Selected hybrids of the wine grape variety Seibel 5279

In the resistance breeding programme of our Institute, which was begun after World War II, the French resistant hybrids Seyve Villard and Seibel, both of which resulted from crosses involving American species, were used for resistance sources. In the resistance breeding programme at Kecskemet, the variety Seibel 5279 was used first as a male parent to transfer resistance. From the resulting hybrid families the variety candidates RF 5 (Reflex), RF 16 (Refren) and RF 48 (Reform) were selected because of their valuable characters. Data collected over several years demonstrate the value of these selections from both a breeding and production point of view. This generation represents the first step in the breeding programme and the results encourage us to continue our work

A database of noble gases in lunar samples in preparation for mass spectrometry on the Moon

The lunar regolith provides a temporal archive of the evolution of the Moon and inner Solar System over the last ~4 billion years. During this time, noble gases have been trapped and produced within soils and rocks at the lunar surface. These noble gas concentrations can be used to unravel the history of lunar material and shed light on processes that have evolved the surface of the Moon through time. We have collected published noble gas data for a range of lunar samples including soils, regolith breccias, crystalline (e.g., mare basalts, anorthosite) and impact-melt rocks. The compilation includes noble gas concentrations and isotope ratios for He, Ne, Ar, Kr and Xe; trapped, cosmogenic and radiogenic isotopes; and cosmic ray exposure ages. We summarise the significance of these data, which can be used as a baseline for expected noble gas concentrations in a range of lunar samples, and provide a framework for future in situ noble gas measurements on the lunar surface

An ancient reservoir of volatiles in the Moon sampled by lunar meteorite Northwest Africa 10989

Northwest Africa (NWA) 10989 is a recently found lunar meteorite we used to elucidate the history of volatiles (H and Cl) in the Moon through analysis of its phosphates. The petrology, bulk geochemistry and mineralogy of NWA 10989 are consistent with it being a lunar meteorite with intermediate-iron bulk composition, composed of 40% of mare basaltic material and ~ 60% non-mare material, but with no obvious KREEP-rich basaltic components. It is probable that the source region for this meteorite resides near a mare–highlands boundary, possibly on the farside of the Moon. Analyses of chlorine and hydrogen abundances and isotopic composition in apatite and merrillite grains from NWA 10989 indicate sampling of at least two distinct reservoirs of volatiles, one being similar to those for known mare basalts from the Apollo collections, while the other potentially represents a yet unrecognized reservoir. In situ Th-U-Pb dating of phosphates reveal two distinct age clusters with one ranging from 3.98 ± 0.04 to 4.20 ± 0.02 Ga, similar to the ages of cryptomare material, and the other ranging from 3.32 ± 0.01 to 3.96 ± 0.03 Ga, closer to the ages of mare basalts known from the Apollo collections. This lunar breccia features mixing of material, among which a basaltic D-poor volatile reservoir which doesn’t appear to have been recorded by Apollo samples

On the origin and evolution of the material in 67P/Churyumov-Gerasimenko

International audiencePrimitive objects like comets hold important information on the material that formed our solar system. Several comets have been visited by spacecraft and many more have been observed through Earth- and space-based telescopes. Still our understanding remains limited. Molecular abundances in comets have been shown to be similar to interstellar ices and thus indicate that common processes and conditions were involved in their formation. The samples returned by the Stardust mission to comet Wild 2 showed that the bulk refractory material was processed by high temperatures in the vicinity of the early sun. The recent Rosetta mission acquired a wealth of new data on the composition of comet 67P/Churyumov-Gerasimenko (hereafter 67P/C-G) and complemented earlier observations of other comets. The isotopic, elemental, and molecular abundances of the volatile, semi-volatile, and refractory phases brought many new insights into the origin and processing of the incorporated material. The emerging picture after Rosetta is that at least part of the volatile material was formed before the solar system and that cometary nuclei agglomerated over a wide range of heliocentric distances, different from where they are found today. Deviations from bulk solar system abundances indicate that the material was not fully homogenized at the location of comet formation, despite the radial mixing implied by the Stardust results. Post-formation evolution of the material might play an important role, which further complicates the picture. This paper discusses these major findings of the Rosetta mission with respect to the origin of the material and puts them in the context of what we know from other comets and solar system objects

Nitrogen isotope fractionation during magma ocean degassing: tracing the composition of early Earth’s atmosphere

International audienceThe evolution of the nitrogen concentration and isotopic composition during the degassing of Earth's magma ocean, and thus in the primitive atmosphere, is key to understanding how habitable conditions developed on Earth. To constrain nitrogen degassing from the magma ocean, we determined the variations of the N content at N 2 gas saturation, N speciation, and N isotopic composition of a magma ocean analogue (basaltic komatiite) at oxygen fugacities (fO2) from IW−4.2 to IW (where IW is the logarithmic difference between experimental fO2 and that at Fe-FeO equilibrium). We performed a series of N degassing experiments in a piston cylinder at 1.5 GPa and 1550°C in pure forsterite capsules. N concentrations in the mafic silicate melts decreased from 13,481 ± 735 ppm under the most reducing conditions to 798 ± 4 ppm at IW, controlled by N speciation (as determined by Raman spectroscopy), which changed from nitride (±N-H complexes) to molecular N 2 with increasing fO2. Nitrogen occurs solely as N2 in the degassed gas, regardless of fO2. Nitrogen isotopic compositions (as determined by secondary ion mass spectroscopy) became significantly lighter in the degassed melt (quenched glass), down to −41 ± 13 ‰ relative to the initial composition (measured in an undegassed sample), following open system degassing trends (variable with fO2 conditions), indicative of Rayleigh fractionation. These findings imply that an atmosphere in equilibrium with a reduced magma ocean would be N-depleted, whereas with increasing magma ocean fO2 conditions, the primitive atmosphere would have become more enriched in N2 gas

Corrigendum to “Recycling of crustal material by the Iceland mantle plume: New evidence from nitrogen elemental and isotope systematics of subglacial basalts” [Geochim. Cosmochim. Acta 176 (2016) 206–226]

In Table 1 of the above published paper, N2/40Ar* ratios (column 13) are incorrect. A corrected table and updated figures (Figs. 6–8) are shown below. The correct N2/40Ar* values vary between 178 and 2.6 X 10^4, with a mean of 4.1 ± 2.1 (X10^3). Although this range in N2/40Ar* ratios is somewhat smaller compared to what was reported, it still displays considerably more heterogeneity compared to the DMM database. The new mean value is also significantly higher than the DMM mean (138 ± 65), as discussed. Therefore, the findings in the paper concerning heterogeneous and elevated N2/40Ar* ratios in Icelandic subglacial basalts still stand

Carbon isotope and abundance systematics of Icelandic geothermal gases, fluids and subglacial basalts with implications for mantle plume-related CO2 fluxes

International audienceWe report new carbon dioxide (CO2) abundance and isotope data for 71 geothermal gases and fluids from both high-temperature (HT > 150 °C at 1 km depth) and low-temperature (LT < 150 °C at 1 km depth) geothermal systems located within neovolcanic zones and older segments of the Icelandic crust, respectively. These data are supplemented by CO2 data obtained by stepped heating of 47 subglacial basaltic glasses collected from the neovolcanic zones. The sample suite has been characterized previously for He–Ne (geothermal) and He–Ne–Ar (basalt) systematics (Füri et al., 2010), allowing elemental ratios to be calculated for individual samples. Geothermal fluids are characterized by a wide range in carbon isotope ratios (δ13C), from −18.8‰ to +4.6‰ (vs. VPDB), and CO2/3He values that span eight orders of magnitude, from 1 × 104 to 2 × 1012. Extreme geothermal values suggest that original source compositions have been extensively modified by hydrothermal processes such as degassing and/or calcite precipitation. Basaltic glasses are also characterized by a wide range in δ13C values, from −27.2‰ to −3.6‰, whereas CO2/3He values span a narrower range, from 1 × 108 to 1 × 1012. The combination of both low δ13C values and low CO2 contents in basalts indicates that magmas are extensively and variably degassed. Using an equilibrium degassing model, we estimate that pre-eruptive basaltic melts beneath Iceland contain ∼531 ± 64 ppm CO2 with δ13C values of −2.5 ± 1.1‰, in good agreement with estimates from olivine-hosted melt inclusions (Metrich et al., 1991) and depleted MORB mantle (DMM) CO2 source estimates (Marty, 2012). In addition, pre-eruptive CO2 compositions are estimated for individual segments of the Icelandic axial rift zones, and show a marked decrease from north to south (Northern Rift Zone = 550 ± 66 ppm; Eastern Rift Zone = 371 ± 45 ppm; Western Rift Zone = 206 ± 24 ppm). Notably, these results are model dependent, and selection of a lower δ13C fractionation factor will result in lower source estimates and larger uncertainties associated with the initial δ13C estimate. Degassing can adequately explain low CO2 contents in basalts; however, degassing alone is unlikely to generate the entire spectrum of observed δ13C variations, and we suggest that melt–crust interaction, involving a low δ13C component, may also contribute to observed signatures. Using representative samples, the CO2 flux from Iceland is estimated using three independent methods: (1) combining measured CO2/3He values (in gases and basalts) with 3He flux estimates (Hilton et al., 1990), (2) merging basaltic emplacement rates of Iceland with pre-eruptive magma source estimates of ∼531 ± 64 ppm CO2, and (3) combining fluid CO2 contents with estimated regional fluid discharge rates. These methods yield CO2 flux estimates from of 0.2–23 × 1010 mol a−1, which represent ∼0.1–10% of the estimated global ridge flux (2.2 × 1012 mol a−1; Marty and Tolstikhin, 1998)

Origin of nitrogen on Mars: First in situ N isotope analyses of martian meteorites

International audienceMartian meteorites are key for assessing the isotopic characteristics of nitrogen in different martian reservoirs (i.e., mantle, crust, and atmosphere), and, ultimately, for constraining the source(s) of nitrogen trapped during the earliest stages of planetary accretion in the terrestrial planet-forming region. In this study, we analysed, for the first time, the nitrogen content and isotopic composition of glassy melt inclusions of Chassigny and of the mesostasis of five nakhlites (MIL 03346, Nakhla, NWA 6148, NWA 998, and Y 000593) by in situ secondary ion mass spectrometry. The nitrogen content of Chassigny melt inclusions, corrected for olivine overgrowth on the inclusion walls, varies from 4 ± 1 to 860 ± 45 ppm N, and the majority of δ 15 N values range from-35 ± 41 to +73 ± 36‰. The estimated nitrogen isotopic signature of the primitive melt, prior to degassing of N 2 or NH 3 , is 0 ± 32‰. The mesostasis of nakhlites contains 2.7 ± 0.2 to 943 ± 156 ppm N, with δ 15 N values from-30 ± 37 to +348 ± 43‰. Whereas degassing of N 2 or NH 3 can explain the lowest nitrogen isotopic ratios measured in the nakhlite mesostasis, the 15 N-enriched isotopic composition (δ 15 N > 150‰) of four nakhlites (MIL 03346, Nakhla, NWA 6148, and Y 000593) likely results from interaction of the mesostasis melt with the martian atmosphere during ejection. The δ 15 N values (+25 ± 42 and +77 ± 19‰) of two melt inclusions in Y 000593 are comparable to those of Chassigny, further confirming that these meteorites likely sample a common volatile reservoir in the martian interior. Overall, the new results indicate that the chassignitenakhlite reservoir did not inherit nitrogen from the solar nebula but, instead, from chondritic-like materials. These findings further confirm that planetary bodies in the inner solar system accreted (isotopically) chondritic nitrogen during the first few million years of solar system history

Corrigendum to “Recycling of crustal material by the Iceland mantle plume: New evidence from nitrogen elemental and isotope systematics of subglacial basalts” [Geochim. Cosmochim. Acta 176 (2016) 206–226]

In Table 1 of the above published paper, N2/40Ar* ratios (column 13) are incorrect. A corrected table and updated figures (Figs. 6–8) are shown below. The correct N2/40Ar* values vary between 178 and 2.6 X 10^4, with a mean of 4.1 ± 2.1 (X10^3). Although this range in N2/40Ar* ratios is somewhat smaller compared to what was reported, it still displays considerably more heterogeneity compared to the DMM database. The new mean value is also significantly higher than the DMM mean (138 ± 65), as discussed. Therefore, the findings in the paper concerning heterogeneous and elevated N2/40Ar* ratios in Icelandic subglacial basalts still stand