Publication Date:
2016-04-23
Description:
We present a new breadboard prototype to perform in situ dating applicable to planetary exploration. Based on the K-Ar dating method and using instruments inspired by analytical components already flight proven, ‘KArMars’ ablates a geological sample under high vacuum with a quadrupled ultraviolet (UV at 266 nm) Nd:YAG laser. During the ablation, the K content of the ablated material is given by laser induced breakdown spectroscopy and the ablation frees the 40 Ar, which is measured with a quadrupole mass spectrometer. Because the K is a concentration and 40 Ar is a count of atoms, these values must be converted using the ablated mass given by the product of the density and the ablated volume. The uncertainties of the age measurement are less than 15%. The quality of the K-Ar measurements is enhanced by the advantages of the UV laser concerning the ablation such as the minimisation of the thermal effects on argon diffusion. This work demonstrates that a specialised instrument inspired by this set-up could provide in situ absolute geochronology with sufficient precision for scientific investigations, particularly where the crater density counting provides higher uncertainties on Mars. This article is protected by copyright. All rights reserved.
Print ISSN:
1639-4488
Electronic ISSN:
1751-908X
Topics:
Geosciences
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