Crust-atmosphere coupling and CO2 sequestration on MarsAdrienne Macartney (a.macartney.1@research.gla.ac.uk)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

Summary1. 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