KArMars: A Breadboard Model for In Situ Absolute Geochronology Based on the K–Ar Method Using UV‐Laser‐Induced Breakdown Spectroscopy and Quadrupole Mass Spectrometry
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Media type:
E-Article
Title:
KArMars: A Breadboard Model for In Situ Absolute Geochronology Based on the K–Ar Method Using UV‐Laser‐Induced Breakdown Spectroscopy and Quadrupole Mass Spectrometry
Description:
<jats:p>We present a breadboard prototype to perform <jats:italic>in situ</jats:italic> dating applicable to planetary exploration. Based on the K–Ar dating method and using instruments inspired by flight‐proven analytical components, ‘KArMars’ ablated a geological sample under high vacuum with a quadrupled ultraviolet (UV at 266 nm) Nd:YAG laser. During ablation, the K content of the target material was given by laser‐induced breakdown spectroscopy and the released <jats:sup>40</jats:sup>Ar was measured with a quadrupole mass spectrometer. Because K was measured as a concentration and <jats:sup>40</jats:sup>Ar as a count of atoms, these values were converted using the ablated mass given by the product of the density and the ablated volume. The uncertainties of the age measurement were < 15%. The quality of the K–Ar measurements was enhanced by the advantages of UV laser ablation such as the minimisation of thermal effects on argon diffusion. This work demonstrates that a specialised instrument inspired by this set‐up could provide <jats:italic>in situ</jats:italic> absolute geochronology with sufficient precision for scientific investigations, particularly where the crater density counting provides higher uncertainties on Mars.</jats:p>