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Phosphate in pallasites may thus have formed through the consumption of apatites during pro-grade metamorphism, melting, and melt extraction. Rare earth element (REE) contents of pallasite phosphate grains range from concentrations typically measured for chondritic or primitive achondrite-like phosphates to more (light) REE-depleted signatures, revealing the overall primitive nature of the melts from which the phosphate minerals crystallized. Additionally, principle component analysis of laterally resolved multi-element concentration data of pallasite olivine provides an independent measure of the genetic relationships between the different main group pallasites within their parent body (−ies). This likely results from a spinel-type charge-balancing substitution mechanism in pallasite olivine. Concentrations of Cr and Al are correlated both within single olivine crystals and between olivine crystals of different pallasites, forming a 1:1 linear trend. Oscillatory zoning in an olivine crystal from Imilac provides strong evidence for the olivine not being a restite of partial melting, but rather having crystallized from a melt. The element distribution maps reveal complex zoning in pallasite olivine, which can be explained based on i) diffusion gradients formed during olivine cooling, ii) the crystal chemistry of element substitution due to charge-balancing, and iii) inherited features of olivine before the metal-olivine mixing. While the results obtained are in good agreement with literature values, important differences are observed for Al and Ni concentrations compared with bulk analytical methods. In this work, laser ablation - inductively coupled plasma - mass spectrometry (LA-ICP-MS) was used for the elemental analysis of both pallasite olivine and phosphate phases, including 2D trace element mapping of olivine crystals. Despite their simple mineralogy, relatively limited data are available on their geochemistry and the lateral elemental distribution in individual pallasite olivine crystals. Pallasites are stony‑iron meteorites consisting mainly of olivine and Fe-Ni metal with a formation history that remains widely debated.

Pallasites with rounded olivine indicate that the core–mantle boundary of their planetesimal may not be a simple interface but rather a volume in which interactions between metal, silicate, and other components occur. Lower concentrations of Mn in olivine of the low‐MnO PMG subgroup, and high concentrations of Mn in low‐Al2O3 chromites, trace the development and escape of sulfide‐rich melt in pallasites and the partially chalcophile behavior for Mn in this environment. Farringtonite and phosphoran olivine have not been found in the common subgroup PMG, which are mechanical mixtures of olivine, chromite with moderate Al2O3 contents, primitive solid metal, and evolved liquid metal. These phases form after metal and silicate reservoirs back‐react during decreasing temperature after initial separation, resulting in oxidation of phosphorus and chromium. A reassessment of the literature shows that low‐MnO and high‐FeO subgroups preferentially host rounded olivine and low‐temperature P2O5‐rich phases such as the Mg‐phosphate farringtonite and phosphoran olivine. Here, we review main group pallasite data sets and petrologic characteristics, and present new observations on the low‐MnO pallasite Brahin that contains abundant fragmental olivine, but also rounded and angular olivine and potential evidence of sulfide–phosphide liquid immiscibility. They represent mixtures of core and mantle materials, but the environment of formation is poorly understood, with a quiescent core–mantle boundary, violent core–mantle mixture, or surface mixture all recently suggested. Main group pallasite meteorites are samples of a single early magmatic planetesimal, dominated by metal and olivine but containing accessory chromite, sulfide, phosphide, phosphates, and rare phosphoran olivine.