Molecular modeling of the effects of 40Ar recoil in illite particles on their K–Ar isotope dating

Abstract

International audienc

Research of CO2 and N2 Adsorption Behavior in K-Illite Slit Pores by GCMC Method

“…The K-illite is represented by pyrophyllite-1Tc1920 with the unit cell formula of K x [Si (8-x) Al x ](Al 4 )O 20 (OH) 4 21. In each unit cell one silicon (Si) is substituted by one aluminum (Al) in the tetrahedral sheet ( x  = 1), causing of −1.0 e charge per unit cell.…”

XRD-based 40Ar/39Ar age correction for fine-grained illite, with application to folded carbonates in the Monterrey Salient (northern Mexico)

“…Illite is one of the few K-bearing minerals that form under diagenetic and anchizonal conditions ( Fig. 1a) and has the capacity of retaining radiogenic argon ( 40 Ar*) in its structure after natural recoil (i.e., 40 Ar* nm-scale displacement during 40 K spontaneous radioactive decay, Zimmermann and Odin, 1982;Szczerba et al, 2015) at low temperature (Hassanipak and Wampler, 1996;Clauer et al, 1997;Sletten and Onsttot, 1998). 40 Ar*/ 39 Ar dating is a variant of the K-Ar dating method that allows for the analysis of small amount of samples with high precision (van der Pluijm et al, 2001;Clauer, 2012).…”

“…1, Beckinsale and Gale, 1969). Recently, Szczerba et al (2015) demonstrated, using molecular dynamics simulations, that some dislocation of 40 Ar* is possible within illite due to the decay of 40 K, but the net loss is expected to be very small for all but the smallest of illite particles (<0.02µm in diameter and less than five illite fundamental layers). For 40 Ar*/ 39 Ar dating, the K content is estimated by producing 39 Ar in a nuclear reactor using the fast neutron reaction 39 K (n,p) 39 Ar (Merrihue and Turner, 1966).…”

Petrochronology of the Terre Adélie Craton (East Antarctica) evidences a long-lasting Proterozoic (1.7–1.5 Ga) tectono-metamorphic evolution — Insights for the connections with the Gawler Craton and Laurentia

“…This event is exhibited by the complex spectra of amphibolite sample JJP98-51, with experiment D8-1 (Fig. 18), which may result from an Ar recoil effect due to the altered state of amphiboles ( 40 Ar* nm-scale displacement during 40 K spontaneous radioactive decay; Zimmermann and Odin, 1982;Szczerba et al, 2015). In contrast, experiment D8-2 experiment (Fig.…”