Xenon and other noble gases in shergottites

Noble gases and nitrogen in Tissint reveal the composition of the Mars atmosphere

“…40 Ar/ 36 Ar ratios from this study and from in situ measurements reported in Mahaffy et al (2013 Conrad et al (2016). Krypton values from Swindle et al (1986). Errors correspond to 1σ.…”

“…Xe isotope spectra corrected for terrestrial Xe, for 1 Myr and 0.7 Myr of cosmic-ray exposure are also shown. (b) Isotope spectra of Kr extracted from sample glass compared to results obtained on lithology C (glass) of the EETA79001 meteorite (Swindle et al, 1986) and in situ by MSL (Conrad et al, 2016). Terrestrial Kr (Ozima and Podosek, 2002) is shown for comparison.…”

Martian xenon components in Shergotty mineral separates: Locations, sources, and trapping mechanisms

“…This is in contrast to Queen Alexandra Range (QUE) 94201, the meteorite with the lowest crustal component, which has oxygen fugacity close to the iron-wüstite buffer (Herd and Papike 2000) and higher ε Nd (Borg et al 1997). Figure 1 uses literature data to illustrate the variations in the bulk xenon isotope signatures of the basaltic shergottites (Swindle et al 1986;Ott 1988;Terribilini 2000;Marti 2001, 2002;Mathew et al 2003). Xenon isotope systematics of martian meteorites typically reveal a mixing between a martian atmospheric signature (Shergottite Parent Body; Swindle et al 1986) and one or more interior components.…”

“…Figure 1 uses literature data to illustrate the variations in the bulk xenon isotope signatures of the basaltic shergottites (Swindle et al 1986;Ott 1988;Terribilini 2000;Marti 2001, 2002;Mathew et al 2003). Xenon isotope systematics of martian meteorites typically reveal a mixing between a martian atmospheric signature (Shergottite Parent Body; Swindle et al 1986) and one or more interior components. The xenon isotopic signature of the martian atmosphere, identified in shergottite melt glass and in Nakhla, is distinguished by an elevated 129 Xe/ 132 Xe ratio of 2.40 ± 0.02 (Swindle et al 1986).…”

Pre-Global Surveyor evidence for Martian ground water

“…These observations actually are the culmination of a series of discoveries strongly suggesting the presence in the Martian crust of liquid water that interacts efficiently with the atmosphere. This evidence involves the presence of modified minerals in Martian meteorite samples that require the intervention of liquid water (2)(3)(4) and, in particular, measurements of the D͞H ratios in hydrous minerals created hundreds of millions of years ago (5) that can be virtually identical with the atmospheric D͞H ratio at the present time (6). † It has been argued that this surprising result requires efficient exchange of water between the atmosphere and an underground reservoir containing much more water than the atmosphere, such that the amount of hydrogen and deuterium lost by escape from space over the past several hundred millions of years is small compared with that in the underground (or polar-cap) reservoirs (7,8).…”