Aqueous Alteration and Hydrogen Generation on Parent Bodies of Unequlibrated Ordinary Chondrites: Thermodynamic Modeling for the Semarkona Composition

Hydrogen Chloride as a Source of Acid Fluids in Parent Bodies of Chondrites

Introduction: Chondrites reveal signs of aqueous alteration on their parent bodies [1-4] that occurred under a broad range of pH. The dominance of secondary Mg-phyllosilicates (saponite, serpentine, chlorite) in pervasively altered CI and CM chondrites [1-4] suggests alkaline conditions during deposition [5,6]. However, localized occurrences of phosphates and carbonates in CM carbonaceous chond...

Oxygen isotopes in R-chondrite magnetite and olivine: Links between R chondrites and ordinary chondrites

Ion-microprobe studies yield DO (5dO 2 0.52 z dO) values in magnetite from the Rumurti chondrite (RC) PCA91241 (which is paired with PCA91002) of 13.1 to 13.9‰, slightly higher than that in O from whole-rock R samples. Despite DO values in whole-rock RCs that are much (by ca. 1.6‰) higher than in whole-rock LL chondrites, the DO in R magnetite is much lower (by ca. 2‰) than the values (14 to 17...

Thermodynamic constraints on fayalite formation on parent bodies of chondrites

available online at http://meteoritics.org Thermodynamic constraints on fayalite formation on parent bodies of chondrites Mikhail Yu. ZOLOTOV1*, Mikhail V. MIRONENKO2, and Everett L. SHOCK1, 3 1School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287–1404, USA 2Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Kosygin Street ...

PSRD: Chondritic Asteroids: When Did Aqueous Alteration Happen?

Using a synthesized fayalite (Fe2SiO4) standard for improved 53Mn-53Cr radiometric age dating, Patricia Doyle (previously at the University of Hawai‘i and now at the University of Cape Town, South Africa) and coauthors from Hawai‘i, the National Astronomical Observatory of Japan, University of Chicago, and Lawrence Livermore National Laboratory in California, analyzed aqueously formed fayalite ...

Early Alteration of Matrices in Parent Bodies of Ci/cm Carbonaceous Chondrites: Kinetic-thermodynamic Modeling