Research Article Cathodoluminescence and Raman ...downloads.hindawi.com/journals/ijs/2016/1751730.pdf · Research Article Cathodoluminescence and Raman Spectromicroscopy of Forsterite

Research ArticleCathodoluminescence and RamanSpectromicroscopy of Forsterite in Tagish Lake MeteoriteImplications for Astromineralogy

Arnold Gucsik12 Ildikoacute Gyollai23 Hirotsugu Nishido4

Kiyotaka Ninagawa5 Matthew M R Izawa6 Cornelia Jaumlger7 Ulrich Ott8

Irakli Simonia9 Szaniszloacute Beacuterczi3 and Masahiro Kayama10

1 Department of Geology University of Johannesburg Auckland Park Johannesburg 2600 South Africa2 Konkoly Thege Miklos Astronomical Institute Research Centre for Astronomy and Earth Sciences Hungarian Academy of SciencesKonkoly Thege Miklos ut 15-17 Budapest 1121 Hungary

3 Cosmic Material Space Research Group Institute of Physics Department of Material Physics Faculty of ScienceEotvos Lorand University Pazmany Peter Setany 1a Budapest 1117 Hungary

4 Department of Biosphere-Geosphere System Science Okayama University of Science 1-1 Ridai-cho Okayama 700-0005 Japan5 Department of Applied Physics Okayama University of Science 1-1 Ridai-cho Kita-ku Okayama 700-0005 Japan6 University of Winnipeg 515 Portage Avenue Winnipeg MB Canada R3B 2E97 Laboratory Astrophysics Group The Max Planck Institute for Astronomy Institute of Solid State PhysicsThe Friedrich Schiller University Jena Helmholtzweg 3 07743 Jena Germany

8 Savaria University Center University of West Hungary Karolyi Gaspar ter 4 Szombathely 9700 Hungary9 School of Graduate Studies Ilia State University Kakutsa Cholokashvili Avenue 35 0162 Tbilisi Georgia10Department of Earth and Planetary Sciences Faculty of Science Kobe University 1-1 Rokkodai-cho Nada-ku Kobe 657-8501 Japan

Correspondence should be addressed to Arnold Gucsik argu1986hotmailcom

Received 31 October 2015 Accepted 28 January 2016

Academic Editor Jin Zhang

Copyright copy 2016 Arnold Gucsik et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The Tagish Lake meteorite is CICM2 chondrite which fell by a fireball event in January 2000 This study emphasizes thecathodoluminescence (CL) and Raman spectroscopical properties of the Tagish Lake meteorite in order to classify the meteoriticforsterite and its relation to the crystallization processes in a parent body The CL-zoning of Tagish Lake meteorite records thethermal history of chondrules and terrestrial weathering Only the unweathered olivine is forsterite which is CL-active Thevariation of luminescence in chondrules of Tagish Lake meteorite implies chemical inhomogeneity due to low-grade thermalmetamorphism The blue emission center in forsterite due to crystal lattice defect is proposed as being caused by rapid coolingduring the primary crystallization and relatively low-temperature thermal metamorphism on the parent body of Tagish Lakemeteorite This is in a good agreement with the micro-Raman spectroscopical data A combination of cathodoluminescence andmicro-Raman spectroscopies shows some potentials in study of the asteroidal processes of parent bodies in solar system

1 Introduction

The Tagish Lake meteorite fell on 18th January 2000 at 1643UTC [1] Tagish Lake fireball event endedwith airburst explo-sions near Carcross Yukon Territory Canada and debriscrossed the Yukon-British Columbia boundary with manyfragments finally landing onTakuArmof Tagish Lake British

Columbia Canada (59∘421015840 N 134∘121015840W)The original preat-mospheric mass of the Tagish Lake meteorite was estimatedat 200000 [1] 56000 [2] and 60000ndash90000 kg [3] TagishLake was initially classified as the first CI2 chondrite [4] buthas subsequently been regarded as an ungrouped C2 chon-drite with affinities to both CM and CI chondrites Out ofthe 10 kg recovered in total about 870 g was collected within

Hindawi Publishing CorporationInternational Journal of SpectroscopyVolume 2016 Article ID 1751730 8 pageshttpdxdoiorg10115520161751730

2 International Journal of Spectroscopy

about a week after the fall on 25th-26th January 2000 fromthe frozen lake surface [3] The Tagish Lake meteorite is abrecciated matrix-dominated material with multiple litholo-gies [5ndash9] Tagish Lake contains sparse olivine-dominatedchondrules generally of less than 1mm diameter alteredCAIs of up to 2mm diameter magnetite individual grains ofolivine Ca-Fe-Mn carbonates (calcite and siderite-magnesitewith rarer dolomite) and Fe-Ni sulfides including pyrrhotite(eg [1 5 6]) The chondrule mesostasis glass material ispartially replaced by phyllosilicates indicative of aqueousalteration [10] Most CAIs are completely altered to phyllosil-icates (mainly Mg-rich serpentine saponite) and carbonates(dolomite calcite) though some retain spinel-dominantprimary material [6] Tagish Lake matrix is mineralogicallysimilar to that of other aqueously altered carbonaceous chon-drites (CM CI and CR chondrites) and is composed of Mg-phyllosilicates fine-grained Fe-Ni sulfides magnetite andFe-Mg carbonates (eg [5 7 10]) Tagish Lakemeteorite is anunshocked (S1) type [1 6] likemost carbonaceous chondrites[1 11] Herd et al [10] identified carboxylic acids amino acidsand aliphatic and aromatic hydrocarbons in organic fractionsBrown et al [1] interpreted Tagish Lake meteorite low-tem-perature (perhaps approaching sim0∘C) aqueous alteration tohave taken place on awater-bearing parent asteroid similar tothe case of other aqueously altered carbonaceous chondriteswhile Hiroi et al [12] proposed the Tagish Lake meteorite asthe first sample of a D-type asteroid Mittlefehldt [13] con-cludes that the elemental composition of Tagish Lake isgenerally closer to CM chondrites than to CI but also foundthat some of the most volatile elements were higher than inCM The carbon content according to Grady et al [4] is581 wt which is higher than typical concentrations for CMorCI carbonaceous chondrites Carbon inTagish Lake occursin carbonate minerals [5] various organic compoundsand nanodiamonds (eg [4 10]) Brown et al [1] measuredoxygen isotopic compositions close to CI chondrites Gradyet al [4] observed higher concentrations of presolar nanodi-amonds in Tagish Lake than in any other meteorite Mittle-fehldt [13] concluded based primarily on the apparent higherconcentrations of presolar nanodiamonds (stardust grains)that the Tagish Lake parent body accreted at larger helio-centric distances than most other carbonaceous chondritesThe organic material in Tagish Lake meteorite was studiedby numerous groups including Pizzarello et al [14] andNakamura-Messenger et al [15] who proposed that theorganic globules in Tagish Lakematerial originated frompro-toplanetary disk

2 Samples and Experimental Procedure

Our Tagish Lake sample consisted of two thin sections whichare embedded in epoxy resin on a glassy slide Samples forthis study are from Spring 2000 (nonpristine) collection andoriginate from collection siteMG-02 [1 13]The sectionswereprepared by hand using isopropyl alcohol as the only solventand were set in Struers EpoFix epoxyThe same sections werestudied by Izawa et al [6] see their Figures 3 C-D 4 and8 One area has been selected from each of the slides eachcontaining forsterite-rich chondrules in fine-grained matrix

Chondrule olivine inTagish Lake is dominantly forsteriticin composition with Ca Cr and Mn as the most commonminor elements (eg [6 16]) Chondrule olivine in the thinsection studied here (the same as that used by Izawa et al [6])has an average Cr

2O3content of 030wt and MnO content

of 003wt [6] The grains are chemically homogeneous inSEM X-ray map [6] and are compositionally close to end-member forsterite (average chondrule olivine compositionFo989

for this section Izawa et al [6] their Table 2) CLcolor imaging was obtained using a luminoscope (ELM-3R)with a cooled charge-coupled device (CCD) camera whichwas operated with electron beams generated by excitationvoltage at 10 kV and beam current of 05mA This systemalso contains a cold cathode discharge tube and a vacuumchamberThediameter of electron beam spot at a fewmmsizeon the sample surface was controlled by a magnetTheNikonimaging system (DS-5Mc) was used to convert CL images todigital data

JSM-5410LV Scanning Electron Microscope (SEM) con-sisting of MiniCL detector with a multialkali photomulti-plier tube was used to obtain CL scanning images at highmagnification A grating monochromator of the SEM-CLfacility was used with the following operating conditions1200 groovesmm a focal length of 03m F of 42 limit ofresolution of 05 nm and slit width of 4mm at the inlet andoutlet CL spectral data were recorded by a photon countingmethod using a photomultiplier tube (Hamamatsu R2228)and converted to digital data

Further details of the CL equipment and analytical proce-dure can be seen in Kayama et al [17] The OriginPro 8J SR2software containing a peak fitting option (peak analyzer) wasused for the correction and deconvolution of each emissioncenter

Micro-Raman analyses were carried out using theLabRam Confocal Spectrometer (632 nm excitation) of theLaboratory Astrophysics Group of the Max Planck Insti-tute for Astronomy (Jena Germany) Single spectrum wasacquired with an integration time of 30 sec at 3 accumula-tions and spectral range of 100ndash4400 cmminus1 and 20x and 50xobjectives were used for the collection of Raman spectraHere we present Raman results selecting the most represen-tative Raman spectrum

3 Results

31 Optical Microscopy The studied area contains a stronglyaqueous-altered porphyritic chondrule (sim800120583m diameter)which has a fine-grained accretionary rim The formerlyglassy chondrule mesostasis has been replaced by phyllosil-icates which has been discernible in the optical images (Fig-ures 1(a) and 1(c))The individual olivine phenocrysts range is10ndash50 120583m in the longest dimension but a large 300 120583mamoe-boid olivine aggregate occurs in the chondrule The secondchondrule is less altered which is an intermediate betweengranular (TLa left side of chondrule) and barred texture (TLaright-side of chondrule) The mesostasis has been altered toa phyllosilicate-dominant material In both chondrules theolivine crystals show zoned structure whichmay correspondto structural inhomogeneity or lattice strain The area TLb

International Journal of Spectroscopy 3

(a)

sim1mm

(b)

(c) (d)

sim1mm

(e) (f)

Figure 1 Optical microscope ((a) reflected light and (c) cross-polarized modes) scanning electron microscope ((e) backscattered electronmicroscope and (b) cathodoluminescence) and cathodoluminescence color ((d) and (f) at high magnification of the selected grain) imagesof TLa area showing a forsteritic barred chondrule Scale width of the chondrule is around 1mm

is composed of mineral-fragment rich groundmass whichcontains a strongly altered forsterite chondrule (Figures 2(a)and 2(b))

32 Cathodoluminescence Spectral Features and Imaging Prop-erties In the area TLa both chondrules have dull red colorbut mesostasis of the barred part of the right-side chondrulehas grayish green color (Figures 1(d) and 1(f)) It is importantto note that these parts could also be trapped bits of diamondpolishing compounds The mesostasis has a number of redluminescent grains On the backscattered electron (BSE)image the granular-barred chondrule has a lighter alterationrim including metal (Fe-Ni) and phyllosilicates (Figure 1(e))The olivine grains in the chondrules show zoned higher lumi-nescence (MiniCL image) according to the distribution ofactivator elements (Figure 1(b)) The alteration rims for both

chondrules are composed of nonluminescentminerals (dom-inantly phyllosilicates) The dull luminescent grains havehigher luminescent and nonluminescent rims The changeof luminescence intensity in adjacent grains is due to inho-mogeneous distribution of CL activator elements Inside theolivine blue and light yellow inclusions occur

CL area b (TLb) is composed primarily of strongly alteredchondrule fragments (less than 300120583m) and isolated olivinefragments The matrix is composed of phyllosilicates car-bonates sulfides magnetite and organic material MoreoverIzawa et al [6] observed that the carbonate grains usuallyhave a ldquostreakrdquo in the scanning electronmicroscope-cathodo-luminescence (SEM-CL) images due to the long lifetime(phosphorescence rather than luminescence) (Figure 2(b))Mineral fragments in thematrix have red luminescence colorwhereas the nonaltered inner part of the chondrule has a blue

4 International Journal of Spectroscopy

(a)

sim200120583m

(b)

(c) (d)

sim200120583m

(e) (f)

Figure 2 Optical microscope ((a) reflected light and (c) cross-polarized modes) scanning electron microscope ((e) backscattered electronmicroscope and (b) cathodoluminescence) and cathodoluminescence color ((d) and (f) at high magnification of the selected grain) imagesof TLb area showing a highly altered forsteritic chondrule Scale width of the chondrule is around 1mm

luminescence color and red rim (Figures 2(d) and 2(f)) Inthe BSE image (Figure 2(e)) the inner part of the chondrule isdark andhas a ldquospongyrdquo textureThe alteration rimhas lighterBSE contrast and contains metallic grains The dark BSEindicates a predominance of low-Z elements like Mg Si andO consistent with forsterite [6] The MiniCL image showshomogenous strong luminescence intensity for the wholeinner part of the chondrule (Figure 2(b))

The CL spectra show broad luminescence centers at 400ndash460 600ndash650 and 700 nm TLb1 has less intensity in the600ndash700 nm region than TLb2 while in contrast to bothTLb spectra the TLa spectra have no luminescence centerat 400 nm Instead they have broad shoulders at 600ndash650700ndash720 and 750 nm (Figure 3(a)) After the peak fittingprocedure (see Samples and Experimental Procedure) a peakat 400 nm (TLb1-2 only) and shoulders at 600ndash650 and 700ndash800 nm can be identified (Figure 3(b)) On the energy scale

(Figure 3(c)) broad shoulders occur at 0ndash2 eV and a broadpeak appears at 25ndash35 eV

33 Raman Spectra Raman spectral features (Figure 4) of theselected forsterite grain (TLb) contain several very weak (vw)as well as weak (w) positions at 222 322 390 432 541 582605 668 and 735 cmminus1 and threemedium strong peaks (m) at637 916 and 963 cmminus1 The spectrum is dominated by a verystrong (vs) doublet peak at 823 and 855 cmminus1 with a shoulderpeak centered at 876 cmminus1 (Figure 4)

4 Discussion

41 Cathodoluminescence Microscopy and Spectroscopy ofForsterite from Tagish LakeMeteorite Cathodoluminescenceproperties of forsterite in meteorites were previously studied

International Journal of Spectroscopy 5In

tens

ity (c

ps)

250000

200000

150000

100000

50000

0

Wavelength (nm)300 400 500 600 700 800

TLa1TLa2

TLb1TLb2

(a)

Wavelength (nm)300 400 500 600 700 800

Inte

nsity

(cps

)

120000

100000

80000

60000

40000

20000

0

TLa1TLa2

TLb1TLb2

(b)

Inte

nsity

(au)

60000

40000

20000

0

Energy (eV)20 25 30 35 40

TLa1TLa2

TLb1TLb2

(c)

Figure 3 (a) Cathodoluminescence spectra of TLa and TLb areas in forsterite showing three major regions centered at 400ndash460 600ndash650and 700ndash800 nm (b) CL spectra of forsterite grains followed by a peak fitting procedure (c) CL intensity versus energy plot of the TagishLake forsterite The 174 eV peak corresponds to Cr3+ and the 194 eV peak is assigned to Mn2+

in the Kaba CV3 chondrite by Gucsik et al [19 20] Similarto those forsterite crystals in Tagish Lake show red-dull redluminescence The lack of luminescence in fractures as wellas decreased luminescence intensity in forsterite adjacent tofractures likely reflects increased concentration of Fe2+ insuch regions because of its quenching effect The two broadcenters at 630 nm in the red region and at 700ndash800 nm inthe IR region can be caused by Mn2+ ion as activator and bythe Cr3+ activator which may cause structural defects Thebroad luminescence centered at 400 nm in case of the TLbarea corresponds to a structural defect Recently Gucsik et al[21] described a tendency that an increasing supercooling rateduring the crystallization process of experimentally grownforsterite chondrules leads to a gradual cathodoluminescencecolor change ranging from red to greenish blue They foundthat the red CL color corresponds to growth rates of 20ndash100 micrometerssec whereas blue or greenish blue colors

correspond to rates of sim1000 micrometerssec Nishido et al[22] pointed out that CL-zoning records the thermal historyof chondrules During terrestrial weathering Fe2+ cationsare attached in the fractures resulting in quenching of lumi-nescence The unweathered meteoritic olivine (forsterite) onthe other hand is CL-active The variation of luminescenceintensity in chondrules of area A indicates chemical inho-mogeneity due to low degree of thermal metamorphism Atthe duller red luminescence centers of area TLa the olivinehas a fayalitic component whereas the light luminescentpatches are purely forsterite The fractures in chondrules arenonluminescent which is caused by either enrichment ofdivalent Fe due to parent body aqueous alteration terrestrialweathering or shock-driven diffusion of Fe2+ into the olivinelattice The blue luminescence center in area TLb is ascribedto intrinsic defects centers associated with either Al3+ sub-stitution for Si4+ in tetrahedral sites or lattice deformation

6 International Journal of Spectroscopy

200 300 400 500 600 700 800 900 1000 1100

800

1000

1200

1400

1600

1800

Inte

nsity

Tagish Lake meteoritic forsterite

Raman shift (cmminus1)

605 4

582 4(B1g) + 2(B2g)

222

T (S

iO4)

322

R (S

iO4)

390

4322(B

1g)

+2(B

2g)

5414 637

668

735

823 1 + 3855 1 + 3

8763

9163

9633

Figure 4 Raman spectrum of Tagish Lake forsterite showing adominant doublet peak at 823 and 855 cmminus1 which are assignedto symmetric and asymmetric stretching vibrational modes of theisolated SiO

4

tetrahedra [18]

due to substitution of Ca2+ and Ti4+ ions in octahedral sites[22 23]The broad emission at 650 nm (TLa TLb) is assignedto Mn2+ impurity centers in M2 positions of forsterite [2223] Finally the broad emission bands at 720 nm and higherwavenumber is attributed to Cr3+ substitutions in theM1 andM2 sites as well as interstitial positions of forsterite [22 23]

The energetic CL spectra were deconvolved using theMott-Seitzmodel [22]Thismodel obtains activation energiesof temperature-quenching luminescence from a proposednonradiative transition increasing with increasing sampletemperature [24 25] The activation energies for red emis-sions are centered at 18 and 174 eV for TLa-b where the174 eV peak corresponds to Cr3+ and the 194 eV peak corre-sponds to Mn2+ The activation energy in blue region (TLb)appears as broad band at 315 eV which corresponds to acrystallographic defect center probably microdefect centersdue to the rapid cooling history of forsterite [21] (Figure 3(b))

42 Raman Spectroscopy According to Chopelas [26] andKolesov andGeiger [18] Ramanproperties of forsterite shouldbe divided into two major spectral regions such as librationaland translational modes as well as stretching vibrations ofSiO4 In our study two peaks centered at 222 and 322 cmminus1 are

assigned to translation [T (SiO4)] and liberation [R (SiO

4)] of

the SiO4 A peak at 432 cmminus1 is a ]

2(B1g) + ]2(B2g) vibrational

mode and a vibration at 582 cmminus1 belongs to ]4(B1g)+]2(B2g)

In our Tagish Lake meteoritic forsterite there are two ]4

stretching modes centered at 541 and 605 cmminus1 Peaks at 823and 855 cmminus1 are related to ]

1+ ]3vibrational modes and

a shoulder peak at 876 and two weak bands are assigned to]3stretching vibration Four Raman spectral positions of the

meteoritic forsterite centered at 390 637 668 and 735 cmminus1are still poorly understood Compared to other meteoriticforsterite (see [19 27] and references therein) neither shock

metamorphism nor thermal effects were found in the Ramanproperties of our Tagish Lake meteoritic forsterite Howeverthe Raman characteristics of our forsterite sample containssome signatures of the rapid cooling (eg Raman peaks cen-tered at 390 637 668 and 735 cmminus1) [18] which are in agood agreement with the cathodoluminescence results of thisstudy

43 Forsterite Grains of Cometary Dust It is known that thedust of comets in the form of silicate and carbon grains aswell as the fine-grained icy particles that make the cometaryhalo causes the appearance of weak continuous spectrum ofcomets [28] Recently forsterite mineral has been detected inthe cometary dust [29] It means that forsterite might be thenoticeable component of the cometary silicate halos

Cometary halos might be influenced by the fluxes of solarcorpuscular radiation solar wind and plasma clouds Solarflaresmight play an important role in the processes of interac-tion of radiation with the cometary atmospheres The protonflares with outflows of protons with energy of more than12GeV are rare phenomena Proton flares with the energy of10MeV lt 119864 lt 100MeV are more frequent At the distanceof 1 AU from the Sun the proton fluxes of the solar windcan vary within 108ndash1010 cmminus2sminus1 [30] Relativistic particlesrequire not less than 8min for propagation at the distance of1 AU and the electrons of 50KeV or ions of 100MeV amuminus1require 18min and for ions 1MeV amuminus1 they require 29hours For large and small solar flares the characteristic valuesof released energies can be expressed as (3ndash5) sdot 1031 erg forelectrons (of 20KeV and higher) and (1ndash3) sdot 1031 erg for pro-tons (of 20MeV and higher) Among the important phenom-ena is also the ejection of fast particles with velocity exceeding1000 kmsminus1 Taking into account the velocities of the maincomponents of solar wind around 380 kmsminus1ndash800 kmsminus1 it isnecessary to note that the propagation of solar wind is limitedby the dimensions of the heliosphere of about 100 AU (astro-nomical unit) The release of a significant amount of energyduring the solar flares takes place for a short period of time inaverage for tens of minutes The fluxes of solar electrons andprotons colliding with cometary halos might cause an inten-sive cathodoluminescence of the grains of halosThe intensityof cathodoluminescence of halos grains can be especially highafter solar proton flares When halos grains are bombardedby electrons or protons its surface can start luminescingTheduration of cathodoluminescence of cometary grains mightvary from some minutes to several hours Too long exposureof cosmic luminophors to high-energy electrons (protons)can cause the luminophor destruction resulting in a full orpartial loss of their luminescence properties The practicaldetection of cathodoluminescence of cometary grains willdepend on (1) quantum yield (ℓ) of cathodoluminescence ofthe matter of the given grains and (2) albedo (119860) of the givenhalos Numerically for the case of cathodoluminescence ℓ ge40 and 119860 le 03 will be favorable for detection from groundbased telescopes

Forsterite quartz and some other minerals are lumi-nescing in red and blue spectral regions under the action ofthe fluxes of electrons The spectra of luminescence of these

International Journal of Spectroscopy 7

minerals are often characterised by wide structureless bandsin the red region with a peak near 600 nm

We have obtained CL spectra of Tagish Lake forsteritewith maximum near 440 and 650 nm CL spectra of thisforsterite are characterised in featureless nature with twomain bumps When the comet approaches the Sun its elec-tromagnetic and corpuscular radiation could excite intenseluminescence of the cometary halo including cathodolumi-nescence of the forsterite grains CL luminescence of suchforsterite particles may also be characterised in featurelessemissions in blue and red parts of the spectrum Suchluminescence emissions will be superimposed on the faintsolar continuum scattered by the cometary grains The activecometary phenomena including outbursts and flares are char-acterised in release of the inner substance of cometary nuclei(relict dust and relict ice) Among the relictsmight be pristineforsterite grains with the different sizes and shapesThe spec-tra of cometary outbursts have inmany cases featureless char-acter especially in blue range (maxima within 440ndash490 nm)Investigation of the cometary spectra obtained in time of out-bursts might be as the effective tool for revealing of pristinecometary substance including presolar forsterite Laboratorydata of CL of Tagish Lake forsterite (obtained by us) might besuitable comparative sources in investigation of the cometarydust (cometary astromineralogy) It will be especially usefulfor revealing of presolar minerals of cometary substance

5 Conclusions

(i) The CL zonation in Tagish Lake forsterite reflectsrapid cooling and crystallization of the chondrulemelts preserving both structural defects (responsiblefor the blue CL emission) and inhomogeneities ofactivator elements as well as possible remobilizationof activators by later fluid processes on the parentasteroid

(ii) We conclude that a combination of scanning electronmicroscope-cathodoluminescence and Raman spec-troscopy would be a powerful tool to understand notonly the asteroidal processes but also the astromin-eralogical aspects of crystallization in the early solarsystem

(iii) Moreover these techniques would be applied to themineralogical investigations for the future sample-return missions too

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

Matthew M R Izawa acknowledges funding from NSERCand theMineralogical Association of Canada Arnold Gucsikwas partly supported by the NRF Free-Standing Fellow-ship Program at the Department of Geology University ofJohannesburg South Africa Authors are grateful to Dr Phil

McCausland (University of Western Ontario Canada) forlending the Tagish Lake meteorite thin section for this study

References

[1] P G Brown A R Hildebrand M E Zolensky et al ldquoThe fallrecovery orbit and composition of the Tagish Lakemeteorite anew type of carbonaceous chondriterdquo Science vol 290 no 5490pp 320ndash325 2000

[2] P G Brown D O ReVelle E Tagliaferri and A R HildebrandldquoAn entry model for the Tagish Lake fireball using seismicsatellite and infrasound recordsrdquo Meteoritics and PlanetaryScience vol 37 no 5 pp 661ndash675 2002

[3] A R Hildebrand P J A McCausland P G Brown et al ldquoThefall and recovery of the Tagish Lake meteoriterdquoMeteoritics andPlanetary Science vol 41 no 3 pp 407ndash431 2006

[4] M M Grady A B Verchovsky I A Franchi I P Wrightand C T Pillinger ldquoLight element geochemistry of the TagishLake C12 chondrite comparison with CI1 and CM2meteoritesrdquoMeteoritics and Planetary Science vol 37 no 5 pp 713ndash7352002

[5] M E Zolensky K Nakamura M Gounelle et al ldquoMineralogyof Tagish Lake an ungrouped type 2 carbonaceous chondriterdquoMeteoritics and Planetary Science vol 37 no 5 pp 737ndash7612002

[6] M R M Izawa R L Flemming P J A McCausland GSoutham D E Moser and I R Barker ldquoMulti-techniqueinvestigation reveals new mineral chemical and textural het-erogeneity in the Tagish Lake C2 chondriterdquo Planetary andSpace Science vol 58 no 10 pp 1347ndash1364 2010

[7] M R M Izawa R L Flemming P L King R C Peterson andP J A McCausland ldquoMineralogical and spectroscopic inves-tigation of the Tagish Lake carbonaceous chondrite by X-raydiffraction and infrared reflectance spectroscopyrdquo Meteoriticsand Planetary Science vol 45 no 4 pp 675ndash698 2010

[8] A I Blinova C D K Herd and M J M Duke ldquoTestingvariations within the Tagish Lake meteorite-II whole-rockgeochemistry of pristine samplesrdquo Meteoritics and PlanetaryScience vol 49 no 6 pp 1100ndash1118 2014

[9] A I Blinova T J Zega C D K Herd and R M Stroud ldquoTest-ing variations within the Tagish Lake meteoritemdashI mineralogyand petrology of pristine samplesrdquo Meteoritics and PlanetaryScience vol 49 no 4 pp 473ndash502 2014

[10] C D K Herd A Blinova D N Simkus et al ldquoOrigin andevolution of prebiotic organicmatter as inferred from theTagishLake meteoriterdquo Science vol 332 no 6035 pp 1304ndash1307 2011

[11] E R D Scott K Keil and D Stoffler ldquoShock metamorphismof carbonaceous chondritesrdquoGeochimica et CosmochimicaActavol 56 no 12 pp 4281ndash4293 1992

[12] T Hiroi M E Zolensky and C M Pieters ldquoThe Tagish Lakemeteorite a possible sample from a D-type asteroidrdquo Sciencevol 293 no 5538 pp 2234ndash2236 2001

[13] D W Mittlefehldt ldquoGeochemistry of the ungrouped carbona-ceous chondrite Tagish Lake the anomalous CM chondriteBells and comparison with CI and CM chondritesrdquoMeteoriticsand Planetary Science vol 37 no 5 pp 703ndash712 2002

[14] S Pizzarello Y Huang L Becker et al ldquoThe organic content ofthe Tagish Lakemeteoriterdquo Science vol 293 no 5538 pp 2236ndash2239 2001

[15] KNakamura-Messenger SMessenger L P Keller S J Clemettand M E Zolensky ldquoOrganic globules in the Tagish Lake

8 International Journal of Spectroscopy

meteorite Remnants of the protosolar diskrdquo Science vol 314no 5804 pp 1439ndash1442 2006

[16] S D J Russell F J Longstaffe P L King and T E LarsonldquoThe oxygen-isotope composition of chondrules and isolatedforsterite and olivine grains from the Tagish Lake carbonaceouschondriterdquo Geochimica et Cosmochimica Acta vol 74 no 8 pp2484ndash2499 2010

[17] M Kayama S Nakano and H Nishido ldquoCharacteristics ofemission centers in alkali feldspar a new approach by usingcathodoluminescence spectral deconvolutionrdquo American Min-eralogist vol 95 no 11-12 pp 1783ndash1795 2010

[18] B A Kolesov and C A Geiger ldquoA Raman spectroscopic studyof Fe-Mg olivinesrdquo Physics and Chemistry of Minerals vol 31no 3 pp 142ndash154 2004

[19] A Gucsik T Endo E Nakazato et al ldquoCathodoluminescencecharacterization of the forsterite in Kaba meteorite an astro-mineralogical applicationrdquo in Proceedings of the 42nd Lunar andPlanetary Science Conference abs1157 The Woodlands TexUSA March 2011

[20] A Gucsik T Endo H Nishido et al ldquoCathodoluminescencemicroscopy and spectroscopy of forsterite fromKabameteoritean application to the study of hydrothermal alteration of parentbodyrdquo Meteoritics and Planetary Science vol 48 no 12 pp2577ndash2596 2013

[21] A Gucsik K Tsukamoto H Nishido et al ldquoCathodolumi-nescence microcharacterization of forsterite in the chondruleexperimentally grown under super coolingrdquo Journal of Lumi-nescence vol 132 no 4 pp 1041ndash1047 2012

[22] H Nishido T Endo K Ninagawa M Kayama and A Guc-sik ldquoThermal effects on cathodoluminescence in forsteriterdquoGeochronometria vol 40 no 4 pp 239ndash243 2013

[23] E J Benstock P R Buseck and I M Steele ldquoCathodolumines-cence ofmeteoritic and synthetic forsterite at 296 and 77KusingTEMrdquoAmericanMineralogist vol 82 no 3-4 pp 310ndash315 1997

[24] F Seitz ldquoAn interpretation of crystal luminescencerdquo Transac-tions of the Faraday Society vol 35 pp 74ndash85 1939

[25] N F Mott and R W Gurney Electronic Processes in IonicCrystals Clarendron Press Oxford UK 1948

[26] A Chopelas ldquoSingle crystal Raman spectra of forsterite fayaliteand monticelliterdquo American Mineralogist vol 76 no 7-8 pp1101ndash1109 1991

[27] F Rull M J Munoz-Espadas R Lunar and J Martınez-Frıas ldquoRaman spectroscopic study of four Spanish shockedordinary chondrites Canellas Olmedilla de Alarcon Reliegosand Olivenzardquo Philosophical Transactions of the Royal Society AMathematical Physical and Engineering Sciences vol 368 no1922 pp 3153ndash3166 2010

[28] I Simonia ldquoOn the possible luminescence nature of unidenti-fied cometary emissionsrdquo Astrophysics and Space Science vol312 no 1-2 pp 27ndash33 2007

[29] D S Lauretta L P Keller and S Messenger ldquoSupernova olivinefrom cometary dustrdquo Science vol 309 no 5735 pp 737ndash7412005

[30] R Noyes The Sun Our Star Harvard University Press Cam-bridge Mass USA 1983

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of