Analysis of pathways for volatile-bearing mineral formation in carbonaceous chondrites using thermodynamic simulations
type: CreativeWork
description: Low temperature minerals in carbonaceous chondrites record volatile processes in the solar system. These processes could occur via liquid-solid or gas-solid reactions; however, few studies have considered gases. A Gibbs free energy minimization approach was used to investigate the formation of the Tagish Lake meteorite's low temperature matrix including gases and liquid water, with starting compositions of low O and high O determined from its bulk composition. The high O model predicts phyllosilicate formation at <500 Degrees C, accounting for up to 24 mol% of solids and showing a similar compositional trend to observations of Tagish Lake's carbonate-rich lithology. Carbonates reached a maximum abundance of 50 mol% of solids at the lowest simulated temperature (0 Degrees C), being the most abundant group of minerals, excluding water. The low O model also formed phyllosilicates at <500 Degrees C, reaching up to ~18 mol% of solids, however carbonates were negligible. The low O phyllosilicate compositions more closely mirror the Tagish Lake's carbonate-poor lithology. The low O composition also predicts the coexistence olivine and abundant phyllosilicate for temperatures <150 Degrees C. These models indicate the importance of O in carbonaceous chondrite alteration and confirm that high and low temperature minerals could coexist in carbonaceous chondrites in a system open to gas within the parent body. Also, this model provides a method of quantifying volatile loss due to heating on an asteroid.
abstract: Low temperature minerals in carbonaceous chondrites record volatile processes in the solar system. These processes could occur via liquid-solid or gas-solid reactions; however, few studies have considered gases. A Gibbs free energy minimization approach was used to investigate the formation of the Tagish Lake meteorite's low temperature matrix including gases and liquid water, with starting compositions of low O and high O determined from its bulk composition. The high O model predicts phyllosilicate formation at <500 Degrees C, accounting for up to 24 mol% of solids and showing a similar compositional trend to observations of Tagish Lake's carbonate-rich lithology. Carbonates reached a maximum abundance of 50 mol% of solids at the lowest simulated temperature (0 Degrees C), being the most abundant group of minerals, excluding water. The low O model also formed phyllosilicates at <500 Degrees C, reaching up to ~18 mol% of solids, however carbonates were negligible. The low O phyllosilicate compositions more closely mirror the Tagish Lake's carbonate-poor lithology. The low O composition also predicts the coexistence olivine and abundant phyllosilicate for temperatures <150 Degrees C. These models indicate the importance of O in carbonaceous chondrite alteration and confirm that high and low temperature minerals could coexist in carbonaceous chondrites in a system open to gas within the parent body. Also, this model provides a method of quantifying volatile loss due to heating on an asteroid.
author: Baile, Riley
language: en_AU
date published: 2026
date modified: 2026-07-24T00:54:30Z
provider: Australian National University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Australian National University

PropertyValue
property ID: Handle
value: https://hdl.handle.net/1885/733808735