High-Resolution Analyses of Lunar and Martian Samples, and Impactor Material from the Chicxulub Basin Using ICP-MS

Inductively coupled plasma mass spectrometry (ICP-MS) has been a widely used analytical method across many scientific disciplines since the mid-90’s for several reasons. It has the capability to determine the abundances for most elements of the periodic table and has a sensitivity down to parts per trillion (ppt) levels in certain cases. Liquid samples are readily introduced to the instrument subsequent acid digestions and solid samples can be analyzed via laser ablation prior to analysis. These broad and flexible analytical capabilities are coupled with relatively low costs for the instrument which means that these methods are viable for even small laboratories. One caviot to ICP-MS is that there are instances when the recombination of lighter elements can be sorted by mass as a heavier isotope. Since ICP-MS fundamentally sorts elements by mass this recombination of lighter elements can artificially inflate the signal on a heavier element of interest. This research provides a method to quantify and correct for this phenomenon, then applies the method to a suite of lunar samples and terrestrial impact samples to correct any artificial inflation of a signal for a suite of moderately volatile elements (MVEs) during a procedural run. These elements are capable of tracking high-temperature degassing events on planetary bodies, and the resulting analyses have shown that a catastrophic degassing event occurred late in the Moon’s evolution. ICP-MS analyses on material recovered from the Chicxulub Impact Basin have indicated that platinum group elements are more concentrated in clast-free impact melt than other impact lithologies. While the horizon transitioning from pre- to post-impact sediments has a distinct PGE signature, the impact melt lithologies that are far deeper in the recovered core retain more of the PGE derived impactor signature