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Contrasting alteration processes in hydrothermally altered dolerites from the Betic Cordillera, Spain

Published online by Cambridge University Press:  09 July 2018

J. Jiménez-Millán*
Affiliation:
Departamento de Geología, Universidad de Jaén, 23071 Jaén, Spain
I. Abad
Affiliation:
Departamento de Geología, Universidad de Jaén, 23071 Jaén, Spain
F. Nieto
Affiliation:
Departamento de Mineralogía y Petrología and IACT, Universidad de Granada-CSIC, 18002 Granada, Spain
*

Abstract

Dolerites from the Sierra de San Pedro (Betic Cordillera, southern Spain) develop three main types of microsystems during hydrothermal alteration: (1) centimetre-sized veins cross-cutting the dolerites; (2) microfractures in feldspar and diopside grains; and (3) alterations involving primary-igneous mafic phyllosilicate grains. The vein and microfracture sites developed alteration assemblages of randomly oriented smectites (saponite and beidellite) and halloysite. At these sites, the alteration mechanism was governed by complete dissolution of the parent material with subsequent crystallization of the products, with no parent-mineral crystallographic control. Pseudomorphed mafic phyllosilicate sites are characterized by oriented complex mineral assemblages made of chlorite, chlorite/smectite mixed layers, corrensite, saponite and relicts of biotite. These assemblages formed during the initial high-temperature stage of the hydrothermal process. In these microsites, the alteration sequence was controlled by the parent-mineral structure and chemistry, with products determined by structural relations with the parent phyllosilicate. Alteration of one phyllosilicate to the next most stable proceeds via interstratification of the parent and product phyllosilicates.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

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References

Abad, I., Jiménez-Millán, J., Molina, J.M., Nieto, F. & Vera, J.A. (2003) Anomalous reverse zoning of saponite and corrensite caused by contact metamorphism and hydrothermal alteration of marly rocks associated with subvolcanic bodies. Clays and Clay Minerals, 51, 543554.Google Scholar
Ahn, J.H. & Peacor, D.R. (1987) Kaolinitization of biotite - TEM data and implications for an alteration mechanism. American Mineralogist, 72, 353356.Google Scholar
Alt, J.C. (1999) Very low-grade hydrothermal metamorphism of basic igneous rocks. Pp. 169201 in: Low-grade Metamorphism (Frey, M. & Robinson, M., editors). Blackwell Science, Oxford.Google Scholar
Alt, J. & Teagle, D. (2003) Hydrothermal alteration of upper oceanic crust formed at a fast-spreading ridge: mineral, chemical, and isotopic evidence from ODP Site 801. Chemical Geology, 201, 191211.CrossRefGoogle Scholar
Anand, R.R., Gilkes, R.J., Armitage, T.M. & Hillyer, J.W. (1985) Feldspar weathering in lateritic saprolite. Clays and Clay Minerals, 33, 3143.Google Scholar
Armstrong, J.T. (1989) CITZAF: Combined ZAF and Phi-rho (Z) Electron Beam Correction Programs. California Institute of Technology, Pasadena, CA.Google Scholar
Banfield, J.F. & Barker, W.W. (1994) Direct observation of reactant-product interfaces formed in natural weathering of exsolved, defective amphibole to smectite: Evidence for episodic, isovolumetric reactions involving structural inheritance. Geochimica et Cosmochimica Acta, 58, 14191429.Google Scholar
Banfield, J.F. & Eggleton, R.A. (1988) Transmission electron-microscope study of biotite weathering. Clays and Clay Minerals, 36, 4760.CrossRefGoogle Scholar
Banfield, J.F. & Murakami, K. (1998) Atomic-resolution transmission electron microscope evidence for the mechanism by which chlorite weathers to 1:1 semi-regular chlorite-vermiculite. American Mineralogist, 83, 348357.Google Scholar
Banfield, J.F., Jones, B.F. & Veblen, D.R. (1991) An AEM-TEM study of weathering and diagenesis, Albert Lake, Oregon: I. Weathering reactions in the volcanics. Geochimica et Cosmochimica Acta, 55, 27812793.CrossRefGoogle Scholar
Barrenechea, J.F., Rodas, M., Frey, M., Alonso-Azcarate, J. & Mas, J.R. (2000) Chlorite, corrensite, and chlorite-mica in late Jurassic fluvio-lacustrine sediments of the Cameros basin of northeastern Spain. Clays and Clay Minerals, 48, 256265.CrossRefGoogle Scholar
Clayton, T. & Pearce, R.B. (2000) Alteration mineralogy of Cretaceous basalt from ODP Site 1001, Leg 165 (Caribbean Sea). Clay Minerals, 35, 719733.CrossRefGoogle Scholar
Cliff, G. & Lorimer, G.W. (1975) The quantitative analyses of thin specimens. Journal of Microscopy, 103, 203207.Google Scholar
Decarreau, A., Grauby, O. & Petit, S. (1992) The actual distribution of octahedral cations in 21 clay minerals: results from clay synthesis. Applied Clay Science, 7, 147167.Google Scholar
Dixon, J.B. & McKee, T.R. (1974) Internal and external morphology of tubular and spheroidal halloysite particles. Clays and Clay Minerals, 22, 127137.Google Scholar
Dong, H.L., Peacor, D.R. & Murphy, S.F. (1998) TEM study of progressive alteration of igneous biotite to kaolinite throughout a weathered soil profile. Geochimica et Cosmochimica Acta, 62, 18811887.Google Scholar
Eggleton, R.A. & Boland, J. (1982) Weathering of enstatite to talc through a sequence of transitional phases. Clays and Clay Minerals, 30, 1120.Google Scholar
Eggleton, R.A. (1986) The relations between crystal structure and silicate weathering rate. Pp. 2140 in: Rates of Chemical Weathering of Rocks and Minerals (Colman, S.M. & Dethier, D.P., editors). Academic Press, London.Google Scholar
Fiore, S., Huertas, F.J., Huertas, F. & Linares, J. (2001) Smectite formation in rhyolitic obsidian as inferred by microscopic (SEM-TEM-AEM) investigation. Clay Minerals, 36, 489500.Google Scholar
Grauby, O., Petit, S., Decarreau, A. & Baronnet, A. (1993) The beidellite-saponite series: an experimental approach. European Journal of Mineralogy, 5, 623635.Google Scholar
Hochella, M.F. & Banfield, J.F. (1995) Chemical weathering of silicates in nature: a microscopic perspective with theoretical considerations. Pp. 353401 in: Chemical Weathering Rates of Silicate Minerals (White, A.F. & Brantley, S.L., editors). Reviews in Mineralogy 31, Mineralogical Society of America, Washington, D.C. Google Scholar
Huertas, J., Fiore, S. & Linares, J. (2004) In situ transformation of amorphous gels into spherical aggregates of kaolinite: AHRTEM study. Clay Minerals, 39, 423431.CrossRefGoogle Scholar
Jiang, W.T. & Peacor, D.R. (1991) Transmission electron-microscopic study of the kaolinitization of muscovite. Clays and Clay Minerals, 39, 113.Google Scholar
Jiang, W.T. & Peacor, D.R. (1994) Formation of corrensite, chlorite and chlorite-mica stacks by replacement of detrital biotite in low-grade pelitic rocks. Journal of Metamorphic Geology, 12, 867884.Google Scholar
Kretz, R. (1983) Symbols for rock-forming minerals. American Mineralogist, 68, 277279.Google Scholar
Le Gleuher, M., Livi, K.J.T., Veblen, D., Noack, Y. & Amouric, M. (1990) Serpentinization of enstatite from Pernes, France: Reaction microstructures and the role of system openness. American Mineralogist, 75, 813824.Google Scholar
Li, G.J., Peacor, D.R. & Essene, E.J. (1998) The formation of sulfides during alteration of biotite to chlorite-corrensite. Clays and Clay Minerals, 46, 649657.Google Scholar
Mazer, J.J., Bates, J.K., Bradley, J.P., Bradley, C.R. & Stevenson, C.M. (1992) Alteration of tektite to form weathering products. Nature, 357, 573576.CrossRefGoogle Scholar
Molina, J.M. & Vera, J.A. (1999) Sedimentacion marina somera sobre edificios volcánicos submarinos (Jurásico medio-superior, Subbético Medio, Cordilleras Béticas). Pp. 91106 in: Libro Homenaje a JoséRamírez del Pozo. A.G.G.E.P., Madrid.Google Scholar
Molina, J.M. & Vera, J.A. (2000) Influencia del subvolcanismo en la sedimentacion pelágica del Jurásico medio (Sierra de San Pedro, provincia de Jaén, Subbético medio). Geogaceta, 27, 111114.Google Scholar
Nahon, D. (1991) Introduction to the Petrology of Soils and Chemical Weathering. Wiley, New York.Google Scholar
Pichler, T., Ridley, W.I. & Nelson, E. (1999) Low-temperature alteration of dredged volcanics from the Southern Chile Ridge - additional information about early stages of sea-floor weathering. Marine Geology, 159, 155177.Google Scholar
Portugal, M., Morata, D., Puga, E., Demant, A. & Aguirre, L. (1995) Evolucion geoquímica y temporal del magmatismo básico mesozoico en las Zonas Externas de las Cordilleras Béticas. Estudios Geológicos, 51, 109118.Google Scholar
Robertson, I.D. & Eggleton, R.A. (1991) Weathering of granitic muscovite to kaolinite and halloysite and of plagioclase derived kaolinite to halloysite. Clays and Clay Minerals, 39, 113126.Google Scholar
Sheets, J.M. & Tettenhorst, R.T. (1997) Crystallographic controls on the alteration of microcline perthites from the Spruce Pine District North Carolina. Clays and Clay Minerals, 45, 404417.Google Scholar
Singh, B. & Gilkes, R.J. (1992) An electron optical investigation of alteration of kaolinite to halloysite. Clays and Clay Minerals, 40, 212229.CrossRefGoogle Scholar
Veblen, D.R. (1991) Polysomatism and polysomatic series: a review and applications. American Mineralogist, 76, 801826.Google Scholar
Vera, J.A., Molina, J.M., Montero, P. & Bea, F. (1997) Jurassic guyots on the southern Iberian Continental margin: a model of isolated carbonate platforms in volcanic submarine edifices. Terra Nova, 9, 163166.CrossRefGoogle Scholar
Yamada, H., Yoshioka, K., Tamura, K., Fujii, K. & Nakazawa, H. (1999) Compositional gap in dioctahedral-trioctahedral smectite system: Beidellite-saponite pseudo-binary join. Clays and Clay Minerals, 47, 803810.Google Scholar