Crust-atmosphere coupling and CO2 sequestration on MarsAdrienne Macartney ([email protected])
School of Geographical & Earth Sciences
Cold icy Mars?
Warm wet Mars?
Modern Mars
What caused the loss of the Mars atmosphere and hydrosphere?
• Geology and engineering cross discipline project building an ultra-sonic rock polishing tool to discover insitu carbonation evidence on Mars.
• Investigating the role and scale of mineral carbonation via terrestrial analogues (ophiolites), chambered experiments and meteorite analysis.
Fluctuating states of equilibrium?
CarbonationTriangle
Exposed ultra-basic rocks
CO2
Water
Exposed ultra-basic rocks
CO2
Water
Heat, 180°C optimal
Hyper - CarbonationSquare
Joys of Norwegian fieldwork in January
Micro-carbonation
• Wide geographic scale
• Low water:rock ratio
• Relatively small amounts of sequestration
• ‘SNC’ style carbonate evidence
Global carbon
sequestration
Time
Conceptual graph of carbonation dynamics (no units)
AmazonianNoachian - Hesperian
SNC Mars Meteorites
ShergottitesNakhlites
Chassignites
Joys of Norwegian fieldwork in January
Punctuated hyper-carbonationMicro-carbonation
• Wide geographic scale
• Low water:rock ratio
• Relatively small amounts of sequestration
• ‘SNC’ style carbonate evidence
• Highly geographically localised
• High water:rock ratio required
• Significant sequestration
• Deep sub-surface, density change, mineralogical evidence
Global carbon
sequestration
TimeAmazonianNoachian - Hesperian
Conceptual graph of carbonation dynamics (no units)
Blue = micro-carbonationRed = punctuated hyper-carbonation
Lafayette Mars meteorite data
• ALH 84001 studies to follow shortly
• Comparison with terrestrial Ophiolite weathering and replacement sequences (LOC and Oman)
Testing micro-carbonation 1
Joys of Norwegian fieldwork in January
Testing micro-carbonation 2
Joys of fieldwork in January
Leka possesses the full ‘textbook’ sequence of ophiolite strata
Testing micro-carbonation 2
The Leka Ophiolite Complex (LOC), Norway
• Formed ~497Ma +/- 2Ma, part of the Skei group obducted in the Caledonian orogeny
• Analogous to Mars mineral carbon sequestration?
• Is the water:rock ratio analogous?
Testing micro-carbonation 2
Initial light microscopy:
• Extensive serpentinisation and antigorite replacement
• Numerous opaque minerals (chromite, magnetite)
• Minor carbonates in veins
Testing micro-carbonation 2
Prototyping an improved Mars rover tool
RAT - Rock Abrasion Tool
MOUSE – Micro-Optic Ultra-Sonic Exfoliator
Supported by: Space Glasgow, University of Glasgow Ultra-Sonic Planetary Drilling TeamPfeiffer
Testing micro-carbonation 3
Summary
1. Water on the Mars surface requires an atmosphere many bars higher than present
2. Mineral carbon sequestration is a robust partial answer, supported by terrestrial analogues - Large scale surface micro-carbonation - Localised punctuated hyper-carbonation (CARBFIX analogue)
3. Comparative microscopic analysis between ophiolites and SNC meteorites may provide insight into important fluid and carbon sequestration processes on the Martian crust-
atmosphere
4. Developing the MOUSE, a rover prototype ultra-sonic polisher to aid locating insitu evidence of carbon sequestration
