Tag: ta2.9

22-EPN3-080: Chronology, Evolution of CAIs in Ordinary Chondrites

Visit by Francois Holtz of Leibniz University of Hanover (Germany) to TA2.9 Ion Probe Facility (IPF), CRPG (France)
Dates of visit: 02-09 February 2024

Report Summary: This study investigates naturally quenched and experimentally homogenised olivine-hosted melt inclusions (OLHMIs) from different geodynamic settings. Using SIMS analysis at CRPG, Nancy, we measured H₂O and CO₂ contents of OLHMIs from Loihi Seamount, Etna, and Klyuchevskoy volcanoes. Values were adjusted using natural and synthetic glass references to account for compositional effects. OLHMIs from Loihi seamount pillow lavas showed H₂O contents comparable to published data. Experimental heating led to significant H₂O loss over time, with near-complete loss after 5 hours. Additionally, we analysed OLHMIs from Etna volcano for Br contents, adjusting with calibration from low-Br Macquarie MORB glasses and high-Br synthetic basaltic glasses. Br analysis exhibited a linear calibration with high accuracy. OLHMIs from etnean FS tephra had relatively low Br contents, with a slightly elevated Br/Cl ratio compared to mantle values. These findings contribute to our understanding of volatile behaviour in magmatic systems and offer insights into volcanic processes.

22-EPN2-036: Chronology, Evolution of CAIs in Ordinary Chondrites

Visit by Ritesh Kumar Mishra of the Veer Kunwar Singh University, Ara, Bihar (India) to TA2.9 Ion Probe Facility (IPF), CRPG (France)
Dates of visit: 13-17 November 2023

Report Summary: The first forming Solar System solids are the refractory oxides and silicates of calcium, aluminium, titanium and magnesium which give them their eponymous name Calcium, Aluminium-rich Inclusions (CAIs). Only a few (~50), mostly very small (~20-50 microns) have been found in Ordinary chondrites. Our extensive search for large CAIs in ordinary chondrites resulted in finding about 10 CAIs in Semarkona (LL3.00), ALHA81251 (LL3.3), Chainpur (LL3.4). Three Oxygen isotopic (Δ¹⁷O) studies along with ²⁶Al-²⁶Mg short-lived now extinct chronology were carried in 4 CAIs and 2 Al-rich chondrules to decipher their genesis and provenance and make comparative analysis with the vast amount of previous data from the carbonaceous chondrites.

22-EPN3-047: Vein networks in the Variscan foreland basins in western Europe

Visit by Jeroen van der Lubbe of the Vrije Universiteit (Netherlands) to TA2.9 Ion Probe Facility (IPF), CRPG (France)
Dates of visit: 13-17 November 2023

Report Summary: The primary objective of the proposed research is to investigate the mechanisms of fluid and trace metal transportation from the deeper orogen to the mid-upper crustal levels. These levels are particularly significant as they are known to host mineralisation, including metals that play a crucial role in facilitating the energy transition. In this research, an examination is conducted on samples of quartz veins originating from the High Ardennes Slate Belt in the Rursee region of Germany, as well as its equivalent in Almograve, Portugal. The objective is to establish limitations on the movement of fluids and elements within upper crustal settings. The presence of veins in our research among allochthonous terranes with a peri-Gondwanan affinity provides support for the hypothesis that these veins may have originated from the same sources during the Variscan orogeny.

This research is a component of the ITN FluidNET initiative, which seeks to comprehend the fluid mobility and elemental transport across various levels of the Earth’s crust, including the lower, middle, and upper sections. The current investigation is done on context of the doctoral study of Akbar Huseynov, who focusses on the fluid migration and vein formation in the upper crust. The FluidNET project aims to validate its overarching hypotheses by employing various isotopic techniques involving radiogenic and stable isotopes, examining trace element distributions within fluid inclusions, and conducting geochronological analysis of fluid inclusions. These methods enable the project to trace the migration of fluids across a range of scales, from nano- to kilometres. The primary objective of this study is to enhance our understanding about the transport fluxes of metals that are crucial to current energy transition. To do this, the research aims to integrate fluid transport across temporal and spatial dimensions via the use of analytical and numerical methodologies.

22-EPN3-064: Investigating Oxygen Isotopes within Ca-Al-rich inclusions (CAIs) and Compound-Chondrule-CAI (CCCAIs) Populations within CM chondrites

Visit by Pierre-Etienne Martin and Luke Daly of the University of Glasgow (UK) to TA2.9 Ion Probe Facility (IPF), CRPG (France)
Dates of visit: 24-28 April 2023

Report Summary: Compound-chondrule-Calcium-Aluminium-rich Inclusions (CCCAIs) are rare occurrences within carbonaceous chondrites. They have been reported sporadically within most major groups (CO, CV, and CH) and only described four times within CM (Mighei-like) carbonaceous chondrites of various degrees of aqueous alteration, such as Aguas Zarcas (CM2; Martin & Lee, 2021) and Paris (CM2.7; Rubin, 2015). These objects have been described as CAIs enclosing chondrules or as chondrules enclosing CAIs. The existence of CCCAIs suggests that chondrules and CAIs interacted within high particle density environments in the protoplanetary disk prior to their incorporation into their mutual parent bodies.

In this study, we investigated two such objects within the Aguas Zarcas meteorite using oxygen isotope
analysis in order to characterize the CAI and chondrule components of the CCCAIs in comparison with CAIs and chondrules within the rest of the two Aguas Zarcas samples. Results show that the CAI and chondrule components of CCCAIs originate from the same O isotope reservoirs as their regular counterparts, suggesting that no isotopic exchange occurred between the two types of components, and that the components originate from the same O isotope reservoirs as the CAIs and chondrules of the meteorite breccia. An exception is the ‘Cicero’s’ chondrule part, which has a very primitive O isotope composition similar Amoeboid Olivine Aggregate (AOA). Due to the very primitive O isotope composition of AOAs, their formation is thought to have occurred in a near-solar environment. Further evidence is needed, but the existence of these objects can better our understanding of the evolution of the protoplanetary disk and provide a new way to study the chondrule forming environment(s).

20-EPN2-072: Dynamics of the early inner solar system inferred from combined 26 Al-26 Mg and Cr–Ti–O isotope systematics of non-carbonaceous chondrules

Visit by Christian Jansen, WWU Münster (Germany) to TA2.9 Ion Probe Facility (IPF), CRPG (France).
Dates of visit: 03-12 August 2022

Report Summary: The advent of non-traditional isotopic systems (e.g., Ti, Cr, Mo) revealed that chondrites—the most primitive witnesses of the early solar system—display a fundamental isotopic dichotomy, with carbonaceous chondrites (CCs) showing large nucleosynthetic anomalies relative to terrestrial standards that are not observed in non-carbonaceous chondrites (NCs). NC and CC reservoirs may thus represent the primordial inner and outer parts of the solar system, respectively. 

The scientific goal of this project is to combine several isotopic systems (O, Ti, Cr) for deciphering the conditions and chronology of chondrule formation in the NC reservoir. A key parameter of this approach is to also have access to the formation ages of these chondrules. This requires in situ measurements with a secondary ion mass spectrometer for determining the ²⁶Al ages of chondrule crystallisation.

To do so, 16 chondrules were separated from the minimally altered ordinary chondrite NWA 5206. They were split into two pieces for determining their (i) Cr and Ti isotopic compositions (bulk measurements) and (ii) O isotopic compositions and ²⁶Al ages. These chondrules show no ⁵⁴Cr or ⁵⁰Ti excesses and classical oxygen isotopic composition (with ∆¹⁷ O ranging from -1 to + 1 ‰). ²⁶Al ages are coherent with previous estimates showing that NC chondrules formed over several million years during the evolution of the inner disk.

20-EPN2-102: A new source of water from Mars

Visit by Tim Tomkinson, University of Bristol (UK) to TA2.9 Ion Probe Facility (IPF), CRPG (France).
Dates of visit: 05-09 December 2022

Report Summary: Here we have searched for a source of D-enriched Martian groundwater previously discovered in the Martian meteorite Lafayette (up to δD 4725‰) within olivine defects below the secondary mineral phyllosilicate. These groundwaters which are known flowed through this sample 670 Ma were sourced from the Martian atmosphere, or had equilibrated with it, and diffused up to ~1.5 µm into the olivine via shock-formed defects in vein walls. In this project we want to determine a calibration line to resolve the water content on the Martian olivines and find a potential location of new water within the defects.

Two 1 inch indium mounts were prepared with olivine plus glass standards and paired Martian nakhlite samples (Yamato 593, 802, 749, Lafayette and Nakhla) to confirm this source of Martian ground water. Work was conducted with Dr Johan Villeneuve and Dr Laurette Piani on the Cameca IMS 1270 E7 ion probe at CRPG, Nancy. The new obtained/formed standards provided calibration to measurements of water contents (H₂O%) within the Martian olivines and when combined with standards from CRPG δD values were roughly constrained. Owing to the unique surfaces of each Martian altered olivine it was impossible to confirm pre analyses if defects hosting water would be present in the outer olivine surfaces. Results show a location where an enriched δD was present, further investigations such as Transmission Electron Microscopy (TEM) are required to confirm this.

20-EPN2-067: Hydrogen isotope compositions of matrices in unequilibrated ordinary chondrites

Visit by Helen Grant, University of Manchester (UK) to TA2.9 Ion Probe Facility (IPF), CRPG (France).
Dates of visit: 10-21 October 2022

Report Summary: One way to study the origin of water and other volatiles which accreted onto rocky planets such as Earth during the formation of the Solar System is to study meteorites that fall from asteroids and other planetary bodies. Hydrogen isotope ratios within meteorites can be used as a tracer for the source of a body’s water, and to an extent spatial and temporal information about the formation of parent bodies. 

Previously, we measured the D/H ratios of bulk powders of a wide range of unequilibrated ordinary chondrites (UOCs), and found wide variations which did not fit into current H-distribution models. Using SIMS, we measured the H, D, C, and Si contents of the fine-grained matrix of 13 of these previously studied UOCs (only falls) ranging from types 3.00 – 3.9. Preliminary results confirm the wide previously observed spread of D/H ratios between samples, including high elevations in a handful of UOCs. C/H ratios will be used to determine the D contribution within samples specific to water, however initial observations confirm contributions from both hydrated and organic components. The results from this visit will be combined with other in-situ studies carried out at the home institution to determine exactly what phases are hosting this highly D-rich material, and how these chondrites affect models of water transport in the early Solar System.

Read the full scientific report, with kind permision from Helen Grant.

20-EPN-031: Investigating volatiles in the early Solar System through analysis of halogens in chondrules

Visit by Edward Baker, University of Manchester (UK) to TA2.9 Ion Probe Facility (IPF), CRPG (France).
Dates of visit: 13-17 December 2021

Report Summary: We have measured the concentration of halogens in the glasses of chondrules from enstatite chondrites. There is a clear correlation between Chlorine and Bromine abundances, but no clear relationship between Cl or Br and F. Iodine was not measured. In the main S is well correlated with Cl: this trend may have been modified by unintended analysis of micron scale blebs on sulphide.  Halogen profiles have been taken across a number of suitable target chondrules, for diffusion modelling, which will be presented and published in due course. The array of data for F/Cl is sub-chondritic while the Br/Cl array is super-chondritic.

Evaporation and condensation may play important roles in controlling halogen behaviour, along with partitioning between other significant reservoirs in chondrites because fluorine is likely to be compatible in a number of silicate minerals. More will be known after diffusion modelling and after the experimental partition coefficients have been determined. 

Read the full scientific report, with kind permision from Edward Baker and Rhian Jones.

20-EPN-034: Calibration of the Al-in-olivine thermometer: Insight into the thermal history of type II chondrules

Visit by Thomas van Gerve and Kat Shepherd, KU Leuven (Belgium) to TA2.9 Ion Probe Facility (IPF), CRPG (France).
Dates of visit: 18-22 October 2021

Report Summary: Chondrites are the most primitive agglomerates formed in the solar system. In this project, we want to develop a thermometer based on Al-in-olivine/spinel equilibrium to calculate the temperature of formation of chondrites. or this project, we have performed a large number of new low- to high-pressure (1 atm – 10 GPa) experiments relevant to chondrule formation at the KU Leuven.

Experiments were run at high temperature (1200-1800°C), under variable oxygen fugacity conditions (IW+1 to IW+5, IW = iron-wustite). From 18-22 October 2021, Thomas van Gerve and Kat Shepherd (KU Leuven) worked with the Cameca IMS 1270 E7 ion probe at CRPG, Nancy, under the supervision of Dr. Johan Villeneuve and M. Nordine Bouden. We have measured the following masses: ¹²C, ¹⁶O¹H, ¹⁸O, ¹⁹F, ²⁷Al, ³⁰Si, ³²S and ³⁵Cl in olivine, glass and glass inclusions. During our analytical session, we measured ~ 150 points in olivine and glass in addition to the standards. Results are extremely reproducible and show a trend of slightly increasing Al content in olivine as a function of the Fo content (molar Mg/(Mg+Fe)) of olivine. Using our new SIMS results, we are in the process of developing a thermodynamically rooted model taking into account major components in spinel and olivine.

Read the full scientific report, with kind permision by Thoma van Gerve and Kat Shepherd.