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Microtexture and genesis of clay minerals from a turbiditic sequence in a Southern Pyrenees foreland basin (Jaca basin, Eocene)

Published online by Cambridge University Press:  09 July 2018

B. Bauluz*
Affiliation:
Departamento de Ciencias de la Tierra, Universidad de Zaragoza, Pedro Cerbuna 12, 50.009 Zaragoza, Spain
A. Yuste
Affiliation:
Departamento de Ciencias de la Tierra, Universidad de Zaragoza, Pedro Cerbuna 12, 50.009 Zaragoza, Spain
M. J. Mayayo
Affiliation:
Departamento de Ciencias de la Tierra, Universidad de Zaragoza, Pedro Cerbuna 12, 50.009 Zaragoza, Spain
A. B. Rodríguez-Navarro
Affiliation:
Departamento de Mineralogía y Petrología, Universidad de Granada, Avda. Fuentenueva s/n, 18002 Granada, Spain
J. M. González-López
Affiliation:
Departamento de Ciencias de la Tierra, Universidad de Zaragoza, Pedro Cerbuna 12, 50.009 Zaragoza, Spain
*

Abstract

A set of fine-grained samples from a turbiditic sequence in a Southern Pyrenees foreland basin (Jaca Basin, Eocene) were studied to determine the influence of tectonics (Pyrenean Orogeny) on phyllosilicate recrystallization and infer the grade and basin maturity. The samples from four different outcrops were examined by X-ray diffraction (XRD) and by scanning (SEM) and transmission electron microscopy (TEM) with special emphasis on clay-mineral characterization (e.g.illitic phases). The analysed samples have simple mineral assemblages and consist of detrital quartz, albite and calcite, scarce clay matrix (mainly illite with chlorite), and calcite and dolomite cement. The lack of other phyllosilicates such as mixed-layer illite-smectite (I-S), pyrophyllite, Na-micas, or kaolin minerals is quite remarkable. On the SEM scale, samples (with marl composition) have poorly sorted textures and high detrital contents. In many cases they show bedding and/or cleavage, and in some cases neither is observed. Most of the clay-sized illites show very similar crystallinity and b0 values (determined by XRD) and distributions of crystallite thickness (measured by TEM) in all the outcrops, which is typical of late-diagenesis illites forming under low-pressure conditions. These illites are parallel (or subparallel) to bedding or randomly orientated. They are also characterized by disordered polytypes and low K contents. In some TEM images, a second type of illite has been observed. This secondary illite occurs parallel to cleavage, with thicker crystals (25–35 layers), K contents in the interlayer, and a 2M1 polytype. The pole figure analysis shows that most of the clays have (00l) planes parallel (or subparallel) to bedding although there are abundant clays with random orientation. There is no trend in the clay orientation/disorientation from the south to the north of the basin. All the data indicate that the strain rate associated with the Pyrenean Orogeny has not been recorded in the turbidite sequence controlling the relative orientation of clays, although anchizonal clay crystallization is favoured as a minor process.

Type
Research Papers
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2012

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References

Allen, P.A. & Allen, J.R. (2005) Basin Analysis. Principles and Applications. Second edition, Blackwell Publishing, 549 pp.Google Scholar
Biscaye, P.E. (1965) Mineralogy and sedimentation of recent deep-sea clay in the Atlantic Ocean and adjacent seas and oceans. Geological Society of America Bulletin, 76, 803–832.Google Scholar
Choukroune, P. (1989) The ECORS Pyrenean deep seismic profile reflection data and the overall structure of an orogenic belt. Tectonics, 8, 23–39.Google Scholar
Essene, E.J. & Peacor, D.R. (1995) Clay mineral thermometry – A critical perspective. Clays and Clay Minerals, 43, 540–553.Google Scholar
Guidotti, C.V. & Sassi, F.P. (1986) Classification and correlation of metamorphic facies series by means of muscovite b0 data from low-grade metapelites. Neues Jahrbuch für Mineralogy (Abhandlungen), 153, 363–380.Google Scholar
Kisch, H.J. (1987) Correlation between indicators of very low-grade metamorphism. Pp. 227–300. in: Low-Temperature Metamorphism (Frey, M., editor). Blackie & Son, Glasgow.Google Scholar
Kisch, H.J. (1991) Illite crystallinity: Recommendations on sample preparation, X-ray diffraction settings, and interlaboratory samples. Journal of Metamorphic Geology, 9, 665–670.CrossRefGoogle Scholar
Kretz, R. (1983) Symbols for rock-forming minerals. American Mineralogist, 68, 277–279.Google Scholar
Lacroix, B., Buatier, M., Labaume, P., Travè, A., Dubois, M., Charpentier, D., Ventalon, S. & Convert-Gaubier, D. (2011) Microtectonic and geochemical characterization of thrusting in a foreland basin: Example of the South-Pyrenean orogenic wedge (Spain). Journal of Structural Geology, 33, 1359–1377.Google Scholar
Martín, J.D. (2004) Using XPowder: A software package for Powder X-Ray diffraction analysis. http://www.xpowder.comD.L.GR1001/04.ISBN84-609-1497-6. 105 pp. Spain.Google Scholar
McCaig, A.M., Tritlla, J. & Banks, D.A. (2000) Fluid mixing and recycling during Pyrenean thrusting: Evidence from fluid inclusion halogen ratios. Geochimica et Cosmochimica Acta, 64, 3395–3412.Google Scholar
Merriman, R.J. (2002) Contrasting clay mineral assemblages in British Lower Palaeozic slate belts: The influence of geotectonic setting. Clay Minerals, 37, 207–219.CrossRefGoogle Scholar
Merriman, R.J. (2005) Clay minerals and sedimentary basin history. European Journal of Mineralogy, 17, 7–20.Google Scholar
Merriman, R.J. & Kemp, S.J. (1996) Clay minerals and sedimentary basin maturity. Mineralogical Society Bulletin, no. 111, 7–8.Google Scholar
Merriman, R.J. & Frey, M. (1999) Patterns of very lowgrade metamorphism in metapelitic rocks. Pp. 61–107. in: Low-grade Metamorphism (Frey, M. & Robinson, D., editors). Blackwell Sciences, Oxford.Google Scholar
Merriman, R.J. & Peacor, D.R. (1999) Very low-grade metapelites: Mineralogy, microfabrics and measuring reaction progress. Pp. 10–60. in: Low-grade Metamorphism (Frey, M. & Robinson, D., editors). Blackwell Sciences, Oxford.Google Scholar
Millán Garrido, H., Oliva-Urcia, B. & Pocoví, J.A. (2006) La transversal de Gavarnie-Guara. Estructura y edad de los mantos de Gavarnie, Guara-Gèdre, y Guarga (Pirineo centro-occidental). Geogaceta, 40, 35–38.Google Scholar
Mullis, J., Stern, W.B. & de Capitani, C. (1993) Correlation of fluid inclusion temperatures with illite, smectite and chlorite crystallinity data and smear slide chemistry in sedimentary rocks from the external parts of the Central Alps (Switzerland). In: IGCP project 294, Very-low grade metamorphism Symposium, November, 1993, Santiago, Chile.Google Scholar
Munoz, J.A. (1992) Evolution of a continental collision belt: ECORS– Pyrenees crustal balanced section. Pp. 235–246. in: Thrust Tectonics (McClay, K.R., editor). Chapman and Hall, London.Google Scholar
Nieto, F., Ortega-Huertas, M., Peacor, D.R. & Aróstegui, J. (1996) Evolution of illite/smectite from early diagenesis through incipient metamorphism in sediments of the Basque-Cantabrian basin. Clays and Clay Minerals, 44, 304–323.Google Scholar
Nieto, F., Mellini, M. & Abad, I. (2010) The role of H3O+ in the crystal structure of illite. Clays and Clay Minerals, 58, 238–246.Google Scholar
Oliva-Urcia, B. & Pueyo, E.L. (2007) Rotational basement kinematics deduced from remagnetized cover rocks (Internal Sierras, southwestern Pyrenees). Tectonics, 26, TC4014.Google Scholar
Rodriguez-Navarro, A.B. (2006) XRD2DScan: A new software for polycrystalline materials characterization using two-dimensional X-ray diffraction. Journal of Applied Cristallography, 39, 905–909.Google Scholar
Roure, F., Choukroune, P., Berastegni, X., Muñoz, J.A., Villien, A., Matheron, P., Bareyt, M., Seguret, M., Camara, P. & Deramond, J. (1989) ECORS deep seismic data and balanced cross sections: Geometric constraints on the evolution of the Pyrenees. Tectonics, 8, 41–50.Google Scholar
Schultz, L.G. (1964) Quantitative interpretation of mineralogical composition from X-ray and chemical data for the Pierre shale. Professional Paper U.S. Geological Survey, 391-c, 31.Google Scholar
Teixell, A. & García-Sansegundo, J. (1995) Estructura del sector central de la Cuenca de Jaca (Pirineos meridionales). Revista de la Sociedad Geológica de España, 8, 215–228.Google Scholar
Travé, A., Labaume, P., Calvet, F. & Soler, A. (1997) Sediment dewatering and pore fluid migration along thrust faults in a foreland basin inferred from isotopic and elemental geochemical analyses (Eocene southern Pyrenees, Spain). Tectonophysics, 282, 375–398.Google Scholar
Warr, L.N. & Rice, A.H.N. (1994) Interlaboratory standardization and calibration of clay mineral crystallinity and crystallite size data. Journal of Metamorphic Geology, 12, 141–152.Google Scholar