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The discovery of iron objects in Portugal, dated from the end of the Bronze Age (12th-11th century BC) in the context of habitats, forces us to reconsider the question of their significance. We present the results of a geochemical approach by the comparative analysis of archaeological irons and Portuguese ores. The p-XRF analysis of 15 artifacts from 4 different sites in Beira Interior (Monte do Trigo, Moreirinha and Monte do Frade) and Central (Baiões), indicates that the smelted iron probably derived from two distinct ores. The local typology and the association of the finds with bronze workshops requires a reexamination as to the question of their origin. The chemical characterization of the irons of Beira Interior, indicates that they are of primitive elaboration given their low quality, while that of Baiões already shows a metallurgical evolution which would be understandable if it were more recent. A comparison with other Bronze Age irons underscores their chemical specificity. Local iron rich ores cropping out near Salvador (Penamacor, Beira Interior), were sampled and analyzed by ICP-AES and ICP-MS and compared with various types of iron ores. The composition of Salvador ores compared to that of the Beira Interior artifacts implies a definite consanguinity. The importation of finished objects, such as ingots with local forging must be excluded. The processing of the local ore and its forging by experienced metallurgists but novices in iron metallurgy, is a new and robust explanatory hypothesis in accordance with all the constraints already mentioned. This is the first time that Bronze Age irons can be related to a very likely ore source. The Mediterranean influences, marking the importation of a new and extremely recent know-how, therefore correspond, at least in part, to exchanges from the east and perhaps even to the movement of people. This exotic contribution would be linked to the profound movements in the Mediterranean context of the 12th century, probably from the Mediterranean East with possibly relays in the central Mediterranean. [ABSTRACT FROM AUTHOR]

Matsui et al. (2022) performed X‐ray fluorescence RF analyses of Tutankhamun's dagger and its hilt. Although the approach is indeed interesting, this work has many shortcomings. The absence of reference to standard specimens impairs both absolute values and error estimates, especially in chemical mapping. A Widmanstätten pattern at a scale of 1 mm cannot be revealed by chemical mapping with a step of 0.9 mm and spots exceeding significantly the 1 mm size. The presence of Ca on the hilt is probably an artifact as it can be observed on the blade and other objects as well. Finally, since the hilt and the blade may not be from the same origin, we have no clue about the origin of the dagger blade. [ABSTRACT FROM AUTHOR]

Bronze Age iron artifacts could be derived from either meteoritic (extraterrestrial) or smelted (terrestrial) iron. This unresolved question is the subject of a controversy: are some, all or none made of smelted iron? In the present paper we propose a geochemical approach, which permits us to differentiate terrestrial from extraterrestrial irons. Instead of evaluating the Ni abundance alone (or the Ni to Fe ratio) we consider the relationship between Fe, Co and Ni abundances and their ratios. The study of meteoritic irons, Bronze Age iron artifacts and ancient terrestrial irons permit us to validate this chemical approach. The major interest is that non-invasive p -XRF analyses provide reliable Fe:Co:Ni abundances, without the need to remove a sample; they can be performed in situ, in the museums where the artifacts are preserved. The few iron objects from the Bronze Age sensu stricto that could be analyzed are definitely made of meteoritic iron, suggesting that speculations about precocious smelting during the Bronze Age should be revised. In a Fe:Co:Ni array the trend exhibited by meteoritic irons departs unambiguously from modern irons and iron ores. The trend of Ni/Fe vs Ni/Co in different analysis points of a single object corroded to variable extents provides a robust criterion for identifying the presence of meteoritic iron. It opens the possibility of tracking when and where the first smelting operations happened, the threshold of a new era. It emphasizes the importance of analytical methods for properly studying the evolution of the use of metals and metal working technologies in our past cultures. [ABSTRACT FROM AUTHOR]

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Northwest Africa 3164 is a coarse-grained angrite that shows reaction coronas, a unique character among achondrites. Olivine (Fo57; 1.2 wt% CaO), fassaitic clinopyroxene, anorthite, and spinel account for 46-47, 28-29, 8-13, and 4-8 vol%, respectively; kamacite is an accessory phase. The spinel grains in contact with clinopyroxene are bounded by discontinuous 20 μm thick coronas of anorthite and olivine, indicating the reaction Cpx + Spl → Ol + An (R1). In addition, irregular coronas of clinopyroxene and spinel developed around the primary anorthite in contact with primary olivine, during the reaction Ol + An → Cpx + Spl (R2). R2 also generated clinopyroxene and spinel films between the secondary olivine and anorthite coronas produced during R1, implying that R1 preceded R2. Both are metamorphic reactions that developed in the solid state. Finally, the coronas are cross cut by μm-thick veinlets due to a late shock. A mass-balance study shows that R2 is almost the reverse of R1. The P-T metamorphic evolution of the rock, modeled by calculating a P-T isochemical diagram, indicates an equilibrium T of 940 ± 120 °C at P < 0.9 GPa for the initial assemblage, followed by an increase of T up to approximately 1000-1200 °C during reaction R1 and a subsequent cooling during R2. Several causes are envisaged to account for this metamorphic evolution. Contact metamorphism due to a hot magmatic intrusion in the angrite parent body is favored, as similar metamorphic coronas are well known in metamorphic terrestrial rocks. In addition to differentiation and magmatism, there is now evidence for metamorphism in the angrite parent body, which would have been a large asteroid or a planetary-sized body. [ABSTRACT FROM AUTHOR]

Abstract: The Pathfinder, Spirit and Opportunity missions revealed that Martian soils and rocks are enriched in chlorine (up to 0.6 wt.% Cl). Significant piles of evaporitic sedimentary rocks have also been observed at Meridiani Planum. The SNC meteorites, inferred to come from Mars, hardly ever contain Cl-rich minerals except in secondary alteration products such as clay-rich veinlets and massive halite trapped within olivine from Nakhla. Here we describe the first extra-terrestrial Cl-rich amphibole, in the newly found nakhlite MIL 03346. It is a chloro-potassichastingsite (up to 8% Cl wt.%) that crystallized exclusively as a daughter mineral in some of the melt patches sequestered inside augite phenocryst clusters. It is never found as fracture-filling material nor as discrete grains in the mesostasis. This Cl-rich amphibole crystallized from the evolved residual liquid at some intermediate magmatic stage. This heterogeneous contamination at a magmatic stage provides the first evidence for contamination of a nakhlite parent magma by Cl-rich particles of evaporitic sediments. Such a contamination appears to be very limited to melt patches present in a small number of augite crystals. Because of dilution and devolatilization effects, this contamination remains cryptic in the mesostasis. [Copyright &y& Elsevier]