22-EPN3-096: Constraining the thermal history of the CY chondrites through ion probe analyses of Ca-phosphate grains

Virtual visit by Ashley King of the Natural History Museum, London (UK) to TA2.9 Ion Probe Facility (IPF), CRPG (France)
Dates of visit: 29 January – 2 February 2024

Report Summary: The CY carbonaceous chondrites experienced extensive parent body aqueous alteration followed by a metamorphic event(s) at temperatures >500°C. Based on their petrographic and chemical properties, they are closely related to the CI chondrites and samples returned from Ryugu; however, the specific conditions under which they were altered remain unconstrained. In this study, we analysed the water and fluorine abundance and hydrogen isotopic composition of 29 apatite grains in three CY chondrites to better understand their distinct aqueous and thermal histories.

The composition of the apatite grains and surrounding phyllosilicate-rich matrix was analysed using SIMS at CRPG. Water and fluorine abundances ranged from 0.7 to 4.6 wt.% and 0.03 to 1.8 wt.%, respectively, while δD values ranged from −102 to +343 ‰. Apatite grains in Y-86029 have the highest H2O abundances and lowest δD values, possibly due to hydrogen diffusion and isotopic fractionation during thermal metamorphism. This suggests that Y-86029 reached a higher peak metamorphic temperature and/or was heated for longer than the other CY chondrites. However, potential contamination of our analyses by the matrix and/or epoxy in which the samples are embedded also needs to be taken into account.

22-EPN3-093: The Origin of Metal-Rich Brine Component in the Ontong Java Plateau Magmas – Ion Probe Study of Boron Isotopes and Halogen Abundances in Volcanic Glasses

Virtual visit by Maxim Portnyaginy of the GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany) to TA2.9 Ion Probe Facility (IPF), CRPG (France)
Dates of visit: 4-8 December 2023

Report Summary: We used a multi-collector ion probe CAMECA IMS 1270-E7 at CRPG, Nancy, to analyse boron isotope composition and bromine concentrations in a representative set of 20
Ontong Java Plateau volcanic glasses. The visit was virtual on agreement with the host lab.

The results were achieved within the granted period of analytical time. The data revealed wide variations d11B in glasses from –8.6 ‰ to +12.6 ‰. Strong correlations were found between d11B and Cl/K (positive correlation) and between d11B and K/B (negative correlation). The concentrations of Br in the OJP glasses were found to range from 0.9 to 8.3 ppm. The Br contents correlate strongly with Cl contents so that the Br/Cl ratio in glasses is relatively constant and ranges between 3.1–4.9×10-3. The new data allowed us to propose three possible alternative scenarios for the origin of halogen- and metal-rich
component involved in OJP magmatism, which are following: (1) the magmas might have assimilated seawater-derived salt with lower δ11 B than that of the seawater, (2) the magmas assimilated initially high-δ11 B and high Br/Cl brines, which might have changed their compositions to lower values due to interaction with low-δ11 B and low Br/Cl crustal rocks before interaction with OJP magmas, and (3) the magmas assimilated brines derived from seawater with lower δ11 B during the Cretaceous than that of the modern seawater. The hypotheses will be elaborated in future studies.

20-EPN-046: iVOL – Impact-induced volatile release from calcium sulphates anhydrite and gypsum re-investigated in an open system by two-stage light-gas gun impact experiments

Virtual visit by Christopher Hamann and Robert Luther of Museum für Naturkunde Berlin (Germany), to TA2.7 Light Gas Gun Laboratory, University of Kent (UK)
Dates of visit: 01 September 2021 – 01 May 2022

Clarifying the response of volatile-bearing materials such as sulphates and carbonates to hypervelocity impacts is important, as it relates to the potential modification of planetary atmospheres by release of volatiles. However, most previous studies aimed at delineating the shock behaviour of sulphates and carbonates were done using confined or ‘closed’ setups (e.g., shock-recovery experiments) that hampered formation and escape of volatile species resulting from shock compression and subsequent release. Here, we focus on calcium sulphates, which are abundant on Earth and Mars and are likely targets of hypervelocity impacts. 

By using the two-stage light-gas gun at the University of Kent Light Gas Gun Laboratory, we investigated the response of gypsum (CaSO₄⋅2H₂O) and anhydrite (CaSO₄) to hypervelocity impacts in a fully unconfined or ‘open’ system that allowed impact-induced formation and escape of volatiles such as H₂O and SO₂/SO₃ as well as recovery of shocked materials. By petrographic investigation of shocked, solid ejecta and materials lining the impact craters, we find that dehydration of gypsum to anhydrite proceeds via bassanite (CaSO₄⋅0.5H₂O) and results in distinct changes of microtextures (e.g., dehydration cracks) and Raman spectra (e.g., weakening of water Raman bands). In addition, further devolatilization of sulphur-bearing species from anhydrite or solid dehydration products as well as melting is suggested from a distinct Ca-enrichment in µXRF element distribution maps and certain microtextures (e.g., spherical objects resembling melt spherules) observed under the SEM, respectively. These characteristics may be used to identify shocked calcium sulphates among terrestrial or extraterrestrial (e.g., future Martian) samples.

20-EPN2-057: A Zircon Provenance Study of the Kanye Basin (Botswana) to Constrain Terrestrial Geodynamics Across the Archaean-Proterozoic Transition.

Virtual visit by Denice Borsten and Jochem Sikkes (Vrije Universiteit Amsterdam, Netherlands) to TA2 Facility 26 – KBSI Sensitive High Resolution Ion MicroProbe / SHRIMP-IIe/MC (South Korea).
Dates of visit: 23 September 2021 -17 February 2022

Report Summary: This study investigates the Neoarchaean to Paleoproterozoic Transvaal Supergroup sedimentary sequence in Botswana that formed in the centre of the Kaapvaal Craton during the early oxygenation of the atmosphere. We used U-Pb dating on magmatic and sedimentary zircons from throughout the sedimentary sequence to determine the tectono-magmatic evolution of the hinterland basement. This approach constrains regional crustal growth, uplift and erosion events and establishes if additional cratons were in the hinterland, e.g. Pilbara. Knowledge of zircon provenance will allow critical comparison to known tectonic scenarios, e.g. Alpine style molasse basin and any potential change in Neoarchaean tectonics by considering erosion and crustal growth-reworking. The geochronology results help evaluate spatial and temporal variations in depositional environments associated with oxygenation of the atmosphere. Results indicate that the age of the basement, Gaborone Granite and the Kanye volcanic are indistinguishable (2768.9 ± 6.0 Ma). Sediments deposited from 2.642 Ga to 2.550 Ga are also dominated (> 90%) by zircons of ~2.77 Ga. This implies that there was a major crustal growth event in the Kanye region at 2.77 Ga that included minimal crustal reworking. Erosion products to the Kanye Basin are derived from this juvenile crust throughout the Archaean and Proterozoic until > 2.0 Ga.  Only then are older and younger basement rocks recorded in the sedimentary sequence. This region of the planet yields no evidence of a major tectono-magmatic event associated with the oxygenation of the atmosphere. 

20-EPN-049: The Irradiation of Oxygen-Bearing Ices on Top of Pure Elemental Sulphur Layers (former title: Millimetre-Wave Polarimetry of Space Relevant Ices Exposed to Energetic Ions)

Virtual visit by Olivier Auriacombe, Chalmers University of Technology (Sweden), to TA2.11 Atomki Ice Chamber for Astrophysics / Astrochemistry (ICA) (Hungary).
Dates of visit: 20 June – 4 September 2022

Report Summary: The chemistry of sulphur in icy extra-terrestrial settings such as the dense interstellar medium and the outer Solar System remains poorly constrained. In particular, the chemical routes towards the formation of SO₂ ice (and other volatile sulphur-bearing species) is not completely understood, despite the detection of this species in interstellar icy grain mantles, on the surface of Europa, and on comets. We have therefore explored the possibility of forming SO₂ ice as a result of the irradiation of oxygen-bearing ices (including O₂, CO, CO₂, H₂O, and CH₃OH) deposited on top of pure elemental sulphur layers, both of which are known to exist in the dense interstellar medium and the outer Solar System where radiation chemistry may be engendered by galactic cosmic rays or the solar wind. 

Our results demonstrate that SO₂ may indeed be produced after the 1 MeV He⁺ ion irradiation of O₂ and CO₂ ices deposited on top of elemental sulphur, but not as a result of similar irradiations conducted using CO, H₂O, or CH₃OH ices. Other volatile radiation product species incorporating sulphur, such as CS₂, OCS, and H₂SO₄, were also detected in different experiments. Our work should therefore contribute to a better understanding of solid-phase sulphur astrochemistry and the role of elemental sulphur in the formation of volatile sulphur-bearing species in icy extra-terrestrial settings.

20-EPN2-045: Irradiation Effects of Energetic H⁺ and S⁺ Ion Implantation in Salts and Minerals Relevant to the Surface of Europa

Virtual visit by Duncan Mifsud, University of Kent (UK) to TA2.11 Atomki Ice Chamber for Astrophysics / Astrochemistry (ICA) (Hungary).
Dates of visit: 21-29 November 2022 and 18-20 January 2023

Report Summary: The surface of Europa is host to a rich radiation environment, in which ions from the giant Jovian magnetosphere drive physico-chemical transformations of surface ices and minerals. Although a number of previous studies have looked into the irradiation of surface ice analogues in order to better constrain the chemistry occurring on Europa, considerably fewer studies have investigated the radiation chemistry of plausible mineral analogues.

Therefore, in this study, we have irradiated four mineral species (halite, fayalite, epsomite, and berthierine) using 1 MeV H⁺ and 1 MeV S⁺ ions to better understand the dissociation pathways of these minerals and the associated radiolysis products. Our preliminary results have shown that irradiation brings about significant changes in the appearances of the minerals that signify alterations in the structures and chemical compositions. Further infrared, visible, and ultraviolet spectroscopic analyses of retained mineral samples (both irradiated and pristine) are planned for the near future.

20-EPN-025: Radioresistance of aromatic complex organic molecules (nucleobases)

Virtual visit by Alicja Domaracka and Anna Bychkova, CIMAP-CNRS (France) to TA2.11 Atomki Ice Chamber for Astrophysics / Astrochemistry (ICA) (Hungary).
Dates of visit: 17-28 January 2022

Report Summary: Over the last decades it became clear that we live in a “molecular universe”. Carbon forms the basis of the majority of the molecular species that so far have been identified in space. Although small carbon-based molecules, like CO and CO₂, are some of the most abundant molecules in space, only a small fraction of the carbon is expected to be locked up in such species. It was proposed that a large portion of the interstellar carbon, up to 20%, is built in polycyclic aromatic hydrocarbons (PAHs) and fullerenes. Several laboratory studies were carried out to investigate the effects of vacuum ultraviolet photolysis on PAH:H₂O ices. However, data about interaction energetic ions with PAH ices are very scare.

We therefore studied the radiolysis of the pure pyrene ice and mixed pyrene- water ices at different concentrations at 20 K with 200 keV and 2 MeV H⁺ and 2 MeV C²⁺ beams at Atomki. The preliminary analysis of water-pyrene ices irradiated 200 keV H⁺ (with pyrene concentration from about 5 to 100% of pyrene) indicates that pyrene is more radio-resistant at high concentrations. The results are preliminary and analysis is ongoing.

20-EPN2-081: Vis-NIR reflection spectroscopy of ammonium salts relevant for icy planetary surface characterisation

Virtual visit by Maximiliano Fastelli, University of Perugia (Italy), to TA2.8 CSS (Cold Surfaces Spectroscopy) at IPAG (France).
Dates of visit: 13 October – 5 November 2021

Report Summary: During this TA visit under Europlanet 2024 RI 2nd call, reflectance VIS-NIR spectra of several ammonium salts were collected at the CSS facility (IPAG laboratory) in Grenoble, France. Different temperature steps were chosen to collect cryogenic data down to 90 K. Samples were characterised by low temperature crystalline phase transitions, and for these reasons, the measurement steps have been increased in the proximity of the expected temperature of mineral transformation. Cooling and heating experiments, using the same cooling/heating rate, were performed to bracket the phase transition T and verify its reversibility. All the spectra were collected with three different grain size (150/125 – 125/80 – 80/32 μm) in the spectral range from 1 to 4.6 μm at low T. Typical absorption features due to overtones and combinations of NH₄⁺ groups were identified in the spectral range investigated. Phase transitions, when detected, show an interesting behaviour with change in shape and position of some (sensitive) absorption bands which could be useful for the identification of these phases at non-ambient T. Moreover, the effect of low T and different granulometry were observed.

It has been proposed that ammonium minerals are present in varying percentages in icy planetary bodies. The availability of these compounds is linked to the upwelling of ammonium salts (NH₄⁺) with ice from the subsurface of possible oceans resulting from cryovolcanism phenomena. The identification of these minerals on the surface can give information about internal composition/dynamics and potential habitability of icy bodies.

20-EPN-029: VIS-NIR reflectance analysis of analogue mixture representative of young Haulani crater on Ceres to assess the mineralogical composition of bright areas.

Virtual visit by Fabrizio Dirri, IAPS-INAF (Italy), to TA2.8 CSS (Cold Surfaces Spectroscopy) at IPAG (France).
Dates of visit: 15-26 March 2021

Report Summary: In this project different bright areas of Haulani crater (e.g. Southern floor, i.e. ROI3 and North-east crater wall, i.e. ROI4) on Ceres have been studied by arranging different analogue mixtures and comparing them with Dawn VIR data. The end-members have been identified based on previous studies (Tosi et al. 2018, 2019) and the analogue mixtures have been produced with grain size 50-100µm for two bright crater regions. The two initial mixtures have been acquired in the VIS-NIR spectral range (0.35-4.5µm) at low temperature, i.e. from 200K to 300K similar to Haulani by using Cold Spectroscopy Facility (CSS) (IPAG, France). 

By comparing the spectral parameters (Band Center, Band Depth and FWHM of absorption bands at 2.7, 3.1, 3.4µm, spectral slope in the 1.2-1.9µm range and reflectance level at 2.1µm) with the obtained spectra of mixtures and VIR data, the best candidate to reproduce Haulani’ bright areas is the mixture A3-8. That mixture exhibits values for the 2.7BD (Antigorite, Illite), 3.1BD (NH4-Montmorillonite), 3.4 BD (NaCO₃) and the 3.1 µm FWHM very close to Haulani ROI3 and ROI4. In order to better reproduce Haulani areas some improvements may be performed in the next future, e.g., by changing the dark component with a mixture of graphite plus magnetite to better reproduce the spectral slope of Haulani or by adding hydrous natrite in low percentage to the mixture, e.g. 2-8% to assess the role of this component found in Haulani bright areas and how is the contribution to 2.7 µm spectral band.

Read full report (published with kind permission of Dr Dirri).

20-EPN-042: Reflectance spectroscopy of ammonium-bearing minerals – A tool to improve the knowledge of the surface of icy planetary bodies.

Virtual visit by Maximiliano Fastelli, University of Perugia (Italy), to TA2.8 CSS (Cold Surfaces Spectroscopy) at IPAG (France).
Dates of visit: 09-27 November 2020

Report Summary: In the frame of the Europlanet 2024 1st TA call, reflectance VIS-NIR spectra were collected. Ten different temperature steps were chosen to collect cryogenic data: 270-245-220-180-160-140-120-100-90-270 up K.

For the samples characterized by a low temperature phase transitions (mascagnite (NH₄)2SO₄, sal-ammoniac NH₄Cl, ammonium phosphate (NH₄)H₂PO₄, tschermigite (NH₄)Al(SO₄)₂·12(H₂O) and ammonium nitrate NH₄NO₃), the measurement steps have been increased in the proximity of the expected temperature of mineral transformation. Cooling and heating experiments, using the same cooling/heating rate, were performed to break the phase transition T. In particular, mascagnite, sal-amoniac and ammonium phosphate monobasic samples showed clear and very interesting spectral bands variations during cooling, indicating that a phase transition occurred. Spectra were collected with three different grain size (150/125 – 125/80 – 80/32 μm) in the spectral range from 1 to 4.8 μm. 

The collected data will help on the interpretation of VIR remote spectra from Europa, Pluto’s moons, Enceladus and other icy celestial bodies surface where NH4 minerals have been supposed to occur. Moreover, the study of ammonium bearing minerals and their behavior at very low temperature might give information on how the phase transition affects the bands position and shapes inside the reflectance spectra. Overtones and combinations of NH₄ bands are in the 1-3 μm range, whereas fundamental vibrational modes (ν₁ and ν₃) are present in the ~3 μm area.

20-EPN2-088: High spectral resolution / low-temperature IR study of carbonates.

Virtual visit by Simone De Angelis and Cristian Carli, IAPS-INAF(Italy), to TA2.8 CSS (Cold Surfaces Spectroscopy) at IPAG (France).
Dates of visit: 11 May – 04 June 2021

Report Summary: We planned to acquire reflectance spectra of anhydrous carbonates in the infrared range (3.2-4.6 μm), at high spectral sampling/resolution and at different cryogenic temperatures in the range 60-270K. 

The analysed materials were calcite, dolomite, siderite, natrite, malachite and magnesite; all the minerals were prepared and measured at fine powders, d<50 μm.  These measurements provide new spectral data in the IR that will be useful in the interpretation  of remote-sensing spectroscopic observations of Solar System rocky bodies such as Mars, Jovian satellites and minor bodies by current and future missions (Mars 2020, ExoMars-2022, JUICE, Europa Clipper, OSIRIS-REx).