Effects of Impact and Heating on the Properties of Clays on Mars Patricia Gavin V. Chevrier, K. Ninagawa, S. Hasegawa

Effects of Impact and Effects of Impact and Heating on the Properties of Heating on the Properties of

Clays on MarsClays on Mars

Patricia Gavin Patricia Gavin

V. Chevrier, K. Ninagawa, S. HasegawaV. Chevrier, K. Ninagawa, S. Hasegawa

http://www.jaxa.jp/index_e.html

IntroductionIntroduction Clays surrounded by Clays surrounded by

lava flows and in crater lava flows and in crater ejectaejecta Heat and shock effectsHeat and shock effects

Possible effects on claysPossible effects on clays Loss of waterLoss of water Structural changeStructural change New phases formedNew phases formed

ExperimentsExperiments Heat in ovenHeat in oven Impact in light gas gunImpact in light gas gun

Poulet et al., 2005 Mangold et al., 2007

Heating experimentsHeating experiments 2 relevant clays2 relevant clays

Montmorillonite (Ca, Al clay)Montmorillonite (Ca, Al clay) Nontronite (FeNontronite (Fe3+3+ clay) clay)

Thermal treatment in tube ovenThermal treatment in tube oven 350350ooC < T < 1150C < T < 1150ooCC 4 hr < t < 24 hr4 hr < t < 24 hr Air and COAir and CO22 atmosphere atmosphere

AnalysisAnalysis XRDXRD ESEMESEM Reflectance spectraReflectance spectra

Color ChangesColor Changes

Nontronite

Untreated Heated

Montmorillonite

Nontronite: Low temperatureNontronite: Low temperature

T < 750T < 750ooC: C: Loss of Loss of interlayer peakinterlayer peak

Collapse of Collapse of structurestructure

Loss of waterLoss of water ~25% mass~25% mass

UntreatedAir, T = 630oCCO2, T = 475oC

Counts/secCounts/sec

0

10

20

30

40

50

60

70

80

90

100

1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6Wavelength (m)

% R

efl

ec

tan

ce

Nontronite: Low TemperatureNontronite: Low Temperature

Untreated

T = 475oC

T = 630oC

OH band Water band

Metal - OH band

Nontronite: Intermediate Nontronite: Intermediate TemperatureTemperature

800 < T < 800 < T < 10001000ooC: complex C: complex mixture of mixture of secondary secondary phasesphases

Large peaks = Large peaks = nanocrystalline nanocrystalline phasesphases

Solid-solid Solid-solid transformationtransformation no meltingno melting

Counts/sec

Offset by 100 units

Nontronite: High temperatureNontronite: High temperature


T > 1100oC: melting and crystallization of high temperature phases sillimanite hematite cristobalite glass

0

10

20

30

40

50

60

70

80

90

100

1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6Wavelength (m)

% R

efl

ec

tan

ce

Nontronite: Intermediate Nontronite: Intermediate and High Temperatureand High Temperature

Untreated

T = 1130oC

T = 975oC

T = 810oC

Montmorillonite: Low Montmorillonite: Low TemperatureTemperature

T < 750T < 750ooC: C: most peaks most peaks still intactstill intact

More resistant More resistant to thermal to thermal alterationalteration

QuartzQuartz AlbiteAlbite

Untreated

T = 630oC

Offset by 400 units


Montmorillonite: High Montmorillonite: High TemperatureTemperature

T > 1100T > 1100ooC: C: formation of high formation of high temperature temperature phasesphases silimanitesilimanite cristobalitecristobalite micamica amorphous amorphous

glassglass


0

10

20

30

40

50

60

70

80

90

100

1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6Wavelength (m)

% R

efl

ec

tan

ce

Montmorillonite heated in Air Montmorillonite heated in Air

T = 1130oC

T = 630oC

T = 880oC

Untreated

Impact ExperimentsImpact Experiments Same claysSame clays

Montmorillonite (Ca, Al clay)Montmorillonite (Ca, Al clay) Nontronite (FeNontronite (Fe3+3+ clay) clay)

Impact with light gas gunImpact with light gas gun Velocity 2 - 3.3 km/sVelocity 2 - 3.3 km/s SUS projectileSUS projectile

AnalysisAnalysis XRDXRD Reflectance spectraReflectance spectra Autodyne softwareAutodyne software

Max pressure and temperatureMax pressure and temperature

Impacted nontroniteImpacted nontronite

No real changeNo real change All peaks still All peaks still

visiblevisible Interlayer peak Interlayer peak

intactintact Peak intensity Peak intensity

decreasedecrease


v = 2.47km/s

v = 3.27km/s

Offset by 400 units

0

10

20

30

40

50

60

70

80

90

100

1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6Wavelength (m)

% R

efl

ec

tan

ce

Impacted NontroniteImpacted Nontronite

Untreated

v = 2.5 km/s

v = 2.07 km/sv = 2.15 km/s

v = 3.27 km/s

Shock Wave Propagation ModelingShock Wave Propagation Modeling

v = 2.47km/s

10ms time step


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s


v = 2.47km/s

0

10

20

30

40

50

60

70

80

90

100

1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6Wavelength (m)

% R

efl

ec

tan

ce

Impacted MontmorilloniteImpacted Montmorillonite

Untreated

v = 2.5 km/s

Clays in Craters on MarsClays in Craters on Mars

Mangold, et al., 2007

10

11

12

13

14

15

16

17

18

1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6

Wavelength (m)

% R

efl

ec

tan

ce

Crater Ejecta

Crater Central Peak

Clays in Craters on MarsClays in Craters on Mars

0

10

20

30

40

50

60

70

80

90

100

1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6Wavelength (m)

% R

efl

ec

tan

ce

T = 630oC

T = 475oC

Magnetic PropertiesMagnetic Properties

T < 600T < 600ooC: C: paramagnetic Feparamagnetic Fe3+3+

T > 1000T > 1000ooC: C: Low saturation Low saturation

magnetizationmagnetization High remanent High remanent

magnetizationmagnetization High coercitive fieldHigh coercitive field Similar to hematiteSimilar to hematite

97

98

99

100

-10 -5 0 5 10

Counts A10293aSum Data A10293a

Rest DataSextet 1

Doublet 1

velocity (mm/s)

S1D1

A10293inte

nsi

ty (

%)

Applied Field (T)

Mag

netiz

atio

n (A

m2/k

g)

Magnetic PropertiesMagnetic Properties 800800ooC < T < C < T <

10001000ooC: Wasp-C: Wasp-waistedwaisted Two or more Two or more

components components presentpresent

Multidomain and Multidomain and paramagnetic paramagnetic particlesparticles

Maghemite?Maghemite?

97

98

99

100

-10 -5 0 5 10

Counts A10289c_#6Sum Data

Rest DataSextet 1

Doublet 1Sextet 3

inte

nsi

ty (

%)

velocity (mm/s)

A10289c, #6

S1

D1hem.

Applied Field (T)

Mag

netiz

atio

n (A

m2/k

g)

95

96

97

98

99

100

-10 -5 0 5 10

Counts A10291cSum Data A10291c

Rest DataSextet 1

Doublet 1

velocity (mm/s)

S1

D1

A10291

inte

nsi

ty (

%)

Mag

netiz

atio

n (A

m2/k

g)

Applied Field (T)

5.1 A

ConclusionsConclusions No distinctive effect of CONo distinctive effect of CO22 on clay on clay

transformationstransformations Heating: intense effect on claysHeating: intense effect on clays

Loss of water at relatively low temperaturesLoss of water at relatively low temperatures Melting and recrystallization at high temperaturesMelting and recrystallization at high temperatures Disappearance of bands in FTIRDisappearance of bands in FTIR

Impact affects smectitesImpact affects smectites Decrease in band depth (impact glass?)Decrease in band depth (impact glass?)

Magnetic propertiesMagnetic properties Possible new phase at intermediate temperaturesPossible new phase at intermediate temperatures Non-stiochiometric phaseNon-stiochiometric phase

Implications for MarsImplications for Mars Clays detected in small crater ejecta were Clays detected in small crater ejecta were

pre-existingpre-existing Different spectral features from untreated samplesDifferent spectral features from untreated samples Large impacts may generate enough heat to induce Large impacts may generate enough heat to induce

transformationstransformations Contact with lava flows should strongly affect claysContact with lava flows should strongly affect clays

Heated nontronite may explain origin and Heated nontronite may explain origin and magnetic properties of red dustmagnetic properties of red dust Hematite (superparamagnetic phase)Hematite (superparamagnetic phase) MaghemiteMaghemite

Documents

Effects of Impact and Heating on the Properties of Clays on Mars Patricia Gavin V. Chevrier, K. Ninagawa, S. Hasegawa