DOI: 10.5061/dryad.gf1vhhmwx
title: A heterogenous mantle and crustal structure formed during the early differentiation of Mars

description: Highly siderophile element abundances and Os isotopes of nakhlite and
 chassignite meteorites demonstrate that they represent a comagmatic suite
 from Mars. Nakhlites experienced variable assimilation of &gt;2 Ga
 altered high Re/Os basaltic crust. This basaltic crust is distinct from
 the ancient crust represented by meteorites Allan Hills 84001, or
 impact-contaminated Northwest Africa 7034/7533. Nakhlites and chassignites
 that did not experience crustal assimilation were extracted from a
 depleted lithospheric mantle distinct from the deep plume source of
 depleted shergottites. The comagmatic origin for nakhlites and
 chassignites demonstrates a layered martian interior comprising ancient
 enriched basaltic crust derived from trace element-rich shallow magma
 ocean cumulates, a variably metasomatized mantle lithosphere, and a trace
 element-depleted deep mantle sampled by plume magmatism.
description: Major and trace element abundance determinations and
 sources New major and trace element abundance
 data are reported for nakhlite Y-000802 and ALH 84001 (<em>Table
 S2</em>). The data were obtained in an identical way to previously
 reported data by our group on nakhlites and chassignites (e.g.,
 <em>[14,16,25,32]) </em>at the <em>Scripps Isotope
 Geochemistry Laboratory (SIGL)</em>. This included the digestion of
 a 50 mg aliquot from a larger mass of sample powder (1 to 2g) also used
 for Re-Os isotope and HSE abundance analysis. Complete digestion was
 accomplished by sealing the sample with Teflon-distilled 27.5M HF (4 mL)
 and 15.7M HNO<sub>3</sub> (1 mL) in closed-capped Teflon
 beakers for &gt;72 hrs on a hotplate at 150°C, along with total
 procedural blanks and terrestrial basalt and andesite reference materials
 (BHVO-2, BCR-2, BIR-1a, AGV-2). Samples were sequentially dried and taken
 up in concentrated HNO<sub>3</sub> to destroy fluorides,
 followed by doping with indium to monitor instrumental drift during
 analysis and then diluted to a factor of 5,000. Trace-element abundances
 were determined using a <em>ThermoScientific </em>iCAP Qc
 quadrupole inductively coupled plasma mass spectrometer (ICP-MS) and all
 data are blank-corrected. Long-term reproducibility of abundance data is
 better than 6% for most elements, except for Mo, Te, and Se
 (&gt;10%). Osmium isotope and highly
 siderophile element (Re, Pd, Pt, Ru, Ir, Os)
 abundances Osmium isotope and HSE abundance
 analyses were performed at the <em>SIGL </em>on precisely
 weighed aliquots of homogenized powder that were then digested in 10 cm
 sealed borosilicate Carius tubes with isotopically enriched multi-element
 spikes (<sup>99</sup>Ru, <sup>106</sup>Pd,
 <sup>185</sup>Re, <sup>190</sup>Os,
 <sup>191</sup>Ir, <sup>194</sup>Pt), and 7 mL of a
 1:2 mixture of multiply Teflon distilled HCl and
 HNO<sub>3</sub> purged of excess Os by repeated treatment and
 reaction with H<sub>2</sub>O<sub>2</sub>. Samples
 were digested to a maximum temperature of 270˚C in an oven for 72 hours.
 Osmium was triply extracted from the acid using
 CCl<sub>4</sub> and then back extracted into HBr, prior to
 purification by micro-distillation. Rhenium and the other HSE were
 recovered and purified from the residual solutions using standard anion
 exchange separation techniques <em>(47)</em>. Isotopic
 compositions of Os were measured in negative-ion mode using a
 <em>ThermoScientific</em> Triton thermal ionization mass
 spectrometer in peak-jumping mode on the secondary electron multiplier.
 Rhenium, Pd, Pt, Ru, and Ir were measured using a <em>Cetac
 Aridus</em> II desolvating nebuliser coupled to a
 <em>ThermoScientific </em>iCAPQc ICP-MS. Offline corrections
 for Os involved an oxide correction, an iterative fractionation correction
 using <sup>192</sup>Os/<sup>188</sup>Os = 3.08271
 and assuming the exponential law, a <sup>190</sup>Os spike
 subtraction, and an Os blank subtraction. Precision for
 <sup>187</sup>Os/<sup>188</sup>Os, determined by
 repeated measurement of a 35 pg UMCP Johnson-Matthey standard solution was
 better than ±0.2% (2 SD; 0.11381 ±12; <em>n</em> = 12).
 Rhenium, Ir, Pt, Pd, and Ru isotopic ratios for sample solutions were
 corrected for mass fractionation using the deviation of the standard
 average run on the day over the natural ratio for the element. External
 reproducibility for HSE analyses was better than 0.5% for 0.5 ppb
 solutions and all reported values are blank corrected. The total
 procedural blanks (<em>n</em> = 3) run with the samples gave
 <sup>187</sup>Os/<sup>188</sup>Os = 0.150 ± 0.012,
 with quantities (in picograms) of 2.5 [Re], 27 [Pd], 3.1 [Pt], 16 [Ru],
 0.3 [Ir] and 0.3 [Os]. Blanks contributions are listed in <em>Table
 S3</em> and resulted in negligible corrections for most elements
 within samples (&lt;5%), unless noted in the table.
description: # A heterogenous mantle and crustal structure formed during the early
 differentiation of Mars
 [https://doi.org/10.5061/dryad.gf1vhhmwx](https://doi.org/10.5061/dryad.gf1vhhmwx) Data are provided for major and trace element abundances, as well as new Re-Os isotope and highly sideophile element abundances (Os, Ir, Ru, Pt, Pd, Re) for nakhlites, chassignites and the martian meteorite ALH 84001. ## Description of the data and file structure Data are provided in five supplementary tables. Table S1 shows the new Re-Os isotope and HSE abundance data. Table S2 includes both published and new major- and trace-element abundance data. Table S3 shows the percentage blank additions for new data in Table S1. Table S4 provides the full published data for Re-Os isotopes and HSE abundances in nakhlites, chassignites, and ALH 84001. Table S5 provides Os and S isotope data shown in the manuscript. ## Sharing/Access information Data was derived from the following sources: * This work * \[For Tables S4 and S5 hosted as Supplemental Information]: Brandon, A.D., Walker, R.J., Morgan, J.W., Goles, G.G. (2000). Re-Os isotopic evidence for early differentiation of the Martian mantle. Geochimica et Cosmochimica Acta, 64, 4083-4095. Jones, J.H., Neal, C.R., Ely, J.C. (2003) Signatures of the highly siderophile elements in the SNC meteorites and Mars: a review and petrologic synthesis. Chemical Geology, 196, 5-25 Dale, C.W., Burton, K.W., Greenwood, R.C., Gannoun, A., Wade, J., Wood, B.J. and Pearson, D.G. (2012) Late accretion on the earliest planetesimals revealed by the highly siderophile elements. Science, 336, 72-75. Mari, N., Riches, A.J.V., Hallis, L.J., Marrocchi, Y., Villeneuve, J., Gleissner, P., Becker, H. and Lee, M.R. (2019). Syneruptive incorporation of martian surface sulphur in the nakhlite lava flows revealed by S and Os isotopes and highly siderophile elements: implication for mantle sources in Mars. Geochimica et Cosmochimica Acta, 266, 416-434. Farquhar, J., Kim, S.T., Masterson, A. (2007) Implications from sulfur isotopes of the Nakhla meteorite for the origin of sulfate on Mars. Earth and Planetary Science Letters, 264, 1-8. Dottin, J.W., Labidi, J., Farquhar, J., Piccoli, P., Liu, M.C., McKeegan, K.D. (2018) Evidence for oxidation at the base of the nakhlite pile by reduction of sulfate salts at the time of lava emplacement. Geochimica et Cosmochimica Acta, 239, 186-197. Greenwood, J.P., Riciputi, L.R., McSween Jr, H.Y., Taylor, L.A. (2000) Modified sulfur isotopic compositions of sulfides in the nakhlites and Chassigny. Geochimica et Cosmochimica Acta, 64, 1121-1131. Franz, H.B., Kim, S.-T., Farquhar, J., Day, J.M.D., Economos, R.C., McKeegan, K.D., Schmitt, A.K., Irving, A.J., Hoek, J., Dottin, J. (2014) Sulphur isotopic signature links atmospheric chemistry to sulfur assimilation by martian magmas. Nature, 508, 364-367.