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

2. 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 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.

3. 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

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

5. Layout of Reaction Vessels in Glovebox

6. 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)

7. 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.

8. 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.

9. 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Fluids will be withdrawn and dissolved ions quantified with atomic absorption spectroscopy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

10. 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

11. 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)

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

13. 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?

14. Who wants how much sample?

15. 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?

16. What do we need for LPSC?

17. 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

18. For the next run...

19. 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...