Presented by Ryan Moyé

Deuterium + Hydrogen

Where are we? What are we looking at? km ~3.6 Ga

Drill Hole D/H Analysis Mars Science Laboratory (MSL) – Curiosity Rover instruments: Sample Analysis at Mars (SAM): Quadrupole mass spectrometer Tunable laser spectrometer (TLS) 6-column gas chromatograph Chemistry and Mineralogy (CheMin) instruments *Revealed a smectite clay mineral, an amorphous component, and basaltic minerals  isochemical alteration  authigenic Smectite Mahaffy et al., 2012 ; Mahaffy et al.,

Clays on Mars: Smectite Montmorillonite

Reservoir Models Single Reservoir Models: Entire near surface H20 reservoir is exposed to atmospheric loss Equation: Compared to Martian meteorites (assuming a continuous D/H evolutionary timeline, allowing for constraint on near-surface Hesperian age water. Multiple Reservoir Models: There is an exposed surface reservoir and an inaccessible reservoir, most likely in the form of ice caps, where R = amount of water, I = D/H ratio, and f = fractionation factor

Evolved Gas Analysis (EGA) – H20

TLS – High Temperature Water Evolution

TLS - Relative D/H (to SMOW) vs. Temperature

Reservoir Models Single Reservoir Models: Entire near surface H20 reservoir is exposed to atmospheric loss Equation: Compared to Martian meteorites (assuming a continuous D/H evolutionary timeline, allowing for constraint on near-surface Hesperian age water., where R = amount of water, I = D/H ratio, and f = fractionation factor

Conclusions Assuming a fractionation factor between (diffusion limit), amount of water lost since Yellowknife Bay clay minerals formed would be ~1-1.5 times the current surface/near-surface water reservoirs (including polar ice caps). Current reservoirs are ~50m, so water equivalent global layer (GEL) at the time of formation of Cumberland mudstone would be at least m.