Analysis of lunar highland regolith samples from Apollo 16 drive ...

Geological Society of America 2008Analysis of lunar highland regolithsamples from Apollo 16 drive core64001/2 and lunar regolith simulants –an expanding comparative databaseChristian M. Schrader and Doug RickmanMarshall Space Flight Center, Huntsville, ALDouglas StoeserUnited States Geological Survey, Denver, COSusan Wentworth and Dave S. McKayJohnson Space Center, Houston, TXPieter Botha, Alan R. Butcher, Hanna E. Horsch, Aukje Benedictus, andPaul GottliebIntellection in Denver, CO and Brisbane, QLD

Outline• Background of the lunar regolithsimulant effort• Apollo site and sample selection• Results of QEMSCAN ® modalanalysis of lunar material– change in major mineralmodal% with size fraction– comparison of major/traceminerals in sieved vs. thinsection samples9/15/2008 BAE Systems, Marshall SpaceFlight Center2

Outline, cont.• Results of analysis of simulantsvs. Apollo samples• Future, ongoing, and parallel work9/15/2008 BAE Systems, Marshall SpaceFlight Center3

In support of a future lunar outpost...• This work is part of a larger effort to compile an internally consistentdatabase on lunar regolith (Apollo samples) and lunar regolithsimulants.– Characterize existing lunar regolith and simulants in terms of• Particle type• Particle size distribution• Particle shape distribution• Bulk density• Other compositional characteristics– Evaluate regolith simulants (Figure of Merit) by above properties bycomparison to lunar regolith (Apollo sample)9/15/2008 BAE Systems, Marshall SpaceFlight Center4

Apollo 16 siteLMStation 4:64001/640029/15/2008 BAE Systems, Marshall SpaceFlight Center5

Station 4 samplesgeochemical data from Korotev (1982) and Korotev et al. (1984)64002(Houck, 1982)One thin-section64002,6019: 5.0 – 8.0 cm3.0 4.0 5.0 6.0 7.00100040 50 60 70 80 90 100 110Eight sieved samples64002,262: 5.0 – 5.5 cm64001(Basu & McKay, 1984)One thin-section64001,6031: 50.0 – 53.1 cmdepth, centimeters20304050%FeO0000Is/FeOEight sieved samples64001,374: 52.0 – 52.5 cm60070Apollo 16 core 64001/640020Apollo 16 core 64001/640029/15/2008 BAE Systems, Marshall SpaceFlight Center6

Modal analysis of sieved grain mounts64002,262 sieved fractions64001,374 sieved fractions7070modal%6050403053504929250-500 μm90-150 μm45-75 μm

Change in modal% by size fraction: 64002,2622.564002, 262fraction/integrated2.01.51.00.5250-500 μm90-150 μm45-75 μm

Change in modal% by size fraction: 64001,3742.564001, 374fraction/integrated2.01.51.00.5250-500 μm90-150 μm45-75 μm

Modal analysis: thin sections versus integratedbulk grain mountsmodal%60504030204440433664002, 6019 (TS)64002, 262 (GM)64001, 6031 (TS)64001, 374 (GM)46444641• Minerals report as higherin thin section than incorresponding integratedgrain mounts.– Edge effects/mixedphases in thin sectionsreport as minerals?– Real effect from missingfractions in grain mounts?1003 3 3 31 1 1 1Plagioclase Pyroxene Olivine Glass– Sampling error fromsieving?• Glass shows less regularpattern.9/15/2008 BAE Systems, Marshall SpaceFlight Center10

Modal analysis: thin sections versus integratedbulk grain mounts0.40• Trace Minerals:modal%0.350.300.250.200.1564002, 6019 (TS)64002, 262 (GM)64001, 6031 (TS)64001, 374 (GM)– Given, the very lowamounts of some traceminerals (

Unclassified material in QEMSCAN ® modal analysis40064002,26264001,374350 300 250 200 150 100Middle of size bin (μm)500302520151050unclassified (modal%)The modal% of unclassifiedmaterial:– ranges from ~5-24% in anyone analysis;– tends to increase as sizefraction decreases in grainmounts;Thin sections64002,6019: 6.6% unclassified64001,6031: 6.4% unclassifiedIntegrated grain mounts64002,262: 8.4% unclassified64001,374: 16.9% unclassified9/15/2008 BAE Systems, Marshall SpaceFlight Center– is higher in integrated grainmounts than in thin sections• (is more materialmisclassified due to edgeeffects and phase mixing?)• (is this from another,unknown effect?)12

Lunar simulants: Mare and HighlandsNU-LHT-1M lunarhighlands simulantJSC-1A lunar maresimulant9/15/2008 BAE Systems, Marshall SpaceFlight Center13

Overview: Major mineral modal comparisonbetween simulants and 64001/64002modal%70605040302010067544445364001/2 TS Avg.NU-LHT-2MNU-LHT-1M45 44OB-1251310 10 1035 5170605040302010053524439 383564001/2 TS Avg.JSC-1JSC-1AJSC-1AFFJS-1MLS-1 352216171412128315145342919178Plagioclase Pyroxene Olivine GlassPlagioclase Pyroxene Olivine GlassHighland simulantsMare simulantsWe are incorporating particle type data (e.g., the presence ofagglutinates) and phase chemistry into these comparisons.9/15/2008 BAE Systems, Marshall SpaceFlight Center14

Overview: Trace mineral modal comparisonbetween simulants and 64001/64002modal%0.450.400.350.300.250.2064001/2 TS Avg.NU-LHT-2MNU-LHT-1MOB-10.450.400.350.300.250.2064001/2 TS Avg.JSC-1JSC-1AJSC-1AFFJS-1MLS-10.150.150.100.100.050.050.000.00Ilmenite Ap/Whit. Native Fe Spinel SulfidesIlmenite Ap/Whit. Native Fe Spinel SulfidesHighland simulantsMare simulantsWe are incorporating particle type data (e.g., the presence ofagglutinates) and phase chemistry into these comparisons.9/15/2008 BAE Systems, Marshall SpaceFlight Center15

Further and ongoing work• Continue to analyze Apollo samples by total phasemodal%.• Incorporate particle type modal analysis by determiningwhich phases are present in lithics, breccias,agglutinates, etc.• Incorporate phase chemistry.• Analyze simulants by these same techniques forcomparison by Figure of Merit algorithms.9/15/2008 BAE Systems, Marshall SpaceFlight Center16

Parallel workCharacterizing particle size and shapedistributions and bulk densities of lunarregolith and simulants for comparison byFoM.9/15/2008 BAE Systems, Marshall SpaceFlight Center17

ReferencesBasu, A. and Mckay, D.S., “Petrologic Profile of Apollo 16 Regolith at Station 4”,Proceedings of the 15th Lunar and Planetary Science Conference, Part 1, Journal ofGeophysical Research, Vol. 89, Supplement, 1984, pp. C133-C142.Houck, K.J., “Modal Petrology of Six Soils from Apollo 16 Double Drive Tube 64002”,Proceedings of the 13th Lunar and Planetary Science Conference, Part 1, Journal ofGeophysical Research, Vol. 87, Supplement, 1982b, pp. A210-A220.Korotev, R.L., “Comparative Geochemistry of Apollo 16 Surface Soils and Samplesfrom Cores 64002 and 60002 through 60007”, Proceedings of the 13th Lunar andPlanetary Science Conference, Part 1, Journal of Geophysical Research, Vol.. 87,Supplement, 1982, pp. A269-A278.Korotev, R.L., Morris, R.V., and Lauer, H.V., Jr., “Stratigraphy and Geochemistry of theStone Mountain Core (64001/2)”, Proceedings of the 15th Lunar and PlanetaryScience Conference, Part 1, Journal of Geophysical Research, Vol. 89, Supplement,1984, pp. C143-C160.9/15/2008 BAE Systems, Marshall SpaceFlight Center18