Noble gases anomalies in terrestrial ores and meteorites
type: CreativeWork
description: "Analyses of the content and isotopic composition of xenon and krypton in terrestiral ores containing tellurium, selenium or iodine resulted in the following conclusions: 1. The double beta-decay half-life for ¹³⁰Te is 2.51 x 10²¹ years from analysis of tellurobismuthite from Boliden, Sweden and 2.83 x 10²¹ years from analysis of tellurides from Kalgoorlie, Australia. 2. The ratio of the double beta-decay half-life of ¹²⁸Te relative to that of ¹³⁰Te is ≥ 108 and ≥ 293 for Boliden tellurobismuthite and Kalgoorlie tellurides, respectively. 3. Selenium minerals and tellurium ores containing selenium exhibit ⁸²Kr excess attributed to the double beta-decay of ⁸²Se. Preliminary half -life value for this decay is (2-4)10²⁰ years. 4. The formation of excesses of ¹²⁹Xe and ¹³¹Xe in tellurium ores and excess ⁸³Kr in selenium ores result from nuclear reactions on tellurium and selenium, respectively. 5. The excess ¹²⁹Xe in iodyrite (silver iodide) is from the in situ decay of ¹²⁹I incorporated in the ore during its formation. From the observed isotopic composition of xenon, it is calculated that prior to the nuclear age, the equilibrium ratio of ¹²⁹I/¹²⁷ was between 2.2 x 10⁻¹⁵ and 3.3 x 10⁻¹⁵. 6. Measurements of the ¹³⁰Xe, formed from the decay of ¹³⁰Te, and the tellurium content allow the age determination of hydrothermal deposits of tellurium by the ¹³⁰Te-¹³⁰Xe dating method. The ages of three telluride samples obtained by this new dating technique agree with geologic age estimates. Application of the neutron irradiation method of ¹²⁹I-¹²⁹Xe dating to chondrules and matrix of Bjurböle meteorite reveal the following: 1. The ¹²⁹I/¹²⁷ ratios incorporated in the Bjurböle chondrules and matrix are identical thereby indicating that these fractions are contemporaneous within ± 1. 5 x 10⁶ years. 2. The method of ¹²⁹I-¹²⁹Xe age determination by the neutron irradiation method is dependent on the intensity of the neutron flux. The release pattern of iodine-correlated ¹²⁹Xe is altered …
abstract: "Analyses of the content and isotopic composition of xenon and krypton in terrestiral ores containing tellurium, selenium or iodine resulted in the following conclusions: 1. The double beta-decay half-life for ¹³⁰Te is 2.51 x 10²¹ years from analysis of tellurobismuthite from Boliden, Sweden and 2.83 x 10²¹ years from analysis of tellurides from Kalgoorlie, Australia. 2. The ratio of the double beta-decay half-life of ¹²⁸Te relative to that of ¹³⁰Te is ≥ 108 and ≥ 293 for Boliden tellurobismuthite and Kalgoorlie tellurides, respectively. 3. Selenium minerals and tellurium ores containing selenium exhibit ⁸²Kr excess attributed to the double beta-decay of ⁸²Se. Preliminary half -life value for this decay is (2-4)10²⁰ years. 4. The formation of excesses of ¹²⁹Xe and ¹³¹Xe in tellurium ores and excess ⁸³Kr in selenium ores result from nuclear reactions on tellurium and selenium, respectively. 5. The excess ¹²⁹Xe in iodyrite (silver iodide) is from the in situ decay of ¹²⁹I incorporated in the ore during its formation. From the observed isotopic composition of xenon, it is calculated that prior to the nuclear age, the equilibrium ratio of ¹²⁹I/¹²⁷ was between 2.2 x 10⁻¹⁵ and 3.3 x 10⁻¹⁵. 6. Measurements of the ¹³⁰Xe, formed from the decay of ¹³⁰Te, and the tellurium content allow the age determination of hydrothermal deposits of tellurium by the ¹³⁰Te-¹³⁰Xe dating method. The ages of three telluride samples obtained by this new dating technique agree with geologic age estimates. Application of the neutron irradiation method of ¹²⁹I-¹²⁹Xe dating to chondrules and matrix of Bjurböle meteorite reveal the following: 1. The ¹²⁹I/¹²⁷ ratios incorporated in the Bjurböle chondrules and matrix are identical thereby indicating that these fractions are contemporaneous within ± 1. 5 x 10⁶ years. 2. The method of ¹²⁹I-¹²⁹Xe age determination by the neutron irradiation method is dependent on the intensity of the neutron flux. The release pattern of iodine-correlated ¹²⁹Xe is altered …
author: Srinivasan, B.
keywords: Chemistry
date published: 2016-02-10T08:00:00Z
date modified: 2026-07-24T03:19:38Z
provider: Missouri University of Science and Technology
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Missouri--Rolla