Hostname: page-component-76fb5796d-skm99 Total loading time: 0 Render date: 2024-04-26T05:10:31.975Z Has data issue: false hasContentIssue false

X-ray absorption study at the Fe K-edge of garnets from the Ivrea-Verbano zone

Published online by Cambridge University Press:  05 July 2018

Simona Quartieri
Affiliation:
Istituto di Mineralogia e Petrologia, Università di Modena, via S. Eufemia 19, 1-41100 Modena, Italy (Fax: 0039-59-223605)
Gianni Antonioli
Affiliation:
Dipartimento di Fisica, Università di Parma, Viale delle Scienze, 1-43100 Parma, Italy
Pier Paolo Lottici
Affiliation:
Dipartimento di Fisica, Università di Parma, Viale delle Scienze, 1-43100 Parma, Italy
Gilberto Artioli
Affiliation:
Istituto di Mineralogia e Petrologia, Università di Modena, via S. Eufemia 19, 1-41100 Modena, Italy (Fax: 0039-59-223605)

Abstract

K-edge X-ray absorption spectra of Fe in garnet samples from the Ivrea-Verbano zone were collected using synchrotron radiation. From XANES analysis, the prevalent oxidation state of Fe has been determined as 2+ in all studied samples. Coordination numbers and Fe-O bond lengths derived from the EXAFS analysis are compatible with a dodecahedral environment of Fe atoms and seem to be nearly independent of the variable Fe/Ca ratio of the cations sharing the dodecahedral site in these garnets. This suggests that, since at least up to 0.5 Ca atoms p.f.u, no sensible deformation of the dodecahedron geometry is sensed by the Fe cations, iron might strongly compete with Ca atoms in controlling the entry of rare earth elements in the dodecahedral site of garnets falling within this compositional range. Comparison of the EXAFS results with the data from single crystal X-ray diffraction structure refinements indicates a first shell neighbour distance accuracy of ±0.02 Å, using theoretical EXAFS phases and amplitudes. The Debye-Waller factors derived from the EXAFS analysis indicate a higher degree of disorder on the four longer Fe-O bond distances, in comparsion with the other four shorter distances of the height-coordinated cation; this could be related to the nonrigid polyhedral behaviour of the dodecahedral site.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1993

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.)

References

Amthauer, G., Annersten, H. and Hafner, S. S. (1976) The Mössbauer spectrum of 57Fe in silicate garnets. Zeits. Kristallogr., 143, 1455.Google Scholar
Apted, M. J. and Boettcher, A. L. (1981) Partitioning of rare earth elements between garnet and andesite melt: an autoradiographic study of P-T-X effects. Geochim. Cosmochim. Acta, 45, 827–37.Google Scholar
Armbruster, Th., Bürgi, H. B., Kunz, M., Gnos, E., Brönnimann, St., and Lienert, Ch. (1990) Variation of displacement paramctcrs in structure refinements of low albitc. Am. Mineral., 75, 135–40.Google Scholar
Armbruster, Th., Geiger, C. A., and Lager, G. A. (1992) Singlecrystal X-ray structure study of synthetic pyropcalmandinc garnets at 100 and 293 K. Am. Mineral., 77, 512–21.Google Scholar
Artioli, G. and Geiger, C. A. (1991) Fe in pumpellyite-group minerals: a combined diffraction and spec-troscopy study. Plinius, 6, 823.Google Scholar
Basso, R., Della Guista, A., and Zcfiro, L. (1981) A crystal chemical study of a Ti-containing hydrogarnet. NeuesJahrb. Mineral., Mh., 230-6.Google Scholar
Brown, G. E., Calas, G., Waychunas, G. A., and Petiau, J. (1988) X-ray absorption spectroscopy and its applications in mineralogy and geochemistry. In Spectroscopic methods bt mineraloKv and geology. F. C. Hawthorne, Ed.), pp. 431-512. Min. Soc. Amer. Reviews in Mineralogy, vol. 18.Google Scholar
Bürgi, H. B. (1989) Intcrpretation of atomic displace-ment parameters: intramolccular translation oscilla-tion and rigid-body motion. Acta Crystallogr., B45, 383-90.Google Scholar
Calas, G., Levitz, P., Pctiau, J., Bondot, P., and Loupias, G. (1980) Etude de l'ordre local autour du fcr dans des verres silicates naturcls et synthetiqucs a I'aide de la spectrometric d'absorption X. Rel,. Phys. Appl., 15, 1161–7.Google Scholar
Calas, G., Basset, W. A., Petiau, J., Steinberg, M., Tchoubar, D., and Zarka, A. (1984) Mineralogical appli-cations of synchrotron radiation. Phys. Chem. Minerals, 11, 1736.Google Scholar
Chandrasekhar, K. and Biirgi, H. B. (1984) Dynamic processes in crystals examined through difference vibrational parameters AU: the low-spin-high-spin transition in Tris(dithiocarbamato)iron(III) complexes. Acta Crystallogr., B40, 387-97.Google Scholar
Cressey, G. (1981) Entropics and entalpies of alumino-silicate garnets. Contrib. Mineral. Petrol., 76, 413–9.Google Scholar
Geiger, C. A., Armbruster, Th., Hager, G. A., Jiang, K., Lottcrmoser, W., and Amthauer, G. (1992) A combined temperature dependent 57Mössbauer and single crystal X-ray diffraction study of synthetic almandinc: evidence for the Goldanskii-Karyagin effect. Phys. Chem. Minerals, 19, 121–6.Google Scholar
Gibbs, G. V., and Smith, J. V. (1965) Refinement of the crystal structural of synthetic pyrope. Am. Mineral., 50, 2023–39.Google Scholar
Harrison, W. J. (1981) Partition coefficients for REE between garnets and liquids: implications of non-Henry's Law behaviour for models of basalt original and evolution. Geochim. Cosmochim. Acta, 45, 1529–44.Google Scholar
Harrison, W. J. and Wood, B. J. (1980) An experimental invcstigation of the partitioning of REE between garnet and liquid with reference to the role of defect equilibria. Contrib. Mineral. Petrol., 72, 145–55.Google Scholar
Haselton, H. T. and Westrum, E. F., Jr. (1980) low-temperature heat capacities of synthetic pyrope, grossular and pyrope60grossular40. Geochim. Cosmochim. Acta, 44, 701–9.Google Scholar
Kleber, W., Jost, K. H., and Ziemer, B. (1969) Zur Koordination des Magnesium im Pyrop und Unter-suchungcn fiber dessen thermischc Zersetzung. Krist. Techik., 4, 423–9.Google Scholar
Mazzucchelli, M., Rivalenti, G., Vannucci, R., Bottazzi, P., Ottolini, I., Hofmann, A. W., Sinigoi, S., and Dcmarchi, G. (1992) Trace clement distribution between clinopyroxcnc and garnet in gabbroic rocks of deep crust: an ion microprobe study. Geochim. Cosmochim. Acta. 56, 2371–85.Google Scholar
McKale, G., Veal, B. W., Paulikas, A. P., Chan, S. K., and Knapp, G. S. (1988) Improvcd ab initio calculations of amplitude and phase functions for extended X-ray absorption line structure spectroscopy. J. Am. Chem. Soc., 110, 3763–8.Google Scholar
McKay, G. A. (1989) Partitioning of rare earth elements betwcen major silicate minerals and basaltic melts. In Geochemistry and mineralogy of rare earth elements (F. C. llawthornc, Ed.), pp. 45-77. Min. Soc. Amcr. Reviews in Mineralogy, vol. 21.Google Scholar
Meagher, E. P. (1975) The crystal structures of pyrope and grossularitc at elevated temperaturcs. Am. Mineral., 60, 218–28.Google Scholar
Novak, G. A. and Gibbs, G. (1971) The crystal chemistry of the silicate garnets. Ibid., 60, 218-28.Google Scholar
Parenti, M. (1991) Petrologia di magmi ibridi in crosta profonda: equilibrio ed elementi in tracce in clino-pirosseno e granato. Degree thesis, University of Modena.Google Scholar
Quartieri, S., Dcriu, A., Artioli, G., Lottici, P. P., and Antonioli, G. (1993) 57Fe-Mossbauer investigation on garnets from the Ivrea-Verbano zone. Mineral. Mag. 57 (in press).Google Scholar
Rivalenti, G., Rossi, A., Siena, F., and Sinigoi, S. (1984) The layered series of the Ivrea-Verbano igneous complcx. Western Alps, Italy. Tschermaks, Mineral Petrogr. Mitt., 33, 7799.Google Scholar
Teo, B. K. (1986) EXAFS: basic principles and data analysis. In Inorganic Chemistrt; Concepts, vol. 9, Springcr-Verlag, New York, pp. 1349.Google Scholar
Tossel, J. A., Vaughan, D. J., and Johnson, K. H. (1973) The elctronic structure of ferric iron octa-hedrally coordinated to oxygen: a fundamental pa)lyhedral unit of iron bearing oxide and silicate minerals. Nature, 244, 425.Google Scholar
Tossel, J. A., Vaughan, D. J., and Johnson, K. H. (1974) The electronic structure of rutile, wustite and haematite from molecular orbital calculations. Ant. Mineral., 59, 319–34.Google Scholar
Voshage, H., Hofmann, A. W., Mazzucchelli, M., Rivalenti, G., Sinigoi, S., Raczek, I., and Demarchi, G. (1990) Isotopic evidence from the Ivrea zone for a hybrid lower cust formed by magmatic underplating. Nature, 347, 731–6.Google Scholar
Waychunas, G. A., Apted, M. J.,and Brown, G. E., Jr. (1983) X-ray K-edge absorption spectra of Fe min-erals and model compounds: near-edge structure. Phys. Chem. Minerals, 10, 19.Google Scholar
Waychunas, G. A., Apted, M. J.,and Brown, G. E., Jr. Brown, G. E., Jr., and Apted, M. J. (1986) X-ray K-edge absorption spectra of Fe minerals and model compounds: II. EXAFS. Ibid., 13, 31-47.Google Scholar
Willis, B. T. M., and Rooksby, It. P. (1952) Crystal structure and antiferromagnetism in haematitc. Proc. Physic. Soc., B65, 950-4.Google Scholar
Zemann, A. and Zemann, J. (1961) Veffeinerung dcr Kristallstruktur von synthetischem Pyrop, Mg3Al2(SiO4)3. Acta Crystallogr., 14, 835–7.Google Scholar
Zemann, A. and Zemann, J. (1961) Veffeinerung dcr Kristallstruktur von synthetischem Pyrop, Mg3Al2(SiO4)3. Acta Crystallogr., 14, 835–7.Google Scholar