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Rationale: We have used a high‐precision, high‐efficiency method for the measurement of the ²H/¹H ratios of hydrous silicates (amphiboles) and nominally anhydrous minerals (NAM) such as clinopyroxene, garnet and diamond, which are usually extremely resistant to pyrolysis. This opens up new fields of investigation to better understand the conditions of formation for deep‐Earth minerals. Methods: The technique described here involves Isotope Ratio Mass Spectrometry (IRMS) on‐line in continuous flow mode with an Elemental Analyser (EA) using "purge and trap" technology rather than separation by conventional packed column gas chromatography (GC). The system is equipped with a special high‐temperature furnace reaching 1500°C, with a longer hot zone and improved temperature stability. Emphasis is put on the efficiency of the system to reliably pyrolyse refractory minerals difficult to analyse with other conventional systems. Results: While conventional systems usually fail to generate hydrogen suitable for isotopic analyses, with the technique presented here we were able to measure ²H/¹H ratios from four diamond samples (δ²H = -60, -77, -84 and -79‰ V‐SMOW; average SD = 4.5‰; n = 2), three garnet samples (δ²H from -70 to -63‰), and nine clinopyroxenes (δ²H from -92 to -58‰) associated with seven amphiboles (δ²H from -76 to -27‰) from single mantle rock. Conclusions: The possibility of using such a system to reliably measure ²H/¹H ratios from refractory minerals, which are usually extremely difficult to analyse, offers a new tool of investigation for providing us with unrivaled clues to study the deep interiors of Earth. [ABSTRACT FROM AUTHOR]

In order to determine the incubation temperature of eggs laid by non-avian dinosaurs, we analysed the oxygen isotope compositions of both eggshell carbonate (δ18Oc) and embryo bone phosphate (δ18Op) from seven oviraptorosaur eggs with preserved in ovo embryo bones. These eggs come from the Upper Cretaceous Nanxiong Formation of Jiangxi Province, China. Oviraptorosaur theropods were selected because of their known brooding behaviour as evidenced by preserved adult specimens fossilized in brooding posture on their clutch. Incubation temperature of these embryos was estimated based on the following considerations: eggshell δ18Oc value reflects the oxygen isotope composition of egg water fluid; embryo bones precipitate from the same egg fluid; and oxygen isotope fractionation between phosphate and water is controlled by the egg temperature. A time-dependent model predicting the δ18Op evolution of the embryo skeleton during incubation as a function of egg temperature was built, and measured δ18Oc and δ18Op values used as boundary conditions. According to the model outputs, oviraptorosaurs incubated their eggs within a 35-40°C range, similar to extant birds and compatible with the known active brooding behaviour of these theropod dinosaurs. Provided that both eggshell and embryo bones preserved their original oxygen isotope compositions, this method could be extended to investigate some reproductive traits of other extinct groups of oviparous amniotes. [ABSTRACT FROM AUTHOR]

The oxygen isotope compositions of bones (n = 11) and teeth (n = 20) from 12 Sudanese individuals buried on Sai Island (Nubia) were analysed to investigate the registration of the evolution of the Nile environment from 3700 to 500 years BP and the potential effects of ontogeny on the oxygen isotope ratios. The isotopic compositions were converted into the composition of drinking water, ultimately originating from the Nile. δ18O values decrease during ontogeny; this is mainly related to breastfeeding and physiology. Those of neonates present very large variations. Neonates have a very high bone turnover and are thus able to record seasonal δ18O variations of the Nile waters. These variations followed a pattern very similar to the present one. Nile δ18O values increased from 1.4 to 4.4 ‰ (Vienna Standard Mean Ocean Water) from the Classic Kerma (∼3500 BP) through the Christian period (∼1000 BP), traducing a progressive drying of Northeast Africa. [ABSTRACT FROM AUTHOR]

Rationale In ecological studies, the sulfur isotope compositions (δ34S values) of soft tissues (e.g. hair, skin, nail, muscle, collagen) allow the determination of both past and present-day living environments of organisms. However, technical limitations have so far prevented reliable sulfur isotope analyses of minerals having low sulfur content, such as bioapatite, which is the crystalline component of skeletal tissues. The development of 'purge-and-trap' technology in elemental analysers recently demonstrated new possibilities to solve some of those technical difficulties. Methods We have used a VarioPYROcube elemental analyser (EA) equipped with 'purge-and-trap' technology, interfaced in continuous flow mode to an Isoprime 100 isotope ratio mass spectrometer, to measure the sulfur isotope compositions of bioapatite samples. We first characterised a working calibrated material of chemical composition close to those of our samples, the low-S bearing phosphorite BCR32, against the two δ34SV-CDT reference-calibrated materials, NBS-127 and IAEA-SO-5. We have confirmed a δ34SV-CDT value of +18.4‰ (1 σ = 0.5; n = 18) in agreement with the previously published value. Using BCR32 as a compositional and isotopic reference material, we have then measured the δ34SV-CDT values of various bioapatite tissues (bone, dentine and enamel) from both modern and fossil vertebrates living in different environments (marine, freshwater and terrestrial). Results Our results demonstrate the capacity of this analytical setup to measure the δ34SV-CDT values of low-S bioapatite samples (0.14 to 1.19 wt%) with a good analytical precision (1 σ = 0.5; n = 14). Our results also show that the δ34SV-CDT values of modern and fossil vertebrate bioapatites allow discrimination between marine environments and freshwater or terrestrial ones. Conclusions Sulfur isotope analysis of bioapatite has great potential to track the living environment of extinct vertebrates for which only fossilised bones or teeth have been preserved. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Measurements of sulfur stable isotope ratios (34S/32S) have suffered from technical difficulties in analysing low-S materials reducing their use despite their undeniable scientific interest. The measurement of 34S/32S ratios is a powerful tool for deciphering problems such as determining the sources of environmental pollutants, to detect adulteration, tracking the evolution of the redox state of the oceans and quantifying the role of the bacterial activity in sulfide minerals genesis. We have used a high-precision method of sulfur isotope determination using a new type of elemental analyser based on 'purge and trap' technology. This new technique demonstrates the high quality of 34S/32S measurements for samples with S concentrations lower than 1% m/m. International calibrated references of diverse sulfur-bearing materials were used to calibrate two low (< 1%) S-bearing phosphorites used as compositional reference material for future use as isotopic references: BCR 32 and NBS 120c. δ34 SCDT values of, respectively, 18.2‰ (1 s = 0.3; n = 23) and 18.3‰ (1 s = 0.4; n = 20) are proposed for these. Calibration of both phosphorites with international reference materials led to calculation of a mean standard error close to 0.4‰. The demonstration of a capability to reliably measure S isotope ratios in low-S phosphate minerals or rocks opens up new fields of palaeoenvironmental reconstructions. [ABSTRACT FROM AUTHOR]

The middle Paleolithic stratigraphic sequence of Les Pradelles (Charente, France) spans from the end of Marine Isotope Stage (MIS) 4 until the middle of MIS 3. Micromammal remains are present in all the stratigraphic levels, offering a rare opportunity to address the questions of both environmental and climatic fluctuations throughout this period. Climate modes were studied through the taphonomy, biodiversity and oxygen isotope compositions of phosphate (δ18Op) from 66 samples of rodent tooth enamel. The δ18Op values from the lower sedimentary levels provide summer mean air temperatures of 19±2°C (level 2/1) and of 16±2°C (levels 2A, 2B and 4A). Within the middle of sequence (level 4B), a paleobiodiversity change can be identified with an increase of Dicrostonyx torquatus, which is associated with the largest amplitude in δ18Op values and the highest maximal δ18Op values. At the top of the sequence (level 5-2), a biodiversity change is observed with the increase of Microtus arvalis, but without any change in δ18Op values. The association of cold rodent species with unexpected high and large amplitudes in the δ18Op values of their teeth, possibly indicative of aridity, suggests their deposition during a Heinrich event. [ABSTRACT FROM AUTHOR]

Abstract: Oxygen isotope compositions of phosphate in tooth enamel from large mammals (i.e. horse and red deer) were measured to quantify past mean annual air temperatures and seasonal variations between 145ka and 33ka in eastern France. The method is based on interdependent relationships between the δ18O of apatite phosphate, environmental waters and air temperatures. Horse (Equus caballus germanicus) and red deer (Cervus elaphus) remains have δ18O values that range from 14.2‰ to 17.2‰, indicating mean air temperatures between 7°C and 13°C. Oxygen isotope time series obtained from two of the six horse teeth show a sinusoidal-like signal that could have been forced by temperature variations of seasonal origin. Intra-tooth oxygen isotope variations reveal that at 145ka, winters were colder (−7±2°C) than at present (3±1°C) while summer temperatures were similar. Winter temperatures mark a well-developed West–East thermal gradient in France of about −9°C, much stronger than the −4°C difference recorded presently. Negative winter temperatures were likely responsible for the extent and duration of the snow cover, thus limiting the food resources available for large ungulates with repercussions for Neanderthal predators. [Copyright &y& Elsevier]

Late Devonian aquatic environments hosted the fin-to-limb transition in vertebrates. Upper Devonian (ca. 365-360 Ma) strata in Pennsylvania, USA, preserve a diversity of fishes and tetrapods in coastal marine to fluvial depositional environments, making this region ideal for investigating the ecology and evolution of Late Devonian vertebrates. A key unresolved issue has been reconstructing the specific aquatic habitats that hosted various vertebrates during this period. Specifically, the salinity of environments spanning fresh to shallow marine water is difficult to discern from sedimentological and paleontological analyses alone. Here, we analyze rare earth elements and yttrium (REY) as well as stable oxygen and sulfur isotope compositions (d18O, d34S) in fossil vertebrate bioapatite from late Famennian (ca. 362-360 Ma) strata of the Catskill and Lock Haven formations in the Appalachian Basin, USA, to determine the relative salinity of their aquatic environments. These results confirm the ecological euryhalinity of several taxa (Bothriolepis sp., tristichopterids, and Holoptychius sp.). Our results are the first demonstrating that some early tetrapod species occupied unequivocally freshwater habitats by late Famennian time (ca. 362-360 Ma). Our study shows that integrating sedimentological and paleontological data with combined oxygen and sulfur isotope analysis allows precise tracing of the relative salinity of vertebrate habitats deep in the past. [ABSTRACT FROM AUTHOR]

Two cryptic species of mice coexist on Cyprus: the introduced house mouse and the endemic Cypriot mouse, which remained unnoticed until the beginning of the 21st century. Their trophic positions were investigated using isotopic ecology. The shape and biomechanics of the mandible provided a complementary insight into their respective diets. The Cypriot mouse exhibits generalist habits relying on various natural food resources, including invertebrates, while the house mouse exploits a broad spectrum of anthropic food resources. The Cypriot mouse has a large mandible optimized for chewing at the molars that facilitates consumption of large and hard food items presumably abundant in the natural vegetation of Cyprus. The small mandible size of the house mouse is compensated by a large masseter area and an optimization for incisor biting, making it an all-around tool for foraging on diverse non-natural items. This fine-tuning of generalist feeding behavior ensures efficient niche partitioning between the two species on Cyprus. [ABSTRACT FROM AUTHOR]

Millions of mummified birds serving for religious purpose have been discovered from archeological sites along the Nile Valley of Egypt, in majority ibises. Whether these birds were industrially raised or massively hunted is a matter of heavy debate as it would have a significant impact on the economy related to their supply and cult, and if hunted it would have represented an ecological burden on the birds populations. Here we have measured and analysed the stable oxygen, carbon and radiogenic strontium isotope compositions as well as calcium and barium content of bones along with the stable carbon, nitrogen and sulfur isotope composition of feathers from 20 mummified ibises and birds of prey recovered from various archeological sites of Ancient Egypt. If these migratory birds were locally bred, their stable oxygen, radiogenic strontium and stable sulfur isotopic compositions would be similar to that of coexisting Egyptians, and their stable carbon, nitrogen and oxygen isotope variance would be close, or lower than that of Egyptians. On one hand, isotopic values show that ibises ingested food from the Nile valley but with a higher isotopic scattering than observed for the diet of ancient Egyptians. On the other hand, birds of prey have exotic isotopic values compatible with their migratory behaviour. We therefore propose that most mummified ibises and all the birds of prey analysed here were wild animals hunted for religious practice. [ABSTRACT FROM AUTHOR]

δ2H were measured in water present in tiny primary fluid inclusions trapped in Mesoproterozoic (≈1.4 Ga) and Neoproterozoic (≈0.8 Ga) halite crystals. While the hydrogen concentrations range from 300 to 1500 ppm for the whole sample collection, δ2H values range from −74‰ to −54‰ (VSMOW) for the Mesoproterozoic halite sampled from the Sibley Group, Ontario, Canada, and from −89 to −38‰ for the Neoproterozoic halite from the Browne Formation, Officer Basin, Australia. The amount of evaporation required to precipitate halite is accompanied by a deuterium-enrichment of 30‰ to 90‰. It means that the original aqueous solutions had δ2H values comprised between −140‰ and −90‰. Considering the estimated tropical paleolatitudes for both depositional environments, surface waters were most likely significantly deuterium-depleted relative to modern ones. If such interpretation is partly at variance with the geological record, it could be reconciliated with some modelling outputs of the long-term water cycle. Indeed, several mechanisms produce a progressive deuterium-enrichment of the oceans. Those identified so far are the addition of deuterium-rich extraterrestrial water (cometary dust), the loss of H during water photodissociation by ultraviolet radiation in the upper atmosphere, and the isotopic fractionation that takes place during the hydroxylation of nominally-anhydrous mantle rock-forming minerals. We also propose that the major process able to shift through time the δ2Η of the hydrosphere is the reduction of H 2 O into H 2 during the serpentinization of mantle rocks at mid-ocean ridges. [ABSTRACT FROM AUTHOR]