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Fine earthenwares imported from England are a distinctive artifact type frequently found on early nineteenth century Native American and Euro-American sites in eastern North America. Relatively rapid changes in decorative motifs and technologies can easily be identified by eye and provide information about site chronology and economic status. However, visual analyses of sherds usually can provide only general information because most assemblages are very fragmented. We present the chemical composition of pigments and glazes from sherds from two sites occupied during the first half of the nineteenth century: Pokagon Village, a Native American site (southwestern Michigan); and Collier Lodge, a Euro-American site (northwestern Indiana). Multi-element compositions of glazed portions of 12 sherds (with 3 different decorations, 2 specimens from each site of each pattern) were determined by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), micro X-ray fluorescence (μXRF), and laser-ablation-inductively coupled mass spectrometry (LA-ICP-MS). SEM-EDS was especially useful for determining glaze composition, μXRF rapidly provides information on pigment composition and Pb content, and LA-MC-ICP-MS provides information on trace elements and Pb isotopes that reflect different raw material sources.

Pallasite meteorites, which consist primarily of olivine and metal, may be remnants of disrupted core-mantle boundaries of differentiated asteroids or planetesimals. The early thermal histories of pallasites are potentially recorded by minor- and trace-element zonation in olivine. However, constraining this history requires knowledge of element behavior under the conditions of pallasite formation, which is lacking for many of the main elements of interest (e.g., Co, Cr, Mn). In this study, we experimentally determined metal/olivine partition coefficients for Fe, Ni, Co, Cr, and Mn in a pallasite analogue at subsolidus temperatures. Metal/olivine partition coefficients (KM ) increase in the order KMn < KCr < 1 < KFe < KCo < KNi , with five orders of magnitude separating KMn from KNi . Transition metals also become more siderophile with increasing experimental temperature (900 to 1550°C). The experiments incidentally produced diffusion profiles in olivine for these elements; Our results suggest they diffuse through olivine at similar rates. Core compositions of pallasite olivines are consistent with high-temperature equilibration with FeNi-metal. Olivine zonation toward crystal rims varies significantly for the investigated transition metals. We suggest rim zonation results from partial re-equilibration during late stage crystallization of minor phases (e.g., chromite, phosphates). This re- equilibration occurred over short timescales relative to overall pallasite cooling, likely tied to initial cooling rates on the order of 100-300°C/Myr.

This study reports a comprehensive cross-sectional analysis of major and trace element abundances and 240Pu/239Pu ratios within vertically oriented Trinitite thin sections. The upper glassy layer (~2 mm thick) represents fused desert sand combined with devolatilized fallout from the debris cloud. The vertical distribution of 240Pu/239Pu ratios indicates that residual fuel was incorporated deeper (up to ~10 mm depth) into Trinitite than previously reported. This requires thorough mixing and disturbance of the upper cm of the blast site prior to or during the initial melting of the desert sand resulting from the nuclear explosion.

Quantitative textural analysis is a powerful tool in the investigation of basalt crystallization. We present the first comprehensive crystal size distribution analysis of Apollo 17 high-titanium lunar basalts, with a focus on ilmenite. Crystal size distributions of ilmenite, pyroxene, plagioclase, olivine and armalcolite were determined for 18 high-Ti mare basalt samples from the Apollo 17 mission. A subset of the ilmenite size distribution (size bins of

Apollo 14 (A-14) impact melt olivine vitrophyres (OVs), composed of olivine phenocrysts in an opaque glass matrix with minor amounts of pyroxene and plagioclase, are petrographically similar to pristine quenched A-14 high-alumina (high-Al) and Apollo 12 (A-12) basalts. Textural and chemical analyses have been conducted on olivines within impact melt and pristine mare basalt clasts from A-14 breccia 14321 as well as various olivine-phyric Apollo 12 and 17 basalts to be able to distinguish between the petrographically similar samples. The A-14 high-Al basalts examined here represent samples from each of the three chemical groups (A, B, C). Examples from the three A-12 basalt suites (Ilmenite, Olivine, Pigeonite) and olivine-rich Apollo 17 (A-17) Type C basalt, 74275, have also been analyzed. As a complement to the chemical analyses, crystal size distributions (CSDs) were determined for approximately half of the samples investigated here (due to a small number of olivine crystals that did not produce statistically meaningful CSDs on half of the samples), and confirm that although similar, the basalts and impact melts are texturally distinct. Olivines from A-14 impact melts have the highest average forsterite contents (average Fo ∼0.82) and generally the lowest average Co (37 ppm) and Mn (1544 ppm) abundances, thus chemically distinguishing them from the pristine basalts. In addition, chemical compositions obtained for olivine from 14321,1486 are most likely representative of an impact melt and thus contradict its previous classification as a high-Al basalt ( Neal et al., 1988 ); olivine from, 1486 have similar average forsterite (average Fo ∼0.82) and Ti/V-ratio to the OVs. Furthermore, on the basis of their chemical compositions, olivines have been identified within the impact melts that are likely inherited from basalts; these olivines are chemically distinct from the rest of the impact melt olivine population with lower forsterite (0.67–0.80) and low Ti/V (∼10), which are similar to olivine compositions from the A-14 high-Al basalts. In addition to distinguishing between sample types from A-14, olivine compositions can also be used to distinguish between pristine mare basalts from various missions. Olivine within the selected samples from the individual A-12 basalt suites can also be distinguished chemically from one another using the Ti/V ratio, where Olivine suite basalts have Ti/V 3.5. The results indicate that combined use of CSDs and chemical analyses of olivine can be used to reliably distinguish between (1) impact melts and pristine Apollo 14 basalts, (2) basalts from different landing sites, and (3) individual basalt suites from a single site.

Seven ilmenite (FeTiO3) megacrysts derived from alnoite pipes (Island of Malaita, Solomon Islands) were characterised for their major and trace element compositions in relation to their potential use as secondary reference materials for in situ microanalysis. Abundances of thirteen trace elements obtained by laser ablation ICP-MS analyses (using the NIST SRM 610 glass reference material) were compared with those determined by solution-mode ICP-MS measurements, and these indicated good agreement for most elements. The accuracy of the LA-ICP-MS protocol employed here was also assessed by repeated analysis of MPI-DING international glass reference materials ML3B-G and KL2-G. Several of the Malaitan ilmenite megacrysts exhibited discrepancies between laser ablation and solution-mode ICP-MS analyses, primarily attributed to the presence of a titano-magnetite exsolution phase (at the grain boundaries), which were incorporated solely in the solution-mode runs. Element abundances obtained by LA-ICP-MS for three of the ilmenite megacrysts (CRN63E, CRN63H and CRN63K) investigated here had RSD (2s) values of

The first nuclear bomb detonation on Earth involved a plutonium implosion-type device exploded at the Trinity test site (33°40′38.28″N, 106°28′31.44″W), White Sands Proving Grounds, near Alamogordo, New Mexico. Melting and subsequent quenching of the local arkosic sand produced glassy material, designated “Trinitite”. In cross section, Trinitite comprises a thin (1–2 mm), primarily glassy surface above a lower zone (1–2 cm) of mixed melt and mineral fragments from the precursor sand. Multiple hypotheses have been put forward to explain these well-documented but heterogeneous textures. This study reports the first quantitative textural analysis of vesicles in Trinitite to constrain their physical and thermal history. Vesicle morphology and size distributions confirm the upper, glassy surface records a distinct processing history from the lower region, that is useful in determining the original sample surface orientation. Specifically, the glassy layer has lower vesicle density, with larger sizes and more rounded population in cross-section. This vertical stratigraphy is attributed to a two-stage evolution of Trinitite glass from quench cooling of the upper layer followed by prolonged heating of the subsurface. Defining the physical regime of post-melting processes constrains the potential for surface mixing and vesicle formation in a post-detonation environment.