Crust-atmosphere coupling and CO 2 sequestration on Mars Adrienne Macartney 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?

Carbonation Triangle Exposed ultra-basic rocks CO 2 Water

Exposed ultra-basic rocks CO 2 Water Heat, 180°C optimal Hyper - Carbonation Square

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) Amazonian Noachian - Hesperian SNC Mars Meteorites Shergottites Nakhlites Chassignites

Joys of Norwegian fieldwork in January Punctuated hyper-carbonation Micro-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 Time AmazonianNoachian - Hesperian Conceptual graph of carbonation dynamics (no units) Blue = micro-carbonation Red = punctuated hyper-carbonation

Lafayette Mars meteorite data ALH 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 Team Pfeiffer 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