Hostname: page-component-77c89778f8-gvh9x Total loading time: 0 Render date: 2024-07-17T10:58:09.007Z Has data issue: false hasContentIssue false
  • English
  • Français

Preparation of TEM samples by focused ion beam (FIB) techniques: applications to the study of clays and phyllosilicates in meteorites

Published online by Cambridge University Press:  05 July 2018

M. R. Lee ,
P. A. Bland  and
G. Graham
M. R. Lee*
Affiliation:
Division of Earth Sciences, University of Glasgow, Lilybank Gardens, Glasgow G12 8QQ, UK
P. A. Bland
Affiliation:
Division of Earth Sciences, University of Glasgow, Lilybank Gardens, Glasgow G12 8QQ, UK
G. Graham
Affiliation:
Division of Earth Sciences, University of Glasgow, Lilybank Gardens, Glasgow G12 8QQ, UK
*
* E-mail: leemarti@earthsci.gla.ac.uk
Get access Rights & Permissions [Opens in a new window]

Abstract

Transmission electron microscope samples were prepared of ALH 78045 and ALH 88045, two clay-and phyllosilicate-bearing Antarctic meteorites, using argon ion milling and focused ion beam (FIB) techniques. ALH 78045 contains clay- and phyllosilicate-filled veins that have formed by terrestrial weathering of olivine, orthopyroxene and metal. Very narrow (∼10 nm) intragranular clay-filled veins could be observed in the TEM samples prepared by argon ion milling, whereas differential thinning and lack of precision in the location of the electron-transparent areas hindered the study of wider (5 — 15 μm) phyllosilicate-filled intergranular veins. Using the FIB instrument, electron-transparent slices were cut from specific parts of the wider veins and lifted out for TEM study. Results show that these veins are occluded by cronstedtite, a mixed-valence Fe-rich phyllosilicate. This discovery shows that silicates can be both dissolved and precipitated during terrestrial weathering within the Antarctic ice. ALH 88045 is one of a small number of known CM1 carbonaceous chondrites. This meteorite is largely composed of flattened ellipsoidal aggregates of serpentine-group phyllosilicates. To determine the mineralogy and texture of phyllosilicates within specific aggregates, TEM samples were prepared by trenching into the cut edge of a sample using the FIB instrument. Results show that Mg-rich aggregates are composed of lath-shaped serpentine crystals with a ∼0.73 nm basal spacing, which is typical of the products of low temperature aqueous alteration within asteroidal parent bodies. Results of this work demonstrate that the FIB has enormous potential in a number of areas of Earth and planetary science.

Keywords

focused ion beamcarbonaceous chondriteTEMcronstedtiteweathering.
Type
Research Article
Information
Mineralogical Magazine , Volume 67 , Issue 3 , June 2003 , pp. 581 - 592
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

†

Present address: Department of Earth Science and Engineering, Imperial College, Prince Consort Road, London SW7 2BP, UK

‡

Present address: Institute for Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, 7000 East Avenue, L-413, Livermore CA 94550, USA

References

Barber, D.J. (1970) Thin foils of non-metals made for electron microscopy by sputter-etching. Journal of Materials Science, 5, 1—8.CrossRefGoogle Scholar
Barber, D.J. (1981a) Demountable polished extra-thin sections and their use in transmission electron microscopy. Mineralogical Magazine, 44, 357—359.CrossRefGoogle Scholar
Barber, D.J. (1981b) Matrix phyllosilicates and associated minerals in C2M carbonaceous chondrites. Geochimica et Cosmochimica Acta, 45, 945—970.CrossRefGoogle Scholar
Barber, D.J. (1999) Development of ion-beam milling as a major tool for electron microscopy. Microscopy and Analysis, 36, 5—8.Google Scholar
Bland, P.A., Sexton, A.S., Jull, A.J.T., Bevan, A.W.R., Berry, F.J., Thornley, D.M., Astin, T.R., Britt, D.T. and Pillinger, C.T. (1998) Climate and rock weathering: A study of terrestrial age dated ordinary chondritic meteorites from hot desert regions. Geochimica et Cosmochimica Acta, 62, 3169—3184.CrossRefGoogle Scholar
Bland, P.A., Lee, M.R., Sexton, A.S., Franchi, I.A., Fallick, A.E., Miller, M.F., Cadogan, J.M., Berry, F.J. and Pillinger, C.T. (2000) Aqueous alteration without a pronounced oxygen isotope shift: Implications for asteroidal processing of chondritic materials. Meteoritics and Planetary Science, 35, 1387—1395.CrossRefGoogle Scholar
Giannuzzi, L.A., Prenitzer, B.I., DrownMacDonald, J.L., Brown, S.R., Irwin, R.B., Stevie, F.A. and Shofner, T.L. (1998) Advances in the FIB lift-out technique for TEM specimen preparation: HRTEM lattice imaging. Microstructural Science, 26, 249—253.Google Scholar
Giannuzzi, L.A., Prenitzer, B.I., Drown-MacDonald, J. L., Shofner, T.L., Brown, S.R., Irwin, R.B. and Stevie, F.A. (1999) Electron microscopy sample preparation for the biological and physical sciences using focused ion beams. Journal of Process Analytical Chemistry, 4, 162—167.Google Scholar
Gooding, J.L. (1986) Clay-mineraloid weathering products in Antarctic meteorites. Geochimica et Cosmochimica Acta, 50, 2215—2223.CrossRefGoogle Scholar
Graham, G.A., Charter, A.J., McPhail, D.S., Kearsley, A.T., Lee, M.R., Kettle, S. and Wright, I.P. (2002) In situ sectioning and analysis of cosmic dust using Focused Ion Beam microscopy. Meteoritics and Planetary Science, 37, 56.Google Scholar
Heaney, P.J., Vicenzi, E.P., Giannuzzi, L.A. and Livi, K.J.T. (2001) Focused ion beam milling: A method of site-specific sample extraction for microanalysis of Earth and planetary materials. American Mineralogist, 86, 1094—1099.CrossRefGoogle Scholar
Hendricks, S.B. (1939) Random structures of layer minerals as illustrated by cronstedtite. Possible iron content of kaolin. American Mineralogist, 24, 529—539.Google Scholar
Jull, A.J.T., Cheng, S., Gooding, J.L. and Velbel, M.A. (1988) Rapid growth of magnesium-carbonate weathering products in a stony meteorite from Antarctica. Science, 242, 417—419.CrossRefGoogle Scholar
Lee, M.R. and Bland, P.A. (2003) Mechanisms of weathering of meteorites recovered from hot and cold deserts and the formation of phyllosilicates. Geochimica et Cosmochimica Acta (in press).CrossRefGoogle Scholar
Muller, W.F., Kurat, G. and Kracher, A. (1979) A chemical and crystallographic study of cronstedtite in the matrix of the Cochabamba (CM2) carbonaceous chondrite. Tshermaks Mineralogische und Petrographische Mitteilungen, 26, 293—304.CrossRefGoogle Scholar
Newman, A.C.D. and Brown, G. (1987) The chemical constitution of clays. Pp. 1–128 in: Chemistry of Clays and Clay Minerals (Newman, A.C.D., editor). Monograph 6, Mineralogical Society, London.Google Scholar
Nishiizumi, K., Elmore, D. and Kubik, P.W. (1989) Update on terrestrial ages of Antarctic meteorites. Earth and Planetary Science Letters, 93, 299—313.CrossRefGoogle Scholar
Overwijk, M.H.F., van den Heuvel, F.C. and BulleLieuwma, C.W.T. (1993) Novel scheme for the preparation of transmission electron microscopy specimens with the focused ion beam. Journal of Vacuum Science Technology, 11, 202.Google Scholar
Roberts, S., McCaffrey, J., Giannuzzi, L., Stevie, F. and Zaluzec, N. (2001) Advanced techniques in TEM specimen preparation. Pp. 336–343 in: Progress in Transmission Electron Microscopy 1: Concepts and Techniques (Zhang, X.-F. and Zhang, Z. editors). Springer Verlag, Berlin.Google Scholar
Stroud, R.M., Alexander, C.M.O’D. and MacPherson, G.J. (2000) A precise new method of microsampling chondritic material for transmission electron microscope analysis: preliminary application to calcium- aluminium-rich inclusions and associated matrix material in the Vigarano CV3 meteorite. Meteoritics and Planetary Sciences Supplement, 35, A153–154.Google Scholar
Stroud, R.M., Nittler, L.R. and Alexander, C.M.O’D. (2002) Transmission electron microscopy of a presolar corundum. Meteoritics and Planetary Sciences Supplement,, 37, A137.Google Scholar
Velbel, M.A., Long, D.T. and Gooding, J.L. (1991) Terrestrial weathering of Antarctic stone meteorites: Formation of Mg-carbonates on ordinary chondrites. Geochimica et Cosmochimica Acta, 55, 67—76.CrossRefGoogle Scholar
Wlotzka, F. (1990) The Meteoritical Bulletin. Meteoritics, 25, 237—239.CrossRefGoogle Scholar
Zolensky, M., Barrett, R. and Browning, L. (1993) Mineralogy and composition of matrix and chon- drule rims in carbonaceous chondrites. Geochimica et Cosmochimica Acta, 57, 3123—3148.CrossRefGoogle Scholar
Zolensky, M.E., Mittlefehldt, D.W., Lipschutz, M.E., Wang, M-S., Clayton, R.N., Mayeda, T.K., Grady, M.M., Pillinger, C.T. and Barber, D.J. (1997) CM chondrites exhibit the complete petrologic range from type 2 to 1. Geochimica et Cosmochimica Acta, 61, 5099–5115.CrossRefGoogle Scholar