© Cedarville University International Conference on Creationism. The views expressed in this publication are those of the author(s) and do not necessarily represent those of Cedarville University. Mogk, N. 2023. Tapping the hourglass: Disequilibrium relaxation following accelerated nuclear decay. In J.H. Whitmore (editor), Proceedings of the Ninth International Conference on Creationism, pp. 327-345. Cedarville, Ohio: Cedarville University International Conference on Creationism. TAPPING THE HOURGLASS: DISEQUILIBRIUM RELAXATION FOLLOWING ACCELERATED NUCLEAR DECAY Nathan Mogk, Independent researcher, Tucson, AZ nm8911@gmail.com ABSTRACT In 2005, the Radioisotopes and the Age of the Earth (RATE) research initiative published compelling evidence for at least one episode of past radioactive decay which was accelerated by orders of magnitude compared with the rates measured in recent years. Constancy of radioactive decay rates is a central assumption in radiometric dating. Accelerated nuclear decay (AND) causes systematic change in the results of radiometric dating beyond the above normal in situ accumulation of daughter products. This includes relaxation of magma reservoirs to equilibrium and excessive inheritance arising from disequilibrium excesses of daughter products of greater order than crystal-melt partition ratios. Uncertainties associated with these mechanisms are shown to disproportionately affect “old” magma reservoirs and magmatic systems that persist after the end of the accelerated nuclear decay epoch. This paper continues the RATE research by developing a mathematical formalism and deriving several significant equations covering nuclear decay acceleration factors, primordial signature, inheritance, mixing, relaxation to equilibrium, sampling, and measurement which are different from the equivalent relations under the standard assumptions of constant decay rates. This paper identifies steps needed to produce a model of acceleration factors over time that enables the recovery of absolute dates from isotopic analysis under certain circumstances when properly constrained by ongoing and future radiometric and geologic observations. Also discussed are the appropriate conditions and usage for corrected absolute radiometric dating and relatively accurate dating. Statistical variation of isotopes in rocks, discordance, and secular equilibrium data are required for constraining accelerated nuclear decay histories within and across radioisotope systems. The San Francisco Volcanic field is identified as a location with appropriate geological context and some existing radiometric dates to test for the existence of the reservoir relaxation mechanism. KEYWORDS accelerated nuclear decay, radiometric dating, excess argon, reservoir relaxation, relative dating, inheritance, corrected dating, partition ratios I. INTRODUCTION A. Partitioning and extraneous decay products Radiometric dating techniques depend on the assumptions of closed system behavior of the rock or mineral to be dated as well as low incorporation of non-radiogenic daughter isotopes to produce reliable dates. (In the case of K-Ar and Ar-Ar dating, zero age is equivalent to an atmospheric Ar isotopic composition (McDougall and Harrison, 1999).) Isochron, laser spot, and step-heating methods are able to partially deal with issues arising from violations of these assumptions, but model ages, which remain by far the most common methodology, depend on the assumption of low extraneous daughter products (Kelley, 2002b). The discussion in this paper is applicable to any radioisotope dating method, but emphasis will be put on the K-Ar system with minor emphasis on the U-Pb system in zircon due to the availability of relevant data and long histories of detailed study. Extraneous daughter products include isotopes inherited from the mantle source reservoir as well as excess incorporated through processes other than in situ radioactive decay. The ratio of the concentration of an element in a melt or hydrothermal fluid versus in a mineral is known as the partition coefficient. Radioistope systems used for dating were chosen to have small partition coefficients in commonly dated minerals to ensure that the assumptions required by the techniques were met. In the case of Ar in olivine and clinopyroxene, Ar can be incorporated in the crystal at a ratio of 10˗3 (Heber et al., 2007), and at ratios of < 10˗2 in a variety of other minerals (Jackson et al. 2021). In zircon, the partition coefficient of Pb directly grown from melt can be as small as 10˗6, up to as high as 10˗3 depending on the availability of charge balancing ions. When grown from aqueous solutions onto crystal seeds, the coefficient can be as high as 0.25 (Watson et al., 1997). Incorporation of extraneous Ar during crystallization has been demonstrated, and can produce age results that are indistinguishable from a valid age (Scibiorski et al., 2021). Ar in its various mineral contexts and Pb in zircon have some of the smallest partition coefficients for daughter isotopes used in radiometric dating. The partition coefficients directly drive the mechanisms described in this paper, so isotopes with larger partition coefficients are more strongly affected. All are too large to overcome 9th 2023
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