Mars Noble Gas Experiments 30-Day Pilot Experiment Status Mark Bullock Jan 23, 2015

Incubation of Mars-analog minerals in H2O Minerals: Olivine, pyroxene, and feldspar separately and in mixtures. Crushed and seived to 1-2 mm. 50 g of mineral + 100 ml of carbonated, de-oxygenated DI water in each reaction vessel. Mars synthetic gas humidified and circulated through reaction vessels. 18 full reaction vessels + 13 control vessels. Incubation began at 4:00 pm PST 16 Jan 2015.

Mineral Mixtures Olivine: Forsterite Pyroxene: Augite Feldspar: Andesine NB: The use of forsterite means that the olivine is too Fe- poor to represent Mars. A – Olivine B – Pyroxene C – Feldspar D – 50% Olivine + 50% Feldspar E – 50% Pyroxene + 50% Feldspar F – 50% Olivine + 25% Pyroxene + 25% Feldspar

Mars gas mixture We specified: GC Analysis by supplier AirGas yielded: Kr 30.0 ppm Xe 8.0 ppm Remainder CO2 GC Analysis by supplier AirGas yielded: Ar 2.084% ± 2% Kr 34.90 ± 5% Xe 8.564 ± 5%

Layout of Reaction Vessels in Glovebox

Reaction Vessels Teflon vessels, seals, and fittings 250 ml volume Each contains: 50 g of minerals 100 ml of DI water Flow through of Mars gas Temperature controlled at 38°C ± 1°C 3 reaction vessels for each of 6 mineral mixtures (18 total) Additional set of 6 vessels with no fluid (controls) Set of 6 vessels with flow through of Earth air instead of Mars gas (controls)

Reaction vessels in glovebox Left: Daisy-chained reaction vessels in the glovebox. Some gas plumbing can be seen in the upper left. Lower center is the aquarium pump that drives the Earth-air gas circuit for the control vessels. Below: Mark Bullock and Carrie Chavez in front of the complete stack of 3 gloveboxes. We are using only the middle one. Missing: Heather Smith, who helped us all week but wasn’t at the lab during the final photo session.

Temperature and gas flow control Right: CO2 gas in and out of the glovebox, and Mars gas trickle out. Below: Flow gauge with recirculating heater/cooler in the background.

Experiment Status Jan 23, 2015 Mars analog minerals will continue to be incubated until 13 Feb. Fluids will be withdrawn and dissolved ions quantified with atomic absorption spectroscopy Minerals will be dried and on Feb 16 shipped to: Susanne at the Open University John Bridges at Leicester University Michael Miller at SwRI, San Antonio Tim Swindle at the University of Arizona

Composition of the runs - mineral data from Bullock et al. (2004) Augite Andesine Forsterite Pyrite Ilmenite 50Ol:25Fsp:25Pyx 50Ol: 50Pyx 50 Ol: 50 Plag SiO2 52.1 63.4 41.8 49.8 47.0 52.6 Al2O3 2.4 21.6 6.0 1.2 10.8 TiO2 0.6 53.9 0.15 0.3 FeO 9.5 0.1 7.1 46.4 5.9 8.3 3.6 CaO 19.1 2.3 5.4 9.6 MgO 14.6 56.7 32.0 35.7 28.4 Na2O 8.6 2.2 0.2 4.3 K2O 3.8 1.0 1.9 P2O5 Cl S 53.3

Comparing to Mars: 50Ol:25Fsp:25Pyx 50Ol: 50Pyx 50 Ol: 50 Plag Portage Soil1 Lafayette2 Dhofar 3873 Shergotty4 SiO2 49.8 47.0 52.6 42.88 46.9 49.88 51.36 Al2O3 6.0 1.2 10.8 9.43 2.74 10.08 7.06 TiO2 0.15 0.3 1.19 0.42 0.98 0.87 FeO 5.9 8.3 3.6 19.19 21.6 19.94 19.41 CaO 5.4 9.6 7.28 13.4 10.32 10 MgO 32.0 35.7 28.4 8.69 12.9 5.66 9.28 Na2O 2.2 0.2 4.3 2.72 0.4 1.98 1.29 K2O 1.0 1.9 0.49 0.11 0.17 0.164 P2O5 0.94 0.45 0.7 0.8 Cl 0.69 S 5.45 0.04 1: Gellert et al. (2013), 2: Treiman (2005), 3: Ikeda et al. (2003), 4: Dreibus et al. (1982)

What analytics are... neccessary? sufficient? desireable? Remember, this is a test run only....

Analytics.... We need from the first 6 vessels : SEM Fluids Noble gases, from all the above vessels and the last olivine in fluid vessel We might also want: all the above from the just wet vessels microprobe element maps in depth mineral analytics, if we see some evidence for secondary minerals The big question: Do we do mineralogy sequentially: SEM first, then assess the situation?

Who wants how much sample?

Who wants how much sample? What Who For How much Mineralogy Michael SEM John Susanne microprobe? ? Noble gases Tim Susanne/Simon Laser ablation? Fluids Mark anything else?

What do we need for LPSC?

For LPSC.... We need results: Microprobe data of the mineral grains that went in to ensure we have the compositions as published by Bullock et al. (2004) SEM to assess the extent of alteration, potential element mobilization Fluids to assess the dissolution rate and estimate what was dissolved Noble gases as our first main result and also to demonstrate that no fractionation occurrs We need on theoretical grounds: models of the alteration We need for the presentation: 'pretty pictures' of the set up and our specific experiment images of the product just after opening the vessels images of the grains after the experiment (SEM) graphs with data and models

For the next run...

For the next run... We need a wide range of decisions: Chemsitry of the rock: Do we want to match the Fe contents? And how? Mineralogy: Do we want sulphide, any other trace minerals? More mineralogy: Do we want to match apatite content and assess P in the solution, since P is one of the limiting elements for biology? How long will the run be? Timing and other things: Run start in April Duration one year - or shorter? Tempersture 35 °C Analytics etc: But that is to be discussed later...