Aqueous alteration in C2-ung Bells through the analysis of carbonates – Does a CR origin ring true?

· by · in , , , ,

L. J. Riches, M. D. Suttle, I. A. Franchi, X. Zhao, M. M. Grady

MAPS, Version of Record online: 20 April 2026

LINK

“Bells is an ungrouped carbonaceous chondrite that has in recent years been proposed as a CR-an. This link to CR chondrites has previously been identified through the analysis of anhydrous silicates, for example, oxygen isotopic compositions of olivine (Marrocchi et al., 2023). In this study, the aqueous alteration extent of Bells has been analyzed through the use of carbonate minerals to see whether Bells’ aqueous history supports a CR origin. The carbonates identified were calcite grains that had O-isotope compositions showing a single generation trend ranging from δ18O = +20.7 to +40.3‰, δ17O = +6.9 to +23.4‰ and Δ17O = −4.1 to +2.4. These are isotopically similar values to carbonates found in other CR-an meteorite Al Rais (δ18O = +28.8 to +34.8‰ Jilly-Rehak et al., 2018). Oxygen isotope compositions plot along a mass-independent slope of 0.75 ± 0.12, which indicates that isotopic evolution is controlled primarily by mixing of fluid and rock reservoirs. Starting temperatures for calcite precipitation are estimated to be ~14°C. These observations here help support a potential reclassification of Bells as a CR-an meteorite.”

Related posts (automatically generated):

  1. From whom Bells tolls: Reclassifying Bells among CR chondrites and implications for the formation conditions of CR parent bodies
  2. Aqueous alteration in the C2-ung Tarda meteorite: in situ isotopic evidence from dolomite and magnetite
  3. Detection Of Incipient Aqueous Alteration In Carbonaceous ChondritesOPEN ACCESS 
  4. LOW-TEMPERATURE AQUEOUS ALTERATION ON THE CR CHONDRITE PARENT BODY: IMPLICATIONS FROM IN SITU OXYGEN-ISOTOPE ANALYSES
  5. Fluid history in the ungrouped C2 Essebi meteorite parent bodyOPEN ACCESS 
  6. Clumped isotope and Δ17O measurements of carbonates in CM carbonaceous chondrites: new insights into parent body thermal and fluid evolutionOPEN ACCESS 
  7. Noble gases in CM carbonaceous chondrites: Effect of parent body aqueous and thermal alteration and cosmic ray exposure agesOPEN ACCESS 
  8. Iron XANES measurements of carbonates and phyllosilicates in CM chondrites: A record of redox conditions during aqueous alterationOPEN ACCESS 
  9. SIMS matrix effects in oxygen isotope analysis of olivine and pyroxene: Application to Acfer 094 chondrite chondrules and reconsideration of the primitive chondrule minerals (PCM) line
  10. Accretion of the anomalous CR2 chondrite Northwest Africa 14674: Implications for the complexities of the CR parent bodies
Tags: , , , , , , , , , , , ,