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Laser Raman identification of silica phases comprising microtextural components of sinters

Published online by Cambridge University Press:  05 July 2018

K. A. Rodgers
Affiliation:
Australian Museum, College Street, Sydney, NSW, Australia
W. A. Hampton*
Affiliation:
Department of Geology, University of Auckland, Private Bag 92019, Auckland, New Zealand
*

Abstract

Laser Raman spectroscopy is particularly well suited for routine characterization of the crystalline and the better ordered paracrystalline silica phases occurring in silica sinters: opal-C, quartz and moganite. The non-crystalline and poorly ordered paracrystalline silica phases (opal-CT and opal-A) are identified with difficulty, partly as a result of the high level of fluorescence exhibited by the younger sinters that are dominated by these phases, and partly as a result of the ill-defined nature of the broad phonon scattering bands produced by them. Nonetheless, given the limited number of phases present and the high level of phonon scattering from the better ordered phases, judicious use of a Raman microprobe enables the character of most siliceous microtextural sinter components to be determined readily. Microprobe examination of a series of New Zealand sinters, ranging from Late Quaternary to Pliocene in age shows that a silica phase inhomogeneity that exists in some outcrops reflects an underlying phase heterogeneity obtaining in the microstructure of the sinter; it is a consequence of the phase transformation process. In the older sinters, quartz, moganite and opaline cristobalite may be present in a single fabric element but in quite different proportions to their abundance in adjacent elements. Identification of opaline lepispheres partially pseudomorphed by quartz+moganite and the association of quartz+moganite in microcrystals exhibiting common quartz forms, cautions against the use of morphology as a means of identifying silica phases at the microstructural level.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2003

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References

Allen, K., Roberts, S. and Murray, J.W. (1999) Marginal marine agglutinated foraminifera; affinities for mineral phases. Journal of Micropalaeontology, 18, 183191.CrossRefGoogle Scholar
Bates, J.B. (1972) Raman spectra of a and p cristobalite. Journal of Chemical Physics, 57, 40424047.CrossRefGoogle Scholar
Campbell, K.A., Sannazzaro, K., Rodgers, K.A., Herdianita, N.R. and Browne, P.R.L. (2001) Sedimentary facies and mineralogy of the Late Pleistocene Umukuri silica sinter, Taupo Volcanic Zone, New Zealand. Journal of Sedimentary Research, 71, 727746.CrossRefGoogle Scholar
Farmer, J.D. (2000) Hydrothermal systems: doorways to early biosphere evolution. GSA Today, 10, 19.Google Scholar
Fournier, R.O. and Rowe, J.J. (1966) Estimation of underground temperatures from the silica content of water from hot springs and wet-steam wells. American Journal of Science, 264, 685697.CrossRefGoogle Scholar
Götze, J., Nasdala, L., Kleeberg, R. and Wenzel, M. (1998) Occurrence and distribution of “moganite” in agate/chalcedony: a combined micro-Raman, Rietveld and cathodoluminescence study. Contributions to Mineralogy and Petrology, 133, 96105.CrossRefGoogle Scholar
Heaney, P.J. and Post, J.E. (1992) The widespread distribution of a novel silica polymorph in microcrystalline quartz varieties. Science, 255, 441443.CrossRefGoogle ScholarPubMed
Herdianita, N.R., Browne, P.R.L., Rodgers, K.A. and Campbell, K.A. (2000a) Mineralogical and morphological changes accompanying aging of siliceous sinter and silica residue. Mineralium Deposita, 35, 4862CrossRefGoogle Scholar
Herdianita, N.R., Rodgers, K.A. and Browne, P.R.L. (2000b) Routine procedures to characterise the mineralogy of modern and ancient silica sinter deposits. Geothermics, 29, 6581.CrossRefGoogle Scholar
Keith, T.E.C., White, D.E. and Beeson, M.H. (1978) Hydrothermal alteration and self-sealing in Y-7 and Y-8 drill holes in the northern part of Upper Geyser Basin, YellowstoneNational Park, Wyoming. United States Geological Survey Professional Paper, 1054-A, 26 pp.Google Scholar
Kingma, K.J. and Hemley, R.J. (1994) Raman spectroscopic study of microcrystalline silica. American Mineralogist, 79, 269273.Google Scholar
Landmesser, M. (1995) Mobilitat durch Metastabilitat: SiO2 Transport und Akkumulation beiniedrigen Temperaturen. Chemie der Erde, 55, 149176.Google Scholar
Rodgers, K.A. (2000) Research on silica sinters. Mineralogical Society Bulletin 126(April), 1617.Google Scholar
Rodgers, K.A. (2001) Silica phases of New Zealand sinters. Geodiversity Symposium, Australian Museum, 4 December 2001. Journal and Proceedings of the Royal Society of New South Wales, 134, 112113.Google Scholar
Rodgers, K.A. and Cressey, G. (2001) The occurrence, detection and significance of moganite (SiO2)among some silica sinters. Mineralogical Magazine, 65, 157167.CrossRefGoogle Scholar
Skinner, D.N.B. (1976) Sheet N40 and parts of Sheets N35, N36 and N39 Northern Coromandel (1st edition). Geological Map of New Zealand 1:63,360. Map (1 sheet) and notes (28 p.) New Zealand Department of Scientific and Industrial Research, Wellington, New Zealand.Google Scholar
Smith, D.K. (1997) Evaluation of the detectability and quantification of respirable crystalline silica by X-ray powder diffraction. Powder Diffraction, 12, 200227.CrossRefGoogle Scholar
Smith, D.K. (1998) Opal, cristobalite, and tridymite: noncrystallinity versus crystallinity, nomenclature of the silica minerals and bibliography. Powder Diffraction, 13, 219.CrossRefGoogle Scholar
Splett, A., Splett, Ch. and Pilz, W. (1997) Dynamics of the Raman background decay. Journal of Raman Spectroscopy, 28, 481485.3.0.CO;2-L>CrossRefGoogle Scholar
Walter, M.R., Des Marais, D., Farmer, J.D. and Hinman, N.W. (1996) Lithofacies and biofacies of MidPaleozoic thermal spring deposits in the Drummond Basin, Queensland, Australia. Palios, 11, 497518.CrossRefGoogle ScholarPubMed
White, D.E., Hutchinson, R.A. and Keith, T.E.C. (1988) The geology and remarkable thermal activity of Norris Geyser Basin, Yellowstone National Park, Wyoming. US Geological Survey Professional Paper, 1456, 184.Google Scholar