TEGA Oven 0 High Temperature Run

Thermal and Evolved Gas Analysis of

Wicked Witch

Doug Ming and the TEGA Team

Wicked Witch

Wicked Witch was a subsurface sample acquired by the RA scoop from the Snow White Trench on Sol 64

Wicked Witch Sample

Wicked Witch H2O Releases

Baby Bear H2O Releases

Candidate Water-Bearing Phases

700-1000°C

Dehydroxylationof Al-OH from octahedral positions

Montmorillonite

Beidellite

Many others

High Temp Endo and Exothemicreactions

Dehydroxylationof Trans-vacant Al-OH in Montmorillonite and subsequent formation of enstatite

Wicked Witch CO2Release

Baby Bear CO2Release

Candidate CO2-Bearing Phases

350-550°C

Pyrolysis of organic molecules

Decomposition of Fe-carbonate

450-700°C

Pyrolysis of organic molecules (e.g., kerogen-like)

Decomposition of Fe-, Mg-and/or Fe-Mg-Ca mixed carbonates

700-1000°C

Decomposition of Ca-carbonate

Magnesite

Siderite

Calcite

Wicked Witch Evolved Gas Summary

CO2evolved over a wide range

325-600°C

700-1000°C

High temperature water release

Very small amount released

600-1000°C

No Mass 64 or 70 observed

No organic fragments observed in run

Organics may have been combusted if they were present

Or there are no organics in the surface soil

Wicked Witch Thermal Analysis Summary

“Major”Endotherms

750-800°C

Candidate

Calcite (based upon CO2evolution)

840-880°C

Candidates

Al-OH dehydrolylation(based upon small amount of water release)