Timothy R. Rose

Detection of structurally bound hydroxyl in fluorapatite from Apollo Mare basalt 15058,128 using TOF-SIMS

Abstract Fluorapatite grains from Apollo 15 Mare basalt 15058,128 were analyzed by Raman spectroscopy, Raman spectral imaging, time-of-flight secondary ion mass spectrometry (TOF-SIMS), field emission scanning electron microscopy (FE-SEM), and electron probe microanalysis (EPMA) in an attempt to detect structurally bound OH- in the fluorapatite. Although OH- could not be definitively detected by Raman spectroscopy because of REE-induced photoluminescence, hydroxyl was detected in the fluorapatite by TOF-SIMS. The TOF-SIMS technique is qualitative but capable of detecting the presence of hydroxyl even at trace levels. Electron microprobe data indicate that on average, F and Cl (F+Cl) fill the monovalent anion site in these fluorapatite grains within the uncertainties of the analyses (about 0.07 ± 0.01 atoms per formula unit). However, some individual spot analyses have F+Cl deficiencies greater than analytical uncertainties that could represent structural OH-. On the basis of EPMA data, the fluorapatite grain with the largest F + Cl deficiency constrains the upper limit of the OH- content to be no more than 4600 ± 2000 ppm by weight (the equivalent of ~2400 ± 1100 ppm water). The TOF-SIMS detection of OH- in fluorapatite from Apollo sample 15058,128 represents the first direct confirmation of structurally bound hydroxyl in a lunar magmatic mineral. This result provides justification for attributing at least some of the missing structural component in the monovalent anion site of other lunar fluorapatite grains to the presence of OH-. Moreover, this finding supports the presence of dissolved water in lunar magmas and the presence of at least some water within the lunar interior.

Hemoglobin-derived porphyrins preserved in a Middle Eocene blood-engorged mosquito

Significance Fossils, in addition to documenting the existence of extinct species, can often provide information on the behavior of ancient organisms. The present study describes the fossil of a blood-engorged mosquito in oil shale from northwestern Montana. The existence of this rare specimen extends the existence of blood-feeding behavior in this family of insects 46 million years into the past. Heme, the oxygen-carrying group of hemoglobin in the host’s blood, was identified in the abdomen of the fossil mosquito by nondestructive mass-spectrometry analysis. Although large and fragile molecules such as DNA cannot survive fossilization, other complex organic molecules, in this case iron-stabilized heme, can survive intact and provide information relative to the mechanisms of the fossilization process. Although hematophagy is found in ∼14,000 species of extant insects, the fossil record of blood-feeding insects is extremely poor and largely confined to specimens identified as hematophagic based on their taxonomic affinities with extant hematophagic insects; direct evidence of hematophagy is limited to four insect fossils in which trypanosomes and the malarial protozoan Plasmodium have been found. Here, we describe a blood-engorged mosquito from the Middle Eocene Kishenehn Formation in Montana. This unique specimen provided the opportunity to ask whether or not hemoglobin, or biomolecules derived from hemoglobin, were preserved in the fossilized blood meal. The abdomen of the fossil mosquito was shown to contain very high levels of iron, and mass spectrometry data provided a convincing identification of porphyrin molecules derived from the oxygen-carrying heme moiety of hemoglobin. These data confirm the existence of taphonomic conditions conducive to the preservation of biomolecules through deep time and support previous reports of the existence of heme-derived porphyrins in terrestrial fossils.

Kulanaokuaiki Tephra (ca, A.D. 400-1000): Newly recognized evidence for highly explosive eruptions at Kilauea Volcano, Hawai'i

Kīlauea may be one of the world9s most intensively monitored volcanoes, but its eruptive history over the past several thousand years remains rather poorly known. Our study has revealed the vestiges of thin basaltic tephra deposits, overlooked by previous workers, that originally blanketed wide, near-summit areas and extended more than 17 km to the south coast of Hawai‘i. These deposits, correlative with parts of tephra units at the summit and at sites farther north and northwest, show that Kīlauea, commonly regarded as a gentle volcano, was the site of energetic pyroclastic eruptions and indicate the volcano is significantly more hazardous than previously realized. Seventeen new calibrated accelerator mass spectrometry (AMS) radiocarbon ages suggest these deposits, here named the Kulanaokuaiki Tephra, were emplaced ca. A.D. 400–1000, a time of no previously known pyroclastic activity at the volcano. Tephra correlations are based chiefly on a marker unit that contains unusually high values of TiO 2 and K 2 O and on paleomagnetic signatures of associated lava flows, which show that the Kulanaokuaiki deposits are the time-stratigraphic equivalent of the upper part of a newly exhumed section of the Uwēkahuna Ash in the volcano9s northwest caldera wall. This section, thought to have been permanently buried by rockfalls in 1983, is thicker and more complete than the previously accepted type Uwēkahuna at the base of the caldera wall. Collectively, these findings justify the elevation of the Uwēkahuna Ash to formation status; the newly recognized Kulanaokuaiki Tephra to the south, the chief focus of this study, is defined as a member of the Uwēkahuna Ash. The Kulanaokuaiki Tephra is the product of energetic pyroclastic falls; no surge- or pyroclastic-flow deposits were identified with certainty, despite recent interpretations that Uwēkahuna surges extended 10–20 km from Kīlauea9s summit.

The evolutionary convergence of mid-Mesozoic lacewings and Cenozoic butterflies

Mid-Mesozoic kalligrammatid lacewings (Neuroptera) entered the fossil record 165 million years ago (Ma) and disappeared 45 Ma later. Extant papilionoid butterflies (Lepidoptera) probably originated 80–70 Ma, long after kalligrammatids became extinct. Although poor preservation of kalligrammatid fossils previously prevented their detailed morphological and ecological characterization, we examine new, well-preserved, kalligrammatid fossils from Middle Jurassic and Early Cretaceous sites in northeastern China to unravel a surprising array of similar morphological and ecological features in these two, unrelated clades. We used polarized light and epifluorescence photography, SEM imaging, energy dispersive spectrometry and time-of-flight secondary ion mass spectrometry to examine kalligrammatid fossils and their environment. We mapped the evolution of specific traits onto a kalligrammatid phylogeny and discovered that these extinct lacewings convergently evolved wing eyespots that possibly contained melanin, and wing scales, elongate tubular proboscides, similar feeding styles, and seed–plant associations, similar to butterflies. Long-proboscid kalligrammatid lacewings lived in ecosystems with gymnosperm–insect relationships and likely accessed bennettitalean pollination drops and pollen. This system later was replaced by mid-Cretaceous angiosperms and their insect pollinators.

Using cathodoluminescence spectroscopy of cretaceous calcareous microfossils to distinguish biogenic from early-diagenetic calcite.

A comparative cathodoluminescence (CL) spectroscopic study of extraordinarily well-preserved versus diagenetically altered Turonian (∼92 Ma before present) calcitic and aragonitic microfossils was performed to document the cathodoluminescence characteristics of two common Cretaceous carbonate producers, foraminifera and calcareous dinoflagellates. Unaltered specimens reveal a conspicuous peak in the blue CL band at ≈ 400 nm that has rarely been previously reported for biogenic carbonates. We interpret this luminescence as an indicative feature of the primary bio-mineralized shells of calcareous dinoflagellates and foraminifera. Orange luminescence as the second important CL emission band (≈ 620 nm) in calcite generally increases with diagenetic cement overgrowth and recrystallization but can also be present in unaltered material. Thus, orange CL of biogenic calcite is not an unequivocal diagenetic indicator. Accordingly, spectroscopic investigation of both the ≈ 400 and ≈ 620 nm peaks represents a more objective criterion to evaluate the degree of diagenetic alteration. The ratio of relative intensities of the blue CL versus orange CL can provide a semiquantitative measure with relative intensity ratios blue:orange >2 occurring in the least diagenetically altered microfossils. Comparison of unaltered specimens of separate species reveals elemental differences that potentially indicate species-specific biomineralization or habitats.

Cathodoluminescence of natural, plastically deformed pink diamonds.

The 49 type I natural pink diamonds examined exhibit color restricted to lamellae or bands oriented along {111} that are created by plastic deformation. Pink diamonds fall into two groups: (1) diamonds from Argyle in Australia and Santa Elena in Venezuela are heavily strained throughout and exhibit pink bands alternating with colorless areas, and (2) diamonds from other localities have strain localized near the discrete pink lamellae. Growth zones are highlighted by a blue cathodoluminescence (CL) and crosscut by the pink lamellae that emit yellowish-green CL that originates from the H3 center. This center probably forms by the recombination of nitrogen-related centers (A-aggregates) and vacancies mobilized by natural annealing in the Earths mantle. Twinning is the most likely mechanism through which plastic deformation is accommodated for the two groups of diamonds. The plastic deformation creates new centers visible through spectroscopic methods, including the one responsible for the pink color, which remains unidentified. The differences in the plastic deformation features, and resulting CL properties, for the two groups might correlate to the particular geologic conditions under which the diamonds formed; those from Argyle and Santa Elena are deposits located within Proterozoic cratons, whereas most diamonds originate from Archean cratons.

Smithsonian Microbeam Standards: Not Just Our Father’s Microprobe Standards

Thanks to the classical gravimetric analytical work of Eugene Jarosewich and his coworkers in the Department of Mineral Sciences of the Smithsonian Institution, laboratories all over the world are using natural and synthetic minerals and glasses for the calibration of electron microprobes. Many of the Smithsonian microbeam standards (SMS), being natural materials, are impure. Gene cautioned us about impurities in the original materials and gave examples of the few that were known at the time [1,2]. Currently, impurities in the SMS are being characterized in composition, size and abundance in order to improve the value of these materials as analytical standards. In an effort to increase the usefulness of these widely distributed materials, cathodoluminescence (CL) spectra have been collected from ten of these. In addition, the SMS are being used as the core materials for a library of energy dispersive x-ray spectra of minerals and glasses. A polished mount containing grains of twenty-nine of the SMS has been closely examined using a field emission scanning electron microscope. Of these, impurities have been found in twelve. Most of the impurities can be easily observed in backscattered electron images. Compositions of these have been determined by energy dispersive x-ray spectrometry (EDS) and their abundances have been visually estimated. Rockport fayalite (USNM 85276) is particularly problematic as ~10% of the grains are of a higher silica phase, possibly the amphibole grunerite, a known accessory phase in the Rockport fayalite assemblage (see figure 1). The accessory phase also occurs as inclusions in the fayalite. Table 1 lists impurities identified in the standard materials in this preliminary investigation. This listing serves as the beginning of a catalog of these impurities. Many microprobe and SEM users are familiar with the strong blue CL of the SMS benitoite (USNM 86539, see figure 2A). CL can be a powerful tool in the characterization of geologic materials. Preliminary work has found CL in ten of the SMS mineral standards. Spectral features range from sharp to broad peaks from ultraviolet to infrared wavelengths. The CL spectrum of corundum (USNM 6578) is shown in figure 2B. Table 2 lists selected minerals and preliminary observations of their CL spectral features. Refinement of precise peak positions through improved resolution as well as deconvolution of complex overlapping peaks is underway. It is hoped that the identification of these peaks will become useful as inter-laboratory calibration standards similar to the way these materials have been used as compositional standards for microprobe analysis. A library of energy dispersive x-ray spectra of minerals and glasses is being created using the minerals in the SMS. Spectra of additional minerals, largely from the Smithsonian collections, are being added to the EDS library. It is intended that this library will continue to grow. The CL and EDS spectra, as well as the catalog of inclusions, are available on the Department of Mineral Sciences website. These data will be updated as new information about these materials becomes known. Contributions to the catalog of impurities in the standards are welcome. The above information about the SMS, including reference literature and how to request them can be found at: http://mineralsciences.si.edu/

Hyperspectral X-ray Analysis of Submicrometer-scale Heterogeneities in a Venerable Compositional Standard Provided by Nature: Kakanui Hornblende

Among the most prominent features of the Kakanui breccia found on the south island of New Zealand are large hornblende xenocrysts (foreign crystals), some reaching more than a decimeter in length [1]. Because the atomic structure of hornblende is sufficiently complex, a wide range of cations can be readily accommodated into multiple crystallographic sites. Kakanui hornblende is more specifically kaersutite, a Tiand Ca-rich amphibole whose ideal formula may be written: Ca2(Na,K)(Mg,Fe ,Fe)4Ti(Si6Al2)O22(OH,F)2 [2] The large crystal size, together with Kakanui hornblende’s “cation soup,” made it an ideal candidate for one of the first reference specimens characterized by Gene Jarosewich during his early years of research at the Smithsonian Institution [3,4]. This material has proven to be of great value to many by virtue of its use as a chemical standard in hundreds of published geological studies. Gene’s careful wet chemical analyses, coupled with his EPMA homogeneity studies, provided the Earth and planetary science community with the best and largest set of like-standards for X-ray microanalysis of minerals and natural glasses. We have conducted a modern reexamination of Kakanui hornblende and have discovered fine-scale chemical heterogeneity invisible to Jarosewich and co-workers when they published their often cited Geostandards Newsletter paper in 1980.

Status of the Smithsonian Microbeam Standards 2017 With a Discussion of the Venerable VG-2 Basalt Glass

In 1980, the compositions of a set of microbeam reference materials were published [1] and made available to the world. These mostly mineral and natural glasses were characterized by classical wetchemical analysis by staff of the Department of Mineral Sciences of the Smithsonian Institution (SI) and named the Smithsonian Microbeam Standards (SMS). Additional carbonates, synthetic rare-earth element phosphates and trace element doped synthetic glasses were added to the collection bringing the total number of currently available samples to 57. To date more than 1300 requests have been filled with over 20,000 individual samples distributed to laboratories worldwide free of charge. Whereas a few of these are no longer available because of very limited quantity, most have quantities sufficient for distribution for many decades at the current demand in aliquots of sufficient size for electron beam microanalysis reference mounts. However, in the last ten years there has been about a threefold increase in the number of SMS distributed (see figure 1). The reason for this increase is not clear. Many requests are for labs with new instrumentation including more frequently for quantification using energy dispersive x-ray spectroscopy. More requests are also coming from laser ablation labs for which only some of the SMS are in sufficient quantity to be appropriate. Laboratories with heavily used mounts in need of replacement are encouraged to request replacement samples. The Corning glass archaeological reference samples, doped with selected trace elements, exist in reasonably large enough quantities to be suitable for destructive analytical methods.