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Title: In situ dating on Mars: A new approach to the K–Ar method utilizing cosmogenic argon

Abstract

In this paper, cosmogenic argon isotopes are produced in feldspars via nuclear reactions between cosmic rays and Ca and K atoms within the lattice. These cosmogenic isotopes can be used as proxies for K and Ca, much like nuclear reactor-derived 39Ar and 37Ar are used as proxies for K and Ca, respectively, in 40Ar/39Ar geochronology. If Ca and K are uniformly distributed, then the ratio of radiogenic 40Ar (40Ar*) to cosmogenic 38Ar or 36Ar (38Arcos or 36Arcos) is proportional to the difference between the radioisotopic and exposure ages, as well as the K/Ca ratio of the degassing phase. Thus cosmogenic, radiogenic, and trapped Ar isotopes, all of which can be measured remotely and are stable over geologic time, are sufficient to generate an isochron-like diagram from which the isotopic composition of the trapped component may be inferred. Finally, such data also provide a means to assess the extent to which the system has remained closed with respect to 40Ar*, thereby mitigating otherwise unquantifiable uncertainties that complicate the conventional K–Ar dating method.

Authors:
 [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1438660
Report Number(s):
LLNL-JRNL-636235
Journal ID: ISSN 0094-5765; TRN: US1900477
Grant/Contract Number:  
AC52-07NA27344
Resource Type:
Accepted Manuscript
Journal Name:
Acta Astronautica
Additional Journal Information:
Journal Volume: 94; Journal Issue: 1; Journal ID: ISSN 0094-5765
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; 79 ASTRONOMY AND ASTROPHYSICS; Mars; geochronology; argon; cosmogenic

Citation Formats

Cassata, William S. In situ dating on Mars: A new approach to the K–Ar method utilizing cosmogenic argon. United States: N. p., 2013. Web. https://doi.org/10.1016/j.actaastro.2013.07.040.
Cassata, William S. In situ dating on Mars: A new approach to the K–Ar method utilizing cosmogenic argon. United States. https://doi.org/10.1016/j.actaastro.2013.07.040
Cassata, William S. Thu . "In situ dating on Mars: A new approach to the K–Ar method utilizing cosmogenic argon". United States. https://doi.org/10.1016/j.actaastro.2013.07.040. https://www.osti.gov/servlets/purl/1438660.
@article{osti_1438660,
title = {In situ dating on Mars: A new approach to the K–Ar method utilizing cosmogenic argon},
author = {Cassata, William S.},
abstractNote = {In this paper, cosmogenic argon isotopes are produced in feldspars via nuclear reactions between cosmic rays and Ca and K atoms within the lattice. These cosmogenic isotopes can be used as proxies for K and Ca, much like nuclear reactor-derived 39Ar and 37Ar are used as proxies for K and Ca, respectively, in 40Ar/39Ar geochronology. If Ca and K are uniformly distributed, then the ratio of radiogenic 40Ar (40Ar*) to cosmogenic 38Ar or 36Ar (38Arcos or 36Arcos) is proportional to the difference between the radioisotopic and exposure ages, as well as the K/Ca ratio of the degassing phase. Thus cosmogenic, radiogenic, and trapped Ar isotopes, all of which can be measured remotely and are stable over geologic time, are sufficient to generate an isochron-like diagram from which the isotopic composition of the trapped component may be inferred. Finally, such data also provide a means to assess the extent to which the system has remained closed with respect to 40Ar*, thereby mitigating otherwise unquantifiable uncertainties that complicate the conventional K–Ar dating method.},
doi = {10.1016/j.actaastro.2013.07.040},
journal = {Acta Astronautica},
number = 1,
volume = 94,
place = {United States},
year = {2013},
month = {8}
}

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Works referenced in this record:

A laser desorption resonance ionization mass spectrometer for Rb-Sr geochronology: Sr isotope results
conference, March 2012


Argon-39-argon-40 “ages” and trapped argon in Martian shergottites, Chassigny, and Allan Hills 84001
journal, May 1999


K-Ar dating of rocks on Mars: Requirements from Martian meteorite analyses and isochron modeling
journal, January 2009


Argon diffusion in plagioclase and implications for thermochronometry: A case study from the Bushveld Complex, South Africa
journal, November 2009

  • Cassata, William S.; Renne, Paul R.; Shuster, David L.
  • Geochimica et Cosmochimica Acta, Vol. 73, Issue 21
  • DOI: 10.1016/j.gca.2009.07.017

Evidence for shock heating and constraints on Martian surface temperatures revealed by 40Ar/39Ar thermochronometry of Martian meteorites
journal, December 2010

  • Cassata, William S.; Shuster, David L.; Renne, Paul R.
  • Geochimica et Cosmochimica Acta, Vol. 74, Issue 23
  • DOI: 10.1016/j.gca.2010.08.027

Argon diffusion in pyroxenes: Implications for thermochronometry and mantle degassing
journal, April 2011

  • Cassata, William S.; Renne, Paul R.; Shuster, David L.
  • Earth and Planetary Science Letters, Vol. 304, Issue 3-4
  • DOI: 10.1016/j.epsl.2011.02.019

In situ geochronology as a mission-enabling technology
conference, March 2012


Petrology and chemistry of MIL 03346 and its significance in understanding the petrogenesis of nakhlites on Mars
journal, April 2006


Volatile Analysis by Pyrolysis of Regolith for planetary resource exploration
conference, March 2012


Neon diffusion kinetics in olivine, pyroxene and feldspar: Retentivity of cosmogenic and nucleogenic neon
journal, June 2012


Solar and cosmogenic argon in dated lunar impact spherules
journal, March 2007

  • Levine, Jonathan; Renne, Paul R.; Muller, Richard A.
  • Geochimica et Cosmochimica Acta, Vol. 71, Issue 6
  • DOI: 10.1016/j.gca.2006.11.034

Overview of NASA Program on Development of Radioisotope Power Systems with High Specific Power
conference, June 2006

  • Misra, Ajay
  • 4th International Energy Conversion Engineering Conference and Exhibit (IECEC)
  • DOI: 10.2514/6.2006-4187

Persistence and origin of the lunar core dynamo
journal, May 2013

  • Suavet, C.; Weiss, B. P.; Cassata, W. S.
  • Proceedings of the National Academy of Sciences, Vol. 110, Issue 21
  • DOI: 10.1073/pnas.1300341110

A Long-Lived Lunar Core Dynamo
journal, January 2012


Quantitative laser-induced breakdown spectroscopy of potassium for in-situ geochronology on Mars
journal, April 2012

  • Stipe, Christopher B.; Guevara, Edward; Brown, Jonathan
  • Spectrochimica Acta Part B: Atomic Spectroscopy, Vol. 70
  • DOI: 10.1016/j.sab.2012.04.010

In situ radiometric dating on Mars: Investigation of the feasibility of K-Ar dating using flight-type mass and X-ray spectrometers
journal, September 2009


Variability of diffusion of argon in albite, pyroxene, and olivine in shocked and unshocked samples
journal, January 2012


Cosmic-Ray-Produced Noble Gases in Meteorites
journal, January 2002