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Ammonium-bearing micas in very low-grade metapelites: micro- and nano-texture and composition

Published online by Cambridge University Press:  14 June 2018

Blanca Bauluz*
Affiliation:
IUCA-Facultad de Ciencias, Universidad de Zaragoza, Spain
Fernando Nieto
Affiliation:
Departamento de Mineralogía y Petrología and IACT, Universidad de Granada-CSIC, Spain
*

Abstract

The present study examines the micro- and nano-texture and composition of ammonium-bearing and potassium micas in very-low grade metamorphic black Silurian shales from the SE Iberian Range (NE Spain). Two organic-rich shales were studied by X-ray diffraction (XRD), infrared spectroscopy (IR), transmission electron microscopy (TEM), analytical electron microscopy (AEM) and electron energy loss spectroscopy (EELS). The XRD showed the presence of two populations of micas: pure K micas with d001 = 9.98 Å and ammonium-bearing micas with larger d001 values (10.08 Å and 10.05 Å). The latter values indicate NH4 contents between 13 and 29% in the interlayer, which was confirmed by IR. Interstratifications of smectite and mica layers in the mica packets were not detected by XRD and TEM. Mica packets with sizes ranging from 100 to 250 Å show disordered polytypes and (001) lattice fringes that reflect the presence of K- and NH4-bearing layers (9.9–10.2 Å).

The combination of AEM and EELS analyses on powdered and lamellar samples indicates that micas have typical dioctahedral compositions with highly variable K contents. This variation in K is consistent with the presence of K and NH4 in the interlayers, even though the NH4 and K are not distributed homogeneously; rather they are segregated in nm-sized domains in the mica interlayer.

Type
Article
Copyright
Copyright © Mineralogical Society of Great Britain and Ireland 2018 

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Footnotes

Guest Associate Editor: Sebastien Potel

This paper was presented during session GG01-01: ‘Clays in faults and fractures’ during the 2017 International Clay Conference

References

REFERENCES

Bauluz, B. & Subías, I. (2010) Coexistence of pyrophyllite, I-S, R1 and NH4+-rich illite in Silurian black shales (Sierra de Albarracín, NE Spain): metamorphic vs. hydrothermal origin. Clay Minerals, 45, 383392.Google Scholar
Bauluz, B., Peacor, D.R. & González-López, J.M. (2000) Transmission electron microscopy study of illitization in pelites from the Iberian Range, Spain: Layer-by-layer replacement? Clays and Clay Minerals, 48, 374384.Google Scholar
Bobos, I. (2012) Characterization of smectite to NH4-illite conversion series in the fossil hydrothermal system of Harghita Bai, east Carpathians, Romania. American Mineralogist, 97, 962982.Google Scholar
Cliff, G. & Lorimer, G.W. (1975) The quantitative analysis of thin specimens. Journal of Microscopy, 103, 203207.Google Scholar
Dalla-Torre, M., Livi, K., Veblen, D.R. & Frey, M. (1996) White K-mica evolution from phengite to muscovite in shales and shale matrix melange, Diablo Range, California. Contributions to Mineralogy and Petrology, 123, 390405.Google Scholar
Daniels, E.J. & Altaner, S.P. (1990) Clay mineral authigenesis in coal and shale from the Anthracite region, Pennsylvania. American Mineralogist, 75, 825-839.Google Scholar
Dong, H., Peacor, D.R. & Freed, R.L. (1997) Phase relations among smectite, R1 illite-smectite, and illite. American Mineralogist, 82, 379391.Google Scholar
Drits, V.A., Lindgreen, H. & Salyn, A.L. (1997) Determination of the content and distribution of fixed ammonium in illite-smectite by X-ray diffraction: Application to North Sea illite-smectite. American Mineralogist, 82, 7987.Google Scholar
Duit, W., Jansen, J.B.H., van Bremen, A. & Bos, A. (1986) Ammonium micas in metamorphic rocks as exemplified by Dome de l'Agout (France). American Journal of Science, 286, 702732.Google Scholar
Guidotti, C.V. & Sassi, F.P. (1998) Miscellaneous isomorphous substitutions in Na-K white mica; a review, with special emphasis to metamorphic micas. Rendiconti Lincei Scienze Fisiche e Naturali, 9, 5778.Google Scholar
Guidotti, C.V., Mazzoli, C., Sassi, F.P. & Blencoe, J.G. (1992) Compositional controls on the cell dimensions of 2M 1 muscovite and paragonite. European Journal of Mineralogy, 4, 283297.Google Scholar
Giorgetti, G., Memmi, I. & Nieto, F. (1997) Microstructures of intergrown phyllosilicate grains from Verrucano metasediments (Northern Apennines, Italy). Contributions to Mineralogy and Petrology, 128, 127138.Google Scholar
Guthrie, G.D. & Veblen, D.R. (1989) High-resolution transmission electron microscopy of mixed-layer illite/smectite: Computer simulation. Clays and Clay Minerals, 37, 111.Google Scholar
Guthrie, G.D. & Veblen, D.R. (1990a) High-resolution transmission electron microscopy applied to clay minerals. Pp. 7593 in: Spectroscopic Characterization of Minerals and their Surfaces (Coyne, L.M., McKeever, S.W.S. & Blake, D.F., editors). Symposia Series 415, American Chemical Society, Washington, D.C.Google Scholar
Guthrie, G.D. & Veblen, D.R. (1990b) High-resolution transmission electron microscopy of mixed-layer illite/smectite: Computer simulations. American Mineralogist, 75, 276288.Google Scholar
Higashi, S. (1982) Tobelite, a new ammonium dioctahedral mica. Mineralogical Journal, 11, 138146.Google Scholar
Higashi, S. (2000) Ammonium-bearing mica and mica/smectite of several pottery stone and pyrophyllite deposits in Japan: Their mineralogical properties and utilization. Applied Clay Science, 16, 171-184.Google Scholar
Juster, T.C., Brown, P.E. & Bailey, S.W. (1987) NH4-bearing illite in very low grade metamorphic rocks associated with coal, north-eastern Pennsylvania. American Mineralogist, 72, 555565.Google Scholar
Kim, J.W., Peacor, D.R., Tessier, D. & Elsass, F. (1995) A technique for maintaining texture and permanent expansion of smectite interlayers for TEM observations. Clays and Clay Minerals, 43, 5157.Google Scholar
Kozac, J., Ocenas, D. & Derco, J. (1977) The discovery of ammonium hydromica in the Vihorlat Mountains, eastern Slovakia. Mineralia Slovaca, 9, 6, 479.Google Scholar
Li, G.J., Peacor, D.R., Merriman, R.J. & Roberts, B. (1994) The diagenetic to low-grade metamorphic evolution of matrix white micas in the system muscovite-paragonite in a mudrock from Central Wales, United Kingdom. Clays and Clay Minerals, 42, 369381.Google Scholar
Livi, K.J.T., Veblen, D.R., Ferry, J.M. & Frey, M. (1997) Evolution of 2:1 layered silicates in low-grade metamorphosed Liassic shales of Central Switzerland. Journal of Metamorphic Geology, 12, 323344.Google Scholar
Livi, K.J.T., Christidis, G.E., Arkai, P. & Veblen, D.R. (2008) White mica domain formation: A model for paragonite, margarite, and muscovite formation during prograde metamorphism. American Mineralogist, 93, 520527.Google Scholar
Merriman, R.J., Roberts, B., Peacor, D.R. & Hirons, S.R. (1995) Strain-related differences in the crystal growth of white mica and chlorite: a TEM and XRD study of the development of metapelitic microfabrics in the Southern Uplands thrust terrane, Scotland. Journal of Metamorphic Geology, 13, 559576.Google Scholar
Nieto, F. (2002) Ammonium illite from anchimetamorphic shales associated with anthracite in the Zemplinicum of the Western Carpathians. American Mineralogist, 87, 205216.Google Scholar
Nieto, F., Ortega-Huertas, M., Peacor, D. & Arostegui, J. (1996) Evolution of illite/smectite from early diagenesis through incipient metamorphism in sediments of the Basque-Cantabrian Basin. Clays and Clay Minerals, 44, 304323.Google Scholar
Šuchá, V., Kraus, I. & Madejová, J. (1994) Ammonium illite from anchimetamorphic shales associated with anthracite in the Zemplinicum of the Western Carpathians. Clay Minerals, 29, 369377.Google Scholar
Vazquez, M., Bauluz, B., Nieto, F. & Morata, D. (2016) Illitization sequence controlled by temperature in volcanic geothermal systems: The Tinguiririca geothermal field, Andean Cordillera, Central Chile. Applied Clay Science, 134, 221234.Google Scholar
Veblen, D.R., Guthrie, G.D. Jr., Livi, K.J.T. & Reynolds, R.C. Jr. (1990) High-resolution transmission electron microscopy and electron diffraction of mixed-layer illite/smectite: Experimental results. Clays and Clays Minerals, 38, 113.Google Scholar
Ward, C.R. & Christie, P.J. (1994) Clays and other minerals in coal seams of the Moura-Baralaba area, Bowen Basin, Australia. International Journal of Coal Geology, 25, 287309.Google Scholar
Williams, L.B., Ferrell, R.E., Chinn, E.W. & Sassen, R. (1989) Fixed ammonium in clays associated with crude oils. Applied Geochemistry, 4, 605616.Google Scholar
Williams, L.B., Wilcoxon, B.R., Ferrell, R.E. & Sassen, R. (1992) Diagenesis of ammonium during hydrocarbon maturation and migration. Applied Geochemistry, 7, 123134.Google Scholar
Wilson, P.N., Parry, W.T. & Nash, W.P. (1992) Characterization of hydrothermal tobelitic veins from black shale, Oquirrh Mountains, Utah. Clays and Clay Minerals, 40, 405420.Google Scholar
Yamamoto, T. (1967) Mineralogical studies of sericite associated with Roseki ores in the western part of Japan. Mineralogical Journal, 5, 7797.Google Scholar