Instrumentation development for In Situ 40Ar/ 39 Ar planetary geochronology

Geostandards and Geoanalytical Research
By: , and 



The chronology of the Solar System, particularly the timing of formation of extra-terrestrial bodies and their features, is an outstanding problem in planetary science. Although various chronological methods for in situ geochronology have been proposed (e.g., Rb-Sr, K-Ar), and even applied (K-Ar), the reliability, accuracy, and applicability of the 40Ar/39Ar method makes it by far the most desirable chronometer for dating extra-terrestrial bodies. The method however relies on the neutron irradiation of samples, and thus a neutron source. Herein, we discuss the challenges and feasibility of deploying a passive neutron source to planetary surfaces for the in situ application of the 40Ar/39Ar chronometer. Requirements in generating and shielding neutrons, as well as analysing samples are described, along with an exploration of limitations such as mass, power and cost. Two potential solutions for the in situ extra-terrestrial deployment of the 40Ar/39Ar method are presented. Although this represents a challenging task, developing the technology to apply the 40Ar/39Ar method on planetary surfaces would represent a major advance towards constraining the timescale of solar system formation and evolution.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Instrumentation development for In Situ 40Ar/39Ar planetary geochronology
Series title Geostandards and Geoanalytical Research
DOI 10.1111/ggr.12170
Volume 41
Issue 3
Year Published 2017
Language English
Publisher Wiley
Contributing office(s) Central Mineral and Environmental Resources Science Center
Description 16 p.
First page 381
Last page 396