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Dating phosphogenesis with strontium isotopes
Geochimica et Cosmochimica Acta, 1990Authigenic and replacement francolites in modern phosphorite have values of {sup 87}Sr/{sup 86}Sr within error of that of modern marine Sr (0.70916 {plus minus} 2). During the phosphatisation of carbonate, Sr is not inherited from the carbonate but is totally exchanged with Sr in ambient water. The {sup 87}Sr/{sup 86}Sr in shallow marine pore waters is
J.M McArthur +4 more
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Strontium Isotopes In Seawater Through Time
Annual Review of Earth and Planetary Sciences, 1989where pis the p-particle, v is an antineutrino, and Q represents the decay energy (0.275 MeV). The recommended decay constant for 87Rb is 1.42 x 10-11 yr-I (Steiger & Jager 1977), and its half-life T is therefore 48.8 Gyr. On geological time scales, the isotopes 84, 86, and 88 are stable, in contrast to 87Sr, and their abundance ratios are therefore ...
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Isotope exchange of strontium and molybdate ions in strontium polymolybdates
Journal of Radioanalytical and Nuclear Chemistry, 2002The heterogeneous isotopic exchange reactions in strontium polymolybdates of Sr2+ and MoO42- ions in the strontium nitrate and sodium molybdate solutions have been studied using 90Sr and 99Mo as tracers. Electrometric methods have been used to study the compositions of strontium molybdates obtained by adding strontium chloride to a progressively ...
G. Atun, N. Bodur
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Radiochemical separation of strontium by isotopic exchange
Talanta, 1967Isotopic exchange has been used for the rapid separation of minute quantities of radio-strontium. A number of variables such as agitation time, concentration of strontium in both phases, mode of preparation and aging of the precipitates, were studied and optimized.
I H, Qureshi, M S, Shahdo, S M, Hasany
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Strontium Isotope Fractionation in the Kiglapait Intrusion
Science, 1983The initial ratio of strontium-87 to strontium-86 rises systematically from 0.70395 to 0.70662 over the upper 10 percent of the Kiglapait layered intrusion. This ratio is strongly correlated with potassium and rubidium. Contamination, exchange, and magma mixing fail to account for the increase, which is ascribed to the imperfect retention of radiogenic
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