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A rectorite-pyrophyllite-chlorite-illite assemblage in pelitic rocks from Colombia

Published online by Cambridge University Press:  09 July 2018

B. Brattli
B. Brattli*
Affiliation:
Department of Geology and Mineral Resources Engineering, Norwegian University of Scienee and Technology, 7034 Trondheim, Norway
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Abstract

In samples of slate from the Fomeque Formation near Bogota, Colombia, pyrophyllite was found to occur together with mixed-layered illite-smectite, chlorite and illite. Other minerals were quartz, K-feldspar, dolomite and pyrite. X-ray diffraction patterns revealed that the mixed-layer represents an R1 ordered rectorite with 80–90% illite layers. The microfabric is developed as a closely spaced cleavage in the phyllosilicate-rich rocks, and grades into a fracture cleavage with coarsening of the grain size. No cleavage was observed in the interbedded siltstones. It is suggested that the microfrabrics developed in these rocks correspond to high diagenetic to anchizonal conditions. The illite crystallinity from the slate has been measured on glycolated samples and ranges from 0.47 to 0.55°Δ2θ with a mean of 0.52°Δ2θ Based on the stability of R1 ordered rectorite, the illite crystallinity and the microfabric development, it is proposed that the rocks have been subjected to a temperature of ∼200°C at low pressure. At this temperature, pyrophyllite can only be stabilized at the expense of kaolinite and quartz if aH2O ≪ 1.

Type
Research Article
Information
Clay Minerals , Volume 32 , Issue 3 , September 1997 , pp. 425 - 434
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1997

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References

Alonso, O.E. & Brime, C. (1970) Mineralogy, geochemistry, and origin of underclays of the Central Coal Basin, Asturias, Spain. Clays Clay Miner. 38, 265–276.Google Scholar
Brattli, B. & Broch, E. (1995) Stability problems in water tunnels caused by expandable minerals. Pressure measurements and mineralogical analyses. Eng. Geol. 39, 151–169.Google Scholar
Chatterjee, N.D. (19731 Low-temperature compatibility relation of the assemblage quartz-paragonite and the thermodynamic status of the phase rectorite. Contrib. Mineral. Petrol. 42, 259–271.Google Scholar
Chennaux, G., Dunoyer de Segonzac, G. & Petracco, F. (1970) Genèse de la pyrophyllite dans le Paléozoique du Sahara occidental. C. R. Acad. Sci. Paris, Sdrie D, 270, 2405–2408.Google Scholar
Dixon, J.E. & Weed, S.B. (19771 Minerals in Soil Environments. Soil Science Society of America, Madison, Wisconsin, USA.Google Scholar
Dunoyer de Segonzac, G. (1969) Les minéraux argileux darts la diagenèse - passage au métamorphisme. Mém. Serv. Carte géol. Alsace Lorraine, 29, 317 p.Google Scholar
Dunoyer de Segonzac, G. & Heddebout, C. (1971) Paléozoique anchi-métamorphique a illite, chlorite, pyrophyllite, allevardite et paragonite dans les Pyrénées Basques. Bull. Serv. Carte géol. Alsace Lorraine, 24, 277–290.Google Scholar
Eslinger, E. & Pevear, D. (1988) Clay minerals for petroleum geologists and engineers. SEPM Short Course, Notes no. 22. Soc. Econ. Paleont. Mineral.Google Scholar
Frey, M. (1987) Very low grade metamorphism of clastic sedimentary rocks. Pp. 9–58 in: Low-Temperature Metamorphism. (Frey, M., editor). Blackie & Son Ltd, Glasgow.Google Scholar
Frey, M. (1978) Progressive low-grade metamorphism of a black shale formation, Central Swiss Alps, with special reference to pyrophyllite and margarite bearing assemblage. J. Pet. 19, 95–135.Google Scholar
Henderson, G.V. (197(/) The origin of pyrophylliterectorite in shales of north central Utah. Clays Clay Miner. 18, 239–246.Google Scholar
Hoffmann, J. & Hower, J. (1979) Clay mineral assemblages as low grade metamorphic geothermometres; application to the thrust faulted Disturbed Belt of Montana, U.S.A. Pp. 55-80 in: Aspects of Diagenesis. (Scholle, P.A. & Schluger, P.R., editors). Soc. Econ. Paleont. Miner. Spec. Publ. 26.Google Scholar
Hower, J. (19811 X-ray diffraction identification of mixed layer clay minerals. Pp. 39–60 in: (Longstaffe, F.J., editor), Min. Ass. Canada Short Course in Clays and the Resource Geologists, Calgary, 7, 39–60.Google Scholar
Jennings, S. & Thompson, G.R. (1986) Diagenesis in Plio-Pleistocene sediments in the Colorado River delta, southern California. J. Sed. Pet. 56. 89-98.Google Scholar
Kisch, H.J. (1980) Illite crystallinity and coal rank associated with lowest-grade metamorphism of the Taveyanne greywacke in the Helvetic zone of the Swiss Alps. Eclogae Geologicae Helvetiae, 73, 753–777.Google Scholar
Kisch, H.J. (1983) Mineralogy and petrology of burial diagenesis (burial metamorphism) and incipient metamorphism in clastic rocks. Pp. 289-493, 513–541 in: Diagenesis in Sediments and Sedimentary Rocks 2 (Larsen, G. & Chilingar, G.V., editors). Elsevier, Amsterdam-Oxford-New York.Google Scholar
Kisch, H.J, (1990) Calibration of the anchizone: a critical comparison of illite ‘crystallinity’ scales used for definition. J. Met. Geol. 8, 31–46.Google Scholar
Kisch, H.J. (1991a) Illite crystallinity: recommendation on sample preparation, X-ray diffraction settings, and interlaboratory samples. J. Met. Geol. 9, 665–670.Google Scholar
Kisch, H.J. (1991b) Development of slaty cleavage degree of very low-grade metamorphism: a review. J. Met. Geol. 9, 735–750.Google Scholar
Kübler, B. (1964) Les argiles, indicateurs de métamorphisme. Rev. l'Inst. Fr. Pdtr. 19, 1093–1112.Google Scholar
Kübler, B. (1967) La cristallineté de l'illite et les zones tout à fait supdrieures du métamorphisme, Étages Tectoniques – Colloque de Neuchatel, A la Baconnibre, Neuchdtel, Suisse, 105 – 121.Google Scholar
Ktibler, B. (1984) Les indicateurs des transformations physiques et chimiques dans la diagenése, température et calorimdtrie. Pp. 489–596 in: Thdrmomdtrie et baromdtrie gdologiques (Lagache, M., editor), Soc, Franç. Minér. Crist., Paris.Google Scholar
McDowell, S.D. & Elders, W.A. (1980) Authigenic layer silicate minerals in borehole Elmore 1, Salton Sea geothermal field, California. Contrib. Min. Pet. 74, 293–310.CrossRefGoogle Scholar
Moore, D.M. & Reynolds Jr. R.C. (1989) X-ray Diffraction and the Identification and Analysis of Clay Minerals. Oxford-New York, Oxford University Press.Google Scholar
Steiner, A. (1968) Clay minerals in hydrothermally altered rocks at Wairakei, New Zealand. Clays Clay Miner. 16, 193–213.Google Scholar
Velde, B. (1985) Clay minerals: a Physico-chemical Explanation of their Occurrence. Elsevier, Amsterdam.Google Scholar
Winkler, H.G.F. (1967) Petrogenesis of Metamorphic Rocks. Second ed. Springer Verlag, New York, Berlin.Google Scholar
Winkler, H.G,F, (19791 Petrogenesis of Metamorphic Rocks. Fifth ed. Springer Verlag, New York, Berlin.Google Scholar