The Open UniversitySkip to content

Constraining the formation conditions of the ancient martian ALH 84001 carbonates

Tomkinson, Tim Oscar Roland (2013). Constraining the formation conditions of the ancient martian ALH 84001 carbonates. PhD thesis The Open University.

Full text available as:
PDF (Version of Record) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (40MB) | Preview
Google Scholar: Look up in Google Scholar


The martian meteorite ALH 84001 contains carbonates that provide information about the past aqueous conditions on Mars 3.9 Ga, and have been suggested to display signatures of martian organics. Determining the conditions under which the carbonates formed is crucial for addressing whether there was once life on Mars and the history of martian hydrosphere and atmosphere. This study has combined new sample preparation techniques with fresh isotopic analyses of ALH 84001 carbonates and analogue materials, geochemical modelling and the testing of future equipment (WatSen) suitable for carbonate detection on Mars. The results from these lnvestigations have provided quantitative constraints on the formation environment for the ALH 84001 carbonates and an instrument capable of detecting carbonates on Mars. The microscale carbon and oxygen analyses of ALH 84001 carbonates provide the first combined transient study across the carbonates with δ13C and δ18O values correlated ,with chemical compositions. The δ13C values range from -18.6% to +23.2% extending and lowering the previous ion microprobe δ13C range found and suggests that reduced carbon is present in the carbonates. This component exists as either macromolecular carbon introduced through subsequent alteration, terrestrial contamination or martian organics. The δ18O range -0.1% +27.1% is consistent with previous authors and displays a clear correlation with δ18O enrichment with distance from the carbonates core to edge. An 18.6% range in δ18O values was measured across analogue carbonates similar in size, shape and chemical variation which formed in a hydrothermal environment

Item Type: Thesis (PhD)
Copyright Holders: 2013 The Author
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
Item ID: 61122
Depositing User: ORO Import
Date Deposited: 13 May 2019 09:40
Last Modified: 15 May 2019 18:00
Share this page:

Download history for this item

These details should be considered as only a guide to the number of downloads performed manually. Algorithmic methods have been applied in an attempt to remove automated downloads from the displayed statistics but no guarantee can be made as to the accuracy of the figures.

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU