Basaltic volcanism on the angrite parent body: Comparison with 4 Vesta

Abstract

Carbon and nitrogen data from stepped combustion analysis of eight angrites, seven eucrites, and two diogenites, alongside literature data from a further nine eucrites and two diogenites, have been used to assess carbon and nitrogen incorporation and isotope fractionation processes on the angrite parent body (APB), for comparison with volatile behavior on the HED parent body (4 Vesta). A subset of the angrite data has been reported previously (Abernethy et al. 2013). Two separate families of volatile components were observed. They were (1) moderately volatile material (MVM), mostly combusting betweeñ 500 and 750°C and indistinguishable from terrestrial contamination and (2) refractory material (RM), mainly released above 750°C and thought to be carbon (as CO 2À3 ) and nitrogen (as N 2 or NH þ 4 ) dissolved within the silicate lattice, fitting with the slightly oxidized (~IW to IW+2) angrite fO 2 conditions. Isotopic fractionation trends for carbon and nitrogen within the plutonic and basaltic (quenched) angrites suggest that the behavior of the two volatile elements is loosely coupled, but that the fractionation process differs between the two angrite subgroups. Comparison with results from eucrites and diogenites implies similarities between speciation of carbon and nitrogen on 4 Vesta and the APB, with the latter being more enriched in volatiles than the former.

Internal or external magma oceans in the earliest protoplanets – Perspectives from nitrogen and carbon fractionation

“…Lack of EMOs in contemporaneously accreting IMPBs means that alternate mechanisms are required to explain these observations. Accretion of MVE depleted precursors (Tian et al, 2019), impact induced-evaporation (O'Neill and Palme, 2008;Pringle et al, 2014), and surface volcanism (Abernethy et al, 2018) are other mechanisms postulated as explanations for the MVE depletion recorded by HEDs and angrites. Akin to EMO differentiation, the latter two processes also result in surficial vapor-silicate melt exchange albeit post MO differentiation and crystallization.…”

Origin of nitrogen on Mars: First in situ N isotope analyses of martian meteorites

“…Also, eucrites, which are thought to originate from the asteroid Vesta, record δ 15 N values between -54.2 ± 14.1 to -2.6 ± 8.8‰ (Fig. 1; Miura and Sugiura, 1993;Abernethy et al, 2018), as revealed by stepped combustion analyses. Finally, nitrogen in the terrestrial mantle has a δ 15 N value between -40 and -5‰ (Fig.…”

“…Fig. 1: Nitrogen (δ 15 N) and hydrogen (δD) isotopic compositions of different objects and reservoirs of the solar system, i.e., Earth's mantle (i.e., in situ and whole-rock analyses; Deloule, 1991;Cartigny and Marty, 2013;Hallis et al, 2015;Peslier et al, 2017), Mars' mantle (i.e., in situ and whole-rock analyses; Murty et al, 1999;Mathew and Marti, 2001;Gillet et al, 2002;Mohapatra and Murty, 2003;Peslier et al, 2019;Dudley et al, 2022), the angrite parent body (APB) (in situ and whole-rock analyses; Abernethy et al, 2013Abernethy et al, , 2018Deligny et al, 2021), Vesta (i.e., the parent body of howardites, eucrites, and diogenites (HEDs); in situ and whole-rock analyses; Miura and Sugiura, 1993;Abernethy et al, 2018;Stephant et al, 2021), enstatite chondrites (i.e., whole-rock analysis; Kung and Clayton, 1978;Grady et al, 1986;, ordinary chondrites (i.e., whole-rock analysis; McNaughton et al, 1982;Sugiura and Hashizume, 1992;Hashizume et Sugiura, 1995;Alexander et al, 2012;Piani et al, 2021 and references therein), carbonaceous chondrites (i.e., whole-rock analysis; Boato, 1954;Kung and Clayton, 1978;McNaughton et al, 1982;Kerridge, 1985;Grady et al, 1986;Pearson et al, 2001Pearson et al, , 2006Alexander et al, 2012Alexander et al, , 2018Vacher et al, 2020;Piani et al, 2020, 2021 andreferences therein)…”

Nitrogen isotope evidence for Earth’s heterogeneous accretion of volatiles

“…However, even oxidized planetesimals may have undergone severe evaporative volatile loss, if the surface magma ocean lasted sufficiently long. Iron meteorites contain a few ppm to 200 ppm N 21 , whereas basalts in asteroids may contain up to 10 ppm N 68 . However, both iron meteorites and asteroid basalts may have experienced extensive volatile loss, considering the pressure-dependence of N solubility in both metallic and silicate melts 37,69 .…”