Looking for Ephesian workshops: an integrated petrographic, geochemical, and chrono-typological approach to Late Hellenistic Ephesos lamps

In this pilot study, Late Hellenistic mold-made lamps from Ephesos are investigated by combining chrono-morphological and stylistic features with thin-section petrography and neutron activation analysis. Coeval wares of Ephesian production and clay samples collected around the site as well as published data from the Bonn database are considered local reference material. The results point to a network of local/regional workshops sharing facilities and/or a labor force dedicated to distinct tasks. The whole evidence is consistent with the very beginning of a nucleated workshop industry able to optimize the productivity of mold-made wares and fill the demand of an increased regional and supra-regional market. The typological and compositional variability of the latest phases could suggest a gradual transfer of potting activities towards areas providing better-suited clay sources.

Role of sediment in generating contemporaneous, diverse “type” granitoid magmas

Granite typology categorizes granitoid rocks based upon distinguishing characteristics that are interpreted to indicate sources, conditions of generation, and, by implication, tectonic setting. Complexities of elemental and isotopic geochemistry, however, commonly preclude simple typological interpretation and suggest more complex petrogenetic histories. Granitoids from the Songpan-Ganzi terrane in the eastern Tibetan Plateau were emplaced within a short interval (~15 m.y.). They display mineralogical and geochemical characteristics that are consistent with a wide range of proposed typologies (I-, S-, and A-type; high Ba-Sr and adakitic variants). Despite their close spatial and temporal association, these granitoids exhibit diversity in geochemical characteristics that indicates a broad spectrum of contributing sources. Radiogenic isotope data reveal a continuum from primitive to evolved crustal compositions; i.e., 87Sr/86Sr(t) = 0.704–0.715 and εNd(t) = +2 to –11. All granitoid “types” have variable but commonly high zircon δ18O (+4.1‰ to +11.6‰) and low whole-rock Li-B-Mg isotopic ratios compared to mantle and/or seawater (δ7Li = +5.1‰ to –3.2‰; δ11B = –10.7‰ to –16.5‰; δ26Mg = –0.23‰ to –0.59‰). These stable isotopic compositions suggest that the Songpan-Ganzi granitic magmas of all “types” had contributions from sediment, ranging from minor to dominant. The highly variable isotopic compositions of the granitoids rule out a single homogeneous source for these diverse yet contemporaneous granitoids. Their compositional variability may have been significantly influenced by sedimentary contributions, and these results demonstrate the difficulty of straightforward assignment and interpretation of granitoids using conventional typology.

Temporal variability in quantitative human gut microbiome profiles and implications for clinical research

While clinical gut microbiota research is ever-expanding, extending reference knowledge of healthy between- and within-subject gut microbiota variation and its drivers remains essential; in particular, temporal variability is under-explored, and a comparison with cross-sectional variation is missing. Here, we perform daily quantitative microbiome profiling on 713 fecal samples from 20 Belgian women over six weeks, combined with extensive anthropometric measurements, blood panels, dietary data, and stool characteristics. We show substantial temporal variation for most major gut genera; we find that for 78% of microbial genera, day-to-day absolute abundance variation is substantially larger within than between individuals, with up to 100-fold shifts over the study period. Diversity, and especially evenness indicators also fluctuate substantially. Relative abundance profiles show similar but less pronounced temporal variation. Stool moisture, and to a lesser extent diet, are the only significant host covariates of temporal microbiota variation, while menstrual cycle parameters did not show significant effects. We find that the dysbiotic Bact2 enterotype shows increased between- and within-subject compositional variability. Our results suggest that to increase diagnostic as well as target discovery power, studies could adopt a repeated measurement design and/or focus analysis on community-wide microbiome descriptors and indices.

Geochemical variability as an indicator for large volume eruptions in volcanic arcs

Caldera-forming eruptions have the potential to impact global climate and induce drastic socioeconomic change. However, the criteria to identify volcanoes capable of producing large magnitude eruptions in the future are not well constrained. Here we compile and analyse data, revealing that volcanoes which have produced catastrophic caldera-forming eruptions in the past, typically show larger ranges of long-term erupted bulk-rock geochemistry compared to those that have not. This observation suggests that geochemical variability is a measure of a magmatic systems size. Using a 2D thermal model that simulates the growth and evolution of crustal-scale magmatic systems by stochastic injection of dikes and sills, we show that such behaviour is consistent with differences in crustal magma fluxes. Higher injection rates accumulate greater melt volumes in more extensive crustal plumbing systems, leading to more variable distributions of temperatures and thus melt composition. We conclude that compositional variability should be included in the catalogue of criteria to identify volcanic systems with greater probabilities of producing future large eruptions. Importantly, this allows to identify stratovolcanoes with caldera-like geochemical signatures, which have not yet been recognized as systems with greater probabilities of producing large magnitude eruptions.

Gypsum Precipitating From Volcanic Effluent as an Archive of Volcanic Activity

Records of volcanic activity are a key resource in volcano monitoring and hazard mitigation. The time period for which such records are available and the level of detail vary widely among volcanic centers and there is, therefore, a need for supplementary sources of this information. Here, we use growth-zoned gypsum as a mineral archive of the activity of Kawah Ijen volcano in East-Java, Indonesia. Gypsum precipitates where water seeps from the crater lake and hydrothermal system, and it has formed a 100 m long cascading plateau. A 19 cm plateau cross-section was analysed for minor and trace elements using laser-ablation ICP-MS. Absolute ages were assigned to this transect based on 210Pb dating. This 210Pb age model was corrected for variations in the 210Pb0 resulting from fluctuations in the volcanic radon flux by using 84Kr/36Ar and 132Xe/36Ar. The age model indicates that the transect covers a period from 1919 ± 12 to 2008 ± 0.2. Gypsum-fluid partition coefficients (D) permit the gypsum compositions to be converted to the concentrations in the fluid from which each growth zone grew. The D-values also show the compatibility of the elements in the gypsum structure, and identify the LREE, Sr, Pb, Tl, Ni, Co, Cu, Zn, Cd, Sb, Th, and Mo as least susceptible to contamination from rock fragment and mineral inclusions, and therefore as most reliable elements of the gypsum record. Compositional variability in the timeseries correlates with known element behavior in the Kawah Ijen system and shows three element groups: the LREE, Sr, and Pb that represent rock-leaching; Cu, Zn, and Cd, which have previously been linked to immiscible sulfide destabilization in a deep-seated basalt; and Sb, Tl, and As which point to a contribution from the shallow system and evolved magma. Moreover, the gypsum record shows that episodes of unrest and quiescence have a distinct compositional signature in Kawah Ijen seepage fluids, and can be distinguished. Thus, we show that gypsum is a sensitive recorder of volcanic activity and can provide detailed information on the state of the magmatic-hydrothermal system in the past.

A Crystal Mush Perspective Explains Magma Variability at La Fossa Volcano (Vulcano, Italy)

The eruptive products of the last 1000 years at La Fossa volcano on the island of Vulcano (Italy) are characterized by abrupt changes of chemical composition that span from latite to rhyolite. The wide variety of textural features of these products has given rise to several petrological models dealing with the mingling/mixing processes involving mafic-intermediate and rhyolitic magmas. In this paper, we use published whole-rock data for the erupted products of La Fossa and combine them in geochemical and thermodynamic modelling in order to provide new constrains for the interpretations of the dynamics of the active magmatic system. The obtained results allow us to picture a polybaric plumbing system characterized by multiple magma reservoirs and related crystal mushes, formed from time to time during the differentiation of shoshonitic magmas, to produce latites, trachytes and rhyolites. The residing crystal mushes are periodically perturbated by new, fresh magma injections that, on one hand, induce the partial melting of the mush and, on the other hand, favor the extraction of highly differentiated interstitial melts. The subsequent mixing and mingling of mush-derived melts ultimately determine the formation of magmas erupted at La Fossa, whose textural and chemical features are otherwise not explained by simple assimilation and fractional crystallization models. In such a system, the compositional variability of the erupted products reflects the complexity of the physical and chemical interactions among recharging magmas and the crystal mushes.

Obtaining and determining antioxidant activity of polyphenolic extracts obtained from propolis

Over the years, time has given us a whole series of novelties in the fi eld of natural medicine, which have managed to truly prove their value and keep up to date. Th e application of apitherapy has been known since ancient times and today the interest in this branch of natural medicine is growing worldwide. Among bee products, with an indisputable value is also propolis, which is currently widely studied, and as a result is the subject of multiple therapeutic uses based on evidence. Research in the fi eld of propolis preparations has expanded considerably and is of major medical and pharmaceutical interest. Propolis is an excellent anti-infl ammatory, healing and epithelializing, hepatoprotective, immuno-biostimulator, capillary tonic and tissue regenerator. It is remarkable that, due to its complexity and compositional variability, propolis retains its full antimicrobial capacity, unlike synthetic antibiotics, which bacteria develop resistance over time, requiring the periodic introduction of new antibiotics. Th e study on obtaining and analyzing propolis extracts, by determining the total polyphenolic and antioxidant activity, by scavenging method of the free radical DPPH, is an important premise for the use and development of new pharmaceutical forms containing propolis for multiple curative-prophylactic uses based on local raw materials.

Capturing the structural and compositional variability of Opalinus Clay: constraints from multidisciplinary investigations of Mont Terri drill cores (Switzerland)

Opalinus Clay is considered a potential host rock for radioactive waste disposal. The Jurassic claystone formation is composed of several facies and subfacies types, which are characterized by varying amounts of quartz, carbonates (cements and fossils) and clay minerals. To provide samples for ongoing experimental and numerical studies, a complete core section was drilled in the Mont Terri rock laboratory. The lithological and structural variability (including tectonic fault structures) from borehole BAD-2 was investigated using a multidisciplinary approach including high-resolution geoelectric in situ borehole measurements, mineralogical/geochemical and (micro)structural analyses.The lithological–compositional variability was captured by successfully applying a modified subfacies approach, which is independently confirmed by the geochemical data and ERT (Electrical Resistivity Tomography) measurements. The variability on the cm to dm scale perpendicular to bedding can be determined based on the mean resistivity and variation of amplitude. In particular, the facies transitions could be precisely located. The new results suggest that both shaly facies types form the homogenous part of the investigated section, whereas the sandy facies and especially the carbonate-rich sandy facies represent the more heterogeneous lithofacies types of the Opalinus Clay. The varying resistivity can be attributed to differences in clay mineral and carbonate content. Regarding the structural variability, brittle faults were observed with varying frequency throughout the investigated section. Most fault planes occur in the shaly facies types, some of them concentrate along heterogeneities on the subfacies scale. The striking reproducibility of the measurements and observations was confirmed by a comparison with boreholes drilled in parallel, indicating a rather low compositional–structural variability parallel to bedding. The applied multidisciplinary approach is well suited to depict the vertical and lateral variability of a claystone formation, allowing an assessment of the degree of homogeneity/heterogeneity based on the subfacies concept.