22-EPN3-037: Alteration and Element Mass Transfer from Source to Sink in Planetary Crusts

Virtual visit by Astrid Holzheid (Kiel University, Germany) to TA2 Facility 23 – Open University Flow Through Simulation Chambers (UK).
Dates of visit: 19-23 February 2024

Report Summary: Sound knowledge of the processes and conditions that drive hydrothermal systems is one of the prerequisites to understand not only the geological, geochemical, and geophysical evolution of our planet and other terrestrial planets, especially Mars, but also to shed light on the origin and early evolution of life since hydrothermal systems can be hospitable to certain life forms.

The use of the unique experimental set-ups of the reaction chambers at Open University allows determination of the mass transport of dissolved metals with either continuous sampling of the fluid or recirculation the fluid with built-in Ti gaze as precipitation traps. We used this set up to better understand environmental conditions during active hydrothermal alteration.

The source rocks of the experiments were fresh basalts from the Indian ocean ridge that served as analogue material to the Martian surface. The fluid was Indian ocean seawater sampled 100m above seafloor.

We observed precipitation of minerals like Ca-sulphates, NaCl, FeOOH and Fe-Mg-Na-containing clay minerals, but also native Ta and Fe-Ni-Cr alloy. While the ions of the mineral phases originated from leaching of the basalt, the metals might have come from the stainless-steel tube that served as container of the Ti gaze.

Based on the newly formed minerals, the pH – redox state – conditions can be deduced. This information is a prerequisite together with the cations enriched in the post-run fluid phase to allow geochemical reaction-path modelling which will be the next step after the post-run fluids are analysed at Kiel University.

22-EPN3-092: Deciphering Traces of Life from the Dawn of Earth’s Biosphere

Visit by Nisha Ramkissooon (The Open University, UK) to TA2.2 VU (Exo)Planetary Interior Simulation Laboratory (PISL).
Dates of visit: 12-16 February 2024

Report Summary: In the search for evidence of ancient terrestrial life there are some obstacles. Purported biosignatures have been identified in a range of ancient mineral deposits, including silica. However, some of these signatures can also be generated under abiotic conditions, which brings into question their biological origin. In addition, the oldest fragments of the Earth’s crust are at least 3.8 Gyr, and would have experienced significant metamorphic alteration since their formation. Therefore, any preserved biosignatures could have also undergone extensive modification during metamorphism potentially making some of them unidentifiable. This project aimed to examine the effect of metamorphism on the modification of biosignatures preserved in silica deposits. 

Silica sinters were synthetically created in the laboratory via evaporation in the presence and absence of microbes. These samples were then exposed to simultaneous high temperature and high pressure conditions using the end-loaded piston-cylinder at the (Exo) Planetary Interior Simulation Laboratory (PISL), VU University, Amsterdam. Samples were individually subjected to pressures and temperatures of 650 °C and 12 kbar, respectively, for 20 hours. Raman spectroscopy and GC-MS will be used to assess changes in mineralogy and to quantify changes to organic molecules. Initial results obtained after returning to my home institution show that the high pressure and high temperature conditions experienced in these experiments led to changes in the crystalline structure of the samples. This resulted in samples transforming from silica glass to quartz. 

22-EPN3-124: Unfolding Geochemical Evolution of the Subcontinental Lithospheric Mantle Recorded by Diamond-Forming Carbon and Water Rich (C-O-H) Mantle Fluids Throughout Time

Virtual visit by Yael Kempe and Ofir Tirosh (The Hebrew University of Jerusalem, Israel) to TA2.1 VU Geology and Geochemistry radiogenic and non-traditional stable Isotope Facility (GGIF).
Dates of visit: 9 November 2023 – 25 January 2024.

Report Summary: Fibrous diamonds from the Voorspoed, Venetia and Koffiefontein mines record deep mantle events involving C-O-H fluid types, alongside gem diamonds containing mineral inclusions that were related to modification episodes of the Kaapvaal lithospheric region. Although a connection has been made, the longstanding debate between diamond formation in the mantle and the relationship between gem diamonds and fibrous diamonds is yet to be resolved.

While we have extensive radiometric dating of mineral inclusions trapped in gem diamonds, alongside knowledge about the major and trace elements of C-O-H fluid microinclusions in diamonds, their radiogenic isotopic data is insufficient (e.g. Sr, Nd, and Pb isotopes). High-precision Sr-Nd-Pb isotope TIMS analyses of C-O-H mantle fluids in diamonds from these three prime locations in the Kaapvaal craton were preformed using a novel laser ablation diamond-in-water technique, combined with ultra-low blank column chromatography and 10¹³ Ohm resistors.

The team successfully processed and analysed 12 samples from Voorspoed, 5 from Venetia and 5 from Koffiefontein mines, as well as standards and blanks. The collected data show intriguing Sr-Nd-Pb relationships that vary between diamonds carrying different C-O-H fluids. The team has further data processing and calculations to complete, as well as correlate the isotopic ratios with trace element compositions to fully understand the results and their geological significance. The outcome of this Europlanet project is expected to provide new insights into the complex tectonic history of this lithospheric province, the fluids themselves and the connection between different diamond types and their formation mechanism.

22-EPN3-063: The Origin of Early Archean Barite – Insights from the Geochemical and Isotopic Composition of Associated Chert Deposits

Visit by Desiree Roerdink (University of Bergen, Norway) to TA2.1 VU Geology and Geochemistry radiogenic and non-traditional stable Isotope Facility (GGIF).
Dates of visit: 6-10 November 2023

Report Summary: The formation of bedded barite (BaSO₄) deposits in the low-sulfate environments of the early Earth has been a long-standing paradox despite decades of field and geochemical studies. In this project, the team investigated the Si isotope geochemistry of chert (SiO₂) dykes and beds found in association with barite to evaluate roles of hydrothermal fluids and seawater during barite formation. A total of 14 chert samples from three localities in the ~3.3 Ga Mapepe and Mendon Formations of the Barberton Greenstone Belt, South Africa were microdrilled and dissolved using sodium hydroxide digestion. Pure silicon fractions were obtained using cation exchange chromatography columns, and analysed for ²⁹Si/²⁸Si and ³⁰Si/²⁸Si isotope ratios by multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) in wet plasma mode using standard-sample bracketing for mass bias correction. Measured silicon isotope ratios (δ³⁰Si) range from 0.27 to 1.29‰. Chert dykes (n = 6) and bedded cherts (n = 3) have similar silicon isotopic compositions, with an average δ³⁰Si value of 0.88‰ for the dykes and 0.80‰ for the bedded cherts. Black chert from the Mendon formation is isotopically distinct (δ³⁰Si = 0.45‰) from the Mapepe Formation cherts. These results tentatively suggest that the chert dykes and bedded cherts associated with barite formed from isotopically-heavy seawater (δ³⁰Si > 0‰), and that the role of high-temperature hydrothermal fluids (δ³⁰Si < 0‰) was limited. 

22-EPN3-005: Spatial Relationship Between Biosignatures and Their Geologic Context by Large-scale Geoscientific Mapping at Rio Tinto, Spain

Visit by Alessandro Frigeri (INAF, Italy) and Giacomo Panza (intern at INAF, University of Bologna, Italy) to TA1.2 Rio Tinto (Spain).
Dates of visit: 07-11 November 2023

Report Summary: Since the early 2000’s, Rio Tinto has been a critical witness plate for the investigation of extremophiles and it is recognized to be a mineralogical and geochemical analog of Mars (Amils et al., 2014). The Mars Analog Rio Tinto Experiment (MARTE), in particular, demonstrated that the Rio Tinto biosphere extends at least 900 meters below the land surface with a high potential of anaerobic microorganisms to be present (Stoker et al., 2008). Host rocks, however, are exposed at the surface in sediments and rocks of the Rio Tinto watershed, providing potential for key investigations.

The Rio Tinto 2023 field campaign was held between November 7th and November 18th 2023 at Rio Tinto Terrestrial Analogue. The campaign team was made by Alessandro Frigeri (INAF, Italy), James Skinner (USGS, US), Giacomo Panza (undergrad student at University of Bologna, intern at INAF) and Felipe Gomez as the TA Field expert (Centro de Astrobiologia, Madrid).

The campaign focused on geologic surveying and mapping the spatial relationship of the rocks where extremophile life develops today and has evolved through the geologic times. When bacteria proliferate within a solid media in a natural environment, microbial life alters the hosting environment chemically and physically. When the hosting media are soils and rocks, geological aspects like color, grain size, texture, and composition will be altered by the presence of life. Before the campaign, the team prepared a context cartographic base from remote sensing data from which they defined three sites of interest with different geological characteristics where to observe and map biosignatures.

In the field, the team applied traditional geological field large-scale mapping techniques coupled with photogrammetric drone surveys and drafted specific geoscientific mapping themes describing the geospatial setting of biosignatures at Rio Tinto Planetary Field Analogue in Spain.

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22-EPN3-77: Preservation of Organic Matter in Glacial Lakes: Implications for Martian and Icy Moon Biosignatures

Visit by Charlotte Spencer-Jones (University of Durham, UK) and Sevasti Filippidou (Imperial College London, UK) to TA1.4 AU Greenland Kangerlussuaq Field Site (Greenland).
Dates of visit: 25 July – 02 August 2023

Report Summary: In the search for extra-terrestrial life, environments that have previously contained water are a key target. Glacial environments, such as those found in Greenland, are highly dynamic ephemeral systems with a range of habitat types that support many different species, from bacteria and archaea to large mammals and higher plants. Organic carbon (OC) compounds, the fundamental building blocks of life, can be used to trace different species and/or biogeochemistry. The aim of the fieldwork campaign was to characterise OC in the lake water column to establish OC synthesis patterns in glacial lakes. In this study we collected water, sediment, and soils from 13 sites from a range of lake types near Kangerlussuaq, Greenland.The second phase of this study will be to characterise organic compounds within the samples. The outcome of this work will be to establish the key parameters that control organic compound preservation with the potential to impact the interpretation of putative extra-terrestrial biosignatures.

Read the full scientific report with kind permission by Charlotte Spencer-Jones and Sevasti Filippidou.

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22-EPN3-127: Silcrete deposits of the Kalahari Desert as potential analogs for silica-rich deposits on Mars

Visit by Maxime Pineau (Laboratoire d’Astrophysique de Marseille (LAM), France) and Simon Gouzy (Laboratoire de Planétologie et Géosciences (LPG), France) to TA1.5 Makgadikgadi Salt Pans (Botswana).
Dates of visit: 21-28 August January 2023

Report Summary: Hydrated silica occurs in various forms depending on the geological context and as such are good tracers for paleoenvironmental reconstitutions on Earth and Mars, as well as a prime exobiological target. Observed on Mars since the early 2000’s, hydrated silica minerals have been used to describe aqueous geological processes in diverse regions. However, geological origins of some deposits are still misunderstood because no satisfactory terrestrial analogues were found. Likewise, the exobiological potential of hydrated silica as a prime host of Mars organic matter remains to be fully ascertained.

The Makgadikgadi Salt Pans show a very high potential to be considered as a terrestrial analogue site for Mars hydrated silica, especially in fluvio-lacustrine geological settings. Maxime Pineau (LAM), Simon Gouzy (LPG), plus 2 other colleagues (Vassilissa Vinogradoff (PIIM) and John Carter (LAM)), spent 9 days at the pans (15 different locations) and sampled numerous samples (over 80s) of silicified clastic sedimentary rocks (i.e., silcretes) and conducted preliminary visible-near infrared spectra with a portable spectrometer.

Field observations and spectral analyses confirm the large amount of amorphous to (micro-)crystalline silica in the samples, along with different clays (e.g., glauconite, sepiolite) and salts (e.g., sulfates). This type of mineralogy, possibly indicating a formation in a fluvio-lacustrine context in semi-desert environments, is reminiscent of some silica-rich deposits on Mars in locations interpreted as potential paleo-lakes. These observations will be completed by further laboratory measurements (spectroscopy, microscopy, geochemical and organic analyses) in order to perform advanced studies in terrestrial geology, comparative planetology (e.g., Mars’ geology) and astrobiological exploration.

Read the full scientific report with kind permission by Maxime Pineau and Simon Gouzy.

22-EPN3-065: Ion Bombardment of Glycine and Glycine Embedded Within Water Ice in Solar System and Interstellar Conditions

Visit by María Belén Maté and Ramón Javier Peláez (IEM-CSIC, Spain) to TA2.12 Atomki-Queen’s University Ice Laboratory for Astrochemistry (Hungary).
Dates of visit: 07-11 November 2023

Report Summary: The possibility that prebiotic precursors of life formed in the space and were then transported to the early Earth by comets, asteroids and meteorites is a fascinating hypothesis. We focus in this project on hydroxylamine, NH₂OH, a key N-bearing species that has been proposed as an important precursor in the formation of amino acids like glycine or alanine. Very recently, hydroxylamine has been detected in the gas phase in dense clouds in the interstellar medium. It has been predicted to form efficiently on dust grains according to laboratory experiments and chemical models. Then, the presence of this species in ISM ices and on the surface of Solar System bodies is probable, and in those surfaces can react to form more complex prebiotic species like amino acids.

Although the chemical pathways leading to the formation of NH₂OH in astrophysical ices have been thoroughly studied, the next step in the chemical evolution that would begin with NH₂OH as a precursor in ice has, to our knowledge, not been addressed experimentally.

In this TA project the team studied the chemistry induced by Cosmic Rays on ices containing hydroxylamine. They studied pure NH₂OH ices and mixtures with H₂O, CO and D₂O, at 20 K, irradiated with 15 keV H⁺ ions. In particular, we were interested in finding complex organic molecules in the processed ices, and learning how different ice composition affects the chemistry and the destruction efficiency of NH₂OH by Cosmic Rays.

22-EPN3-065: Ion Bombardment of Glycine and Glycine Embedded Within Water Ice in Solar System and Interstellar Conditions

Visit by Alfred Hopkinson (Aarhus University, Denmark) to TA2.12 Atomki-Queen’s University Ice Laboratory for Astrochemistry (Hungary).
Dates of visit: 04-08 December 2023

Report Summary: During this TNA visit, the simplest amino acid glycine (NH₂CH₂COOH), and its deuterated analogs, partially deuterated d3-glycine (ND₂CH₂COOD) and fully deuterated d5-glycine (ND₂CD₂COOD), were irradiated using 10 KeV protons. The subsequent products of this processing were then measured using infrared spectroscopy and a quadrupole mass spectrometer. The aim of this was to investigate the products of glycine destruction and investigate if this energetic processing could result in the formation of glycine peptides. The outcome of the TNA visit was the collection of infrared spectra of the irradiation of these molecules and then following this, temperature-programmed desorption measurements. These preliminary results show the formation of CO₂, CO, and D₂O.

Full scientific report published by kind permission of Alfred Hopkinson.

22-EPN3-053: Proton Processing of Phenanthrene Ice Mixtures for Application to Titan’s Lower Atmosphere

Visit by Alessandra Candian and Annemieke Petrignani (University of Amsterdam, Netherlands) to TA2.11 Atomki Ice Chamber for Astrophysics / Astrochemistry (ICA) (Hungary).
Dates of visit: 4-8 March 2024

Report Summary: During this TNA visit, the three-ring PAH phenanthrene (C₁₄H₁₀), acetonitrile (CH₃CN) and their 1:1 mixture were irradiated using 10 KeV protons. The subsequent products of this processing were then measured using infrared spectroscopy (5000-700 cm-1) and a quadrupole mass spectrometer.

The aim of these experiments was to investigate 1) if energetic processing can modify the structure of solid hydrocarbons and 2) if proton irradiation could trigger the formation of new species. During the visit to Atomki, the team collected infrared spectra of at different proton fluences and then following this, infrared spectra during temperature-programmed desorption (TPD). They also obtained the residues after TPD for ex-situ analysis. The preliminary results show a) the puckering of phenanthrene solid, b) the formation of ethanimine (C₂H₅N) in acetonitrile solid, c) a complex behaviour of the 1:1 mixture, with puckering and formation of new hydrocarbon species.

Full scientific report published by kind permission of Alessandra Candian and Annemieke Petrignani.

22-EPN3-091: Evolution Under Radiation of Organics Pertaining to Europa

Visit by Alexis Bouquet (Aix-Marseilles University, France) to TA2.11 Atomki Ice Chamber for Astrophysics / Astrochemistry (ICA) (Hungary).
Dates of visit: 19-24 February 2024

Report Summary: Several of the icy moons of Jupiter possess a liquid water ocean under a thick icy crust. In the especially promising case of Europa, a young surface (>100 Myr), and likely recent cryovolcanicactivity (within the last 8 years) imply the presence of ocean material on the surface. Therefore, observations performed by space missions could determine the ocean’s composition, and derive indications on its potential habitability (presence of chemical gradients providing metabolic energy, quantity and composition of available organic matter…). Characterising Europa’s ocean and its possible habitability requires to understand processes that alter organic and inorganic molecules in this environment. These processes include the processing by energetic ions coming from Jupiter’s magnetosphere and hitting the surface.

In this project, Alexis Bouquet visited the Atomki facility to study the effect of sulfur ion bombardment on methanol, a species that could be indicative of key characteristics of the ocean, pure and within an ice matrix. The alteration of the sample was followed using infrared spectroscopy, and the resulting complex organic residues were retrieved for ultra-high resolution mass spectrometry.

Full scientific report published by kind permission of Alexis Bouquet.

22-EPN3-028 – Energetic Ion Processing of Pyrene Ice

Visit by Alicja Domaracka (CIMAP-CNRS, France) and Anna Bychkovato (Normandie Université, France) TA2.11 Atomki Ice Chamber for Astrophysics / Astrochemistry (ICA) (Hungary).
Dates of visit: 16-20 October 2023

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. There is a clear lack of information about interaction of energetic ions with pyrene in the solid phase.

In January 2022, Alicja Domaracka (CIMAP-CNRS, France) and Anna Bychkovato (Normandie Université) performed irradiations of pure pyrene 20 K by protons and carbon ions at the ATOMKI facility. Within the present TA, they studied pure pyrene ice at 20K irradiated with 6.4 MeV S³⁺, 4 MeV S²⁺, 2,4 MeV C²⁺, 400 KeV He⁺, 800 keV He⁺ and 800 keV H⁺ ion beams, respectively. In particular, we are interested in learning how the pyrene destruction cross sections depend on the projectile parameters (atomic number, energy).

20-EPN2-116: HIDISCC (Hypervelocity Impacts for DISC Calibration)

Visit by Vincenzo Della Corte, Osservatorio Astronomico Capodimonte Napoli, INAF (Italy), to TA2.7 Light Gas Gun Laboratory, University of Kent (UK)
Dates of visit: 27-29 March 2023

Report summary: The Comet Interceptor space mission is to launch in 2029 to study a dynamically new comet. Two of the three spacecraft involved will host copies of the Dust Impact Sensor and Counter
(DISC), which will measure the physical properties of cometary dust. The spacecraft’s velocity (7-70 km/s) will result in hypervelocity dust impacts on DISC. Combined with the range of dust particle sizes, this will create a wide range of impact momentum (10-11–10-3 kg/m/s). To cover the upper part of the momentum range, DISC calibration will be performed with hypervelocity simulated impacts induced by lasers. To perform DISC characterization and calibration in the lower momentum range, we carried out experiments at the Light Gas Gun Impact Facility at the University of Kent (UK).
To calibrate DISC and check the sensing element formed by the aluminum plate and the
piezoelectric transducers:

• We performed 9 shots at the Light Gas Gun Impact Facility at the University of Kent.
  We used different particle sizes and materials and different speeds, utilising different
  approaches, i.e. single particles with diameters down to 400 nm and buck-shots of a
  mixture of minerals and very light hollow spheres.
• The signals from the piezoelectrics will be used to verify DISC estimated
  performance and enable a generally-valid impact sensor calibration procedure.
  All 9 shots provided signals, this was for both single impacts and multiple buck- shot impacts.
  The results of the experiment confirmed the capability of the instrument to measure the
  momentum of particles impacting in the hypervelocity range.

Read the full scientific report, with kind permission from Vincenzo Della Corte.

22-EPN3-006: An Isotopic Inventory of Mars analogue environments

Visit by Michael Macey and Daniel Loy (OU, UK) to TA1.5 Makgadikgadi Salt Pans (Botswana).
Dates of visit: 17-25 January 2024

An international team of scientists from The Open University (OU) and the Botswana International University of Science and Technology (BIUST) conducted fieldwork across the Makgadikgadi Basin. The aim of the research conducted was to collect sediment cores and water samples to assess how viability of sulfur-cycling microbes varies across a gradient of salinities, desiccation, and UV-exposure, and how this might impact the formation of biosignatures. The timing of the trip allowed sampling across a spectrum of fluctuating environmental stressors in terms of the availability of water. During the trip, a total of 16 x 30 cm cores were collected for geochemical and microbiological characterisation. Furthermore, environmental variables were taken with pH, temperature, conductivity, redox potential, and UV monitored.  The trip was a success, with the collection of ideal samples to identify the relative abundance and diversity of sulfur cycling microbes across this analogue environment. 

Read the full scientific report with kind permission by Michael Macye and Daniel Loy.

22-EPN3-019: Investigation of Ceres Bright Spots – VIS-NIR Spectral Simulation of Haulani bright Areas by Means of Spectral Analysis on Produced Analogue Mixtures

Visit by Fabrizio Dirri and Giuseppe Massa (INAF-IAPS, Italy) to TA2.8 CSS (Cold Surfaces Spectroscopy) at IPAG (France).
Dates of visit: 22 May – 03 June 2023

Report Summary: In this project different bright areas of Haulani crater (i.e. Southern floor and Central Crater Peak, named ROI3 and ROI1) on Ceres have been studied by producing different analogue mixtures starting from previous results and comparing them with Dawn VIR data. The end-members have been identified based on previous studies (Tosi et al. 2018, Dirri et al. 2022) and the analogue mixtures have been produced with grain size 50-100 µm. The two initial mixtures, i.e. SF1 and CCP_#1 have been acquired in the VIS-NIR spectral range (0.4-4.5 µm) at T environment. The Band Center, Band Depth and FWHM of absorption bands at 2.7, 3.1, 3.4 µm, spectral slope (1.2-1.9 µm range) and reflectance level at 2.1 µm of the produced SFs and CCPs mixtures have been analysed and then compared with VIR data.

The best analogues are the SF_#5 and CCP_#6 mixtures and their spectra have been acquired at low temperatures, i.e. from 190K to 230K, similar to Haulani base temperature by using Cold Spectroscopy Facility (CSS) (IPAG, France). These mixtures exhibit values for the 2.7BD (Antigorite, Illite), 3.1BD (NH4-Montmorillonite) and 3.4 BD (NaCO3) similar to Haulani ROI3 and ROI1. In particular, different dark components have been used (i.e. magnetite plus carbon black) with the aims of better reproducing the Haulani spectral slope and reflectance level. Different carbonates mix involving trona, dolomite, hydrous and anhydrous natrite have been studied to assess their contribution to 2.7 µm spectral band and the three minima at 3.33, 3.42, 3.52 µm of Haulani ROI3.

22-EPN3-038: Asteroidal source(s) of L chondrites and its collisional evolution – U,Pb geochemistry of phosphates in meteorite Antonin.

Visit by Monika Kusiak (Institute of Geophysics Polish Academy of Sciences (IG PAS), Poland) and Agata Krzesinska (University of Oslo) to TA2 Facility 26 – KBSI Sensitive High Resolution Ion MicroProbe / SHRIMP-IIe/MC (South Korea).
Dates of visit: 12-23 May 23

Report Summary: The main goal of the visit was to conduct in-situ U-Pb geochronological study of phosphate minerals in the Antonin L chondrite. Fall of the Antonin, on 15th July 2021, was recorded by European Fireball Network, and this recording led to reconstruction of the pre-atmospheric orbit of meteoroid. The orbital parameters of the Antonin differ from reconstructed orbits of other L chondrites, but suggest it was sourced from the inner asteroid belt. To track the orbit to the parent body, it is important to understand dynamic collisions experienced, which are recorded in minerals of the meteorite. U-Pb dating allows to decipher details on events that led to resetting of phosphates.

During the visit to KBSI facility, we collected SHRIMP (Sensitive High-Resolution Ion MicroProbe) analyses within multiple apatite and merrillite grains. Initial U-Pb results show minor discordance of ages of phosphates, indicating a mild collision after the crystallization of the minerals. The timing of reset event cannot be inferred with high precision, but it likely occurred between 500–100 Ma.

Additionally, formation of phosphates can be well constrained from collected data at ca. 4450 Ma. This age implies that phosphates formed/recrystallized in response to a collision as impacts were the only source of heat after cessation of accretional activity. Altogether, the results suggest two collisions in the evolution of parent body and will be combined with further data to pinpoint key events in dynamical evolution of parent body of L chondrites.

22-EPN3-008: U/Pb-Dating of the Youngest Eclogites on Earth.

Visit by Linus Streichers and Willem van Westrenen (Vrije Universiteit Amsterdam, Netherlands) to TA2 Facility 26 – KBSI Sensitive High Resolution Ion MicroProbe / SHRIMP-IIe/MC (South Korea).
Dates of visit: 05 April 2023 – 01 May 23

Report Summary: A total of 184 U-Pb-ages of zircon from eclogites from Sulu-Dabie UHP metamorphic belt (China), the D’Entrecasteaux Islands (Papua New Guinea) and the Western Gneiss Region (Norway) were successfully determined using the SHRIMP IIe/mc of the Korean Basic Science Institute.

Using the concordia method, we could identify a concordant age of the peak metamorphism of eclogite from Sulu-Dabie of ca. 240 Ma. In addition, a discordant age of around 720 Ma could be identified, which may reflect the age of inherited, magmatic zircon cores. The zircon from the D’Entrecasteaux Islands revealed ages below 8 Ma, which is younger than ages previously measured on the same sample in a previous study. This makes this sample one of the youngest eclogites ever discovered on Earth’s surface. Zircons from the Western Gneiss Region reveal ages of three distinct events. With 1.5 Ga, the oldest age determined probably reflects the Precambrian formation of the UHP region, while ages of around ca.

900 Ma correspond with the Sveconorwegian orogeny. The youngest age found in Norway reflects the Scandian orogeny at an age of ca. 415 Ma. The age information obtained will help us to develop improved evolutionary models for the formation of UHP rocks by combining these ages with trace element data.

22-EPN3-105: At the interface of ice and water on Mars – Insights from Western Greenland.

Visit by Anna Grau Galofre (CNRS/Laboratoire de Planétologie et Géosciences, France) and Axel Nobletto (Western University, Canada) to TA1.4 AU Greenland Kangerlussuaq Field Site (Greenland).
Dates of visit: 25 July – 02 August 2023

Report Summary: The aim of this project was to investigate elements of the glacial and periglacial system surrounding Kangerlussaq, Western Greenland, to then compare them to similar landforms on the surface of Mars.

The first target in the field focused on investigating former subglacial drainage pathways that would have transported and accumulated water under the western Greenland ice sheet (GIS). Preliminary field observations, consisting of field and UAV imagery, mapping of former ice flow directions and sediment analyses, identified sets of bedrock incised depressions, linked by shallow channels that often cross drainage divides, point at a former subglacial drainage setting consisting of interlinked subglacial cavities. These observations would be consistent with present day radar observations of drainage
pathways under the western GIS margin near Kangerlussuaq. Beside their interest for understanding the geometry of current subglacial drainage under Greenland, interlinked subglacial cavities are also interesting analogues to the martian so-called fresh shallow valleys, which are suggested to have formed under former ice cover.

The second field objective investigated polygonal terrain, its morphology, distribution, and the connection with the depth to the ice layer. We studied polygonised terrains around Kangerlussuaq, collecting image data, structure-from-motion, and depth to the ice layer. We also mapped the distribution of polygonal terrain as observed in the field and aerial imagery.

The results and interpretations will be applied to the study of Martian polygons, to propose a model of the buried ice conditions for Mars’ permafrost, and the development of channel systems.

Read full scientific report with kind permission by Anna Grau Galofre.

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22-EPN3-049: Retrieving multiple ice cores covering the last 100 years to study the link between the solar cycle and the cosmogenic tritium in precipitation.

Visit by László Palcsu and Marjan Temovski (Institute for Nuclear Research, Hungary) to TA1.4 AU Greenland Kangerlussuaq Field Site (Greenland).
Dates of visit: 19-23 June 2023

Report Summary:

The objective of the mission was to retrieve multiple ice cores at the EGRIP site (75°37′N, 35°59′W, 2702 m a.s.l.) to study the natural as well as anthropogenic variation of tritium in the ice layers. We have studied the recent publications, which suggest lower snow accumulation rate than what we have previously thought. Therefore, we intended to drill more shallow cores. During five days at EGRIP (19-23 June 2023), we drilled five 24 m-long ice cores representing the last 100-110 years. The ice cores were cut into subsamples of 15 cm, and packed into plastic containers. One full core was collected. The bottom part (depth between 16.2 and 24.0 m) of the additional 4 cores was also collected to get more material for sensitive analysis of tritium by the ³He-ingrowth method.  Altogether 368 samples have been collected. Besides the cosmogenic tritium, stable isotopes of water, and Sr-Nd-Hf isotope signatures will be also analysed. To compare this latter to older ice (>10,000 years), we took ice samples at the ice margin in a location between the glaciers Isunnguata Sermia and Russell about 36 km from Kangerlussuaq, near Point 660. The ice there is supposed to be around 40,000 years old. We drilled a shallow core (~ 4 m), cut into 10 pieces, and stored in pre-cleaned plastic vessels. All of the ice samples have been already shipped to our laboratory in Hungary. The first analyses for stable isotopes, ¹³⁷Cs around the Chernobyl event, and tritium around the bomb-peak have been already started.

Read full scientific report with kind permission by László Palcsu.

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22-EPN3-129: In-situ and laboratory spectroscopic characterisation of Icelandic lava flows; an analogue of Venus – VERITAS mission preparation

Nils Mueller and Akin Domac (German Aerospace Center (DLR), Germany) to TA1 – Iceland Field Sites, MATIS
Dates of visit: 1-7 August 2023

As part of collaborative field work of the VERITAS science team, Nils Mueller and Akin Domac visited several locations with partially sediment covered lava flows in the vicinity of Askja, Vatnajokull National Park, Iceland. This was done simultaneously with an airborne radar campaign by the German Aerospace Center {DLR. e.V.) acquiring synthetic aperture radar images at X- and S-band, the wavelengths of the radar instruments on the Venus orbiters VERITAS and Magellan, respectively. The objective of the field­work was to document the nature and extend of sediment cover on lava flows and how it affects scattering and roughness at radar wavelengths. This will improve the combined Magellan/VERITAS SAR image interpretation by providing in-situ data that can be tied to specific S and X band backscatter values. Another aspect is change detection as the same airborne radar collected data of the near pristine Holuhraun lava flow in 2015.

The field work data collected includes photos, notes, LIDAR scans of SxS m2 patches, and clast and sediment samples from the the surface and, if possible, from 20 cm depth. The initial observations show that parts of the Holuhraun lava flow have been significantly modified by aeolian sediments in the 8 years since the end of the eruption. These sediments affect the roughness on radar wavelengths but also radar backscatter via changes in composition, density, clast size, and water content. Whether the changes are notable in the radar images remains to be seen, as the interpretation is ongoing.

Photos from the campaign can be found in the DLR Flickr Album: VERITAS – Expedition for NASA & ESA Missions to Venus: