — the a-priori dismissal

Michael J. Oard, "Surficial continental erosion places the Flood/post-Flood boundary in the late Cenozoic," Journal of Creation 27(2) (2013): 62–70.

topic: creationist · camp: creationist · type: model · clock: exposure · direction: undercuts · access: creation.com/images/pdfs/tj/j27_2/j27_2_62-70.pdf — free, direct curl

Included because it shows the position Oard held before he did the arithmetic, and because it is the source cross-referenced in agents/memory/erosion-rates.md.  At p. 62:

"There are several methods for estimating the amount of erosion in a region.  Some of them are indirect, such as chemical and cosmogenic isotopic methods, which rely on radiometric dating.  Since these methods are based on uniformitarian assumptions, other more scientific methods will be used."

Tagged undercuts because it is a bad argument by the standards this site holds itself to.  Cosmogenic exposure dating is not "radiometric dating" in the sense meant — a ¹⁰Be exposure age depends on a production rate, and for ages under ~100 kyr the decay correction is a few percent or less.  Calling a method uniformitarian and setting it aside is not an engagement with it.  Oard 2021 is a substantial improvement on this.

The Sterkfontein items — CMI does engage burial dating

"New dates for South African fossils cause contention," Creation 44(4) (October 2022): 9, unsigned;  and "What date would you like?", Creation 45(2) (April 2023): 10, unsigned.

topic: creationist · camp: creationist · type: popular · clock: burial · direction: mixed · access: creation.com/en/articles/new-dates-for-south-african-fossils-cause-contention and creation.com/en/articles/what-date-would-you-like — both HTTP 200 to a plain curl with a browser user-agent; the Cloudflare interstitial that blocked the first sweep does not appear on article URLs, only on the search endpoint

These falsify the article's original negative finding, and they are the only young-earth engagement with ²⁶Al/¹⁰Be burial dating that exists.  Both report Granger et al. 2022 on Sterkfontein.  The 2022 item names the method — "They used a method known as Cosmogenic Nuclide Burial Dating" — and the 2023 item lays out the discordance:  "Earlier dates on flowstone using both uranium-lead and paleomagnetic methods ranged from 2.1 to 2.6 My.  The new dates, based on measuring aluminum and beryllium isotopes, ranged from 3.41 to 3.67 My.  Earlier electron spin resonance (ESR) dating of the actual fossils ranged from ∼1 to 4 My."

They are news items of two and four paragraphs, not technical papers, and neither disputes the physics.  The argument is method discordance, and the 2023 item's own alternative — "The caves formed late in Noah's Flood some 4,500 years ago" — is a factor of two hundred to eight hundred below the bottom of the range it complains about.  Answered in the article's objections section.

Granger et al. 2022 — the Sterkfontein isochron itself

Darryl E. Granger, Dominic Stratford, Laurent Bruxelles, Ryan J. Gibbon, Ronald J. Clarke and Kathleen Kuman, "Cosmogenic nuclide dating of Australopithecus at Sterkfontein, South Africa," PNAS 119(27) (2022): e2123516119.  doi:10.1073/pnas.2123516119

topic: burial-dating · camp: mainstream · type: measurement · clock: burial · direction: undercuts · access: the PNAS page returns 403 to a plain fetch; the full text is CC BY 4.0 and comes back as JATS XML from Europe PMC at www.ebi.ac.uk/europepmc/webservices/rest/PMC9271183/fullTextXML

The paper behind both CMI items, and the same isochron method as Balco & Rovey 2008.  An isochron burial date of 3.41 ± 0.11 My in the lower middle part of Member 4, simple burial dates of 3.49 ± 0.19 My and 3.61 ± 0.09 My, alongside the 3.67 ± 0.16 My isochron for StW 573 published in Nature in 2015.

Three things in it answer the discordance objection directly.  The abstract states the stratigraphic case:  "We show that these previously dated flowstones are stratigraphically intrusive within Member 4 and that they therefore underestimate the true age of the fossils."  The Discussion refuses to throw the other methods out:  "We believe that previous dating of flowstones by U-Pb and paleomagnetism is correct but that the dates indicate the age of flowstone deposition rather than accumulation of the breccia."  And the isochron carries an internal check nothing was fitted to — the intercept gives a post-burial ¹⁰Be production rate of 0.028 ± 0.003 at g⁻¹ yr⁻¹ against an expected 0.030 at ten metres depth, with a mean square weighted deviation of 1.09.

The Discussion also names two independent validations of the method, neither obtained for this article and both used only as Granger reports them:  Zhao et al., Quaternary Geochronology 34 (2016): 75–80, testing the isochron against ⁴⁰Ar/³⁹Ar in the Pulu volcanic sequence, and Tu et al., Quaternary Geochronology 41 (2017): 174–179, testing it against palaeomagnetism at Lantian.

Wise 1986 — a young-earth scientist setting the standard

Kurt P. Wise, "The Way Geologists Date!", Proceedings of the First International Conference on Creationism (Pittsburgh: Creation Science Fellowship, 1986), Volume 1:I, pp. 135–138.

topic: creationist · camp: creationist · type: review · clock: background · direction: undercuts · access: cedarville.tind.io/record/20758/files/ICC86V1_26_The_Way_Geologists_Date.pdf — free, direct curl with a browser user-agent; CC BY-NC-ND 4.0

Not about cosmogenic dating, and included anyway, because it states the standard this article applies and states it from inside the movement.  Abstract, p. 135:  "Creationists commonly claim each of these techniques is invalid.  Carefully considered, each technique has difficulties, but none of them can be considered faulty enough to be invalid."  On the assumption-attack, p. 137:  "Creationists typically call the remainder of the points invalid assumptions.  In most cases, though, they are not assumptions.  Though they lack complete proof, they do not completely lack proof."  And p. 138:  "a simple list of errors is insufficient to reject the method.  If creationism is true, radiometric dates are wrong, but the fact that they are wrong in the same direction (all too old) must be explained for a critique to be complete."

The scan is a typescript and its OCR capitalises "invalid" and renders "is" as "1s" in places;  those are optical artefacts, corrected here.

Mogk 2023 — the one other young-earth author who has looked

Nathan Mogk, "Tapping the Hourglass: Disequilibrium Relaxation Following Accelerated Nuclear Decay," Proceedings of the Ninth International Conference on Creationism (2023), pp. 327–345.

topic: creationist · camp: creationist · type: model · clock: burial · direction: background · access: cedarville.tind.io/record/21188/files/20_Mogk_1493_Tapping_the_Hourglass.pdf — free, direct curl

One sentence, p. 336:  "There may still be evidence of post-Flood AND in the ratios of cosmogenic radionuclides which are commonly used for Quaternary dating (Oard, 2021)."  ("AND" is accelerated nuclear decay.)  Recorded because it is the only citation of Oard's cosmogenic work by another young-earth author anywhere, and because it points at the ratio — the burial clock — which is the right place to look and the place nobody has gone.  The page was pinned from the printed folios;  a 2026 audit note gives it as p. 339, which is three pages out.

Thomas 2011 — ICR's only use of ¹⁰Be, and the physics in it

Brian Thomas, "Continents Should Have Eroded Long Ago," Institute for Creation Research, 22 August 2011.  https://www.icr.org/article/continents-should-have-eroded-long/

topic: creationist · camp: creationist · type: popular · clock: exposure · direction: mixed · access: plain curl, HTTP 200

Reports Portenga & Bierman's global ¹⁰Be erosion-rate compilation (GSA Today 21(8): 4–10, 2011) and argues from it that the continents cannot be billions of years old.  Included here for one sentence:  "Geologists have been measuring quantities of ¹⁰Be, an isotope of the element beryllium that becomes radioactive with exposure to the sun.  The more ¹⁰Be that is present at a given site, the longer it has been exposed to the sun without being carried off by erosion."

Wrong twice in one sentence — ¹⁰Be is produced by spallation and is radioactive from the moment it is made, and the agent is the galactic cosmic-ray flux, which solar activity modulates downward.  The erosion-rate argument itself belongs to erosion-rates.  What belongs here is the asymmetry:  ICR's one use of cosmogenic data accepts ¹⁰Be accumulation as a valid clock in order to date the continents, while CRSQ rejects it.

Everything else — a negative finding, corrected and re-established

The earlier version of this page recorded that CRSQ held one on-topic paper, that AiG and ARJ held none, and that Journal of Creation and the ICC proceedings could not be searched.  That last part was the whole of the problem:  the two unsearched archives were the two holding material.  All five venues were swept on 30 August 2026 and the table below is the corrected state.

State of the search as of 30 August 2026.  All five venues are now settled, and the corrected finding is this.  Cosmogenic exposure dating has been engaged by one young-earth author — Oard, in 1997, 2013, 2014 and 2021.  ²⁶Al/¹⁰Be burial dating has been engaged twice, in two short unsigned Creation news items about Sterkfontein, on discordance rather than on the equation.  Nobody has yet addressed the fact that a burial age contains no production rate.

What is still not established.  Whether a Letter answering Oard 2021 exists in a CRSQ Letters column that the EPrints repository does not ingest.  Closing that needs the printed issues, not the repository.

Cross-references, not duplicated here

• html/unpublished-ai/erosion-rates/literature-review.md — the cosmogenic denudation-rate literature (Bierman & Caffee, Portenga & Bierman, Kirchner et al. 2001, the Sadler-effect papers, Twidale's Comment). That article uses the same nuclides for a different quantity and has already catalogued ~30 entries that need not be repeated.
• agents/memory/erosion-rates.md — carries the finding that Oard 2013 rejects cosmogenic methods a priori, and the open question about the CRSQ archive that this file now answers.
• agents/memory/ice-age.md — already logs the absence of creationist engagement with ²⁶Al/¹⁰Be burial isochrons and the Missouri till stack, and Klevberg's multi-method-agreement criterion, which the Missouri result satisfies.
• agents/memory/ice-core-layer-counting.md and decay-free-clocks.md — the ¹⁰Be ice-core record and the Sigl 2015 seven-year error; meteoric ¹⁰Be, not in-situ, but coupled to the same cosmic-ray flux and therefore the natural cross-check on Oard's proposal.
• agents/memory/decay-rate-constancy.md and the RATE material — the accelerated-decay appeal Oard needs for burial dating belongs there, not here.