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Authigenic Ti-Bearing Crystals in a Precambrian Clay from Buenos Aires Province, Argentina

Published online by Cambridge University Press:  01 January 2024

Wanda Alló
Wanda Alló*
Affiliation:
Department of Geological Sciences, Indiana University, Bloomington, IN 47405, USA
*
*E-mail address of corresponding author: wallo@criba.edu.ar
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Abstract

The Precambrian Villa Mónica Formation clay was analyzed using petrographic and scanning electron microscopy, X-ray diffraction and chemical analysis, with the aim of characterizing the Ti-bearing phases present and determining their possible origin and/or source. Two Ti-bearing minerals were found to be present, rutile and anatase. The crystals are needles between 5 and 15 µm in size, with no evidence of abrasion or corrosion. They are commonly found in association with the (001) faces of illite flakes or in the pores between the flakes. Their disposition is similar in the three quarries studied. No zonation or differential settling due to differences in specific gravity was observed. In addition, chemical analyses indicated a positive correlation between TiO2 and K2O suggesting that both oxides behave similarly after the deposition of the sediment. The TiO2 content in the bulk fraction ranges from 0.8 to 1.98 wt.%, values that are similar to those exhibited in other clay deposits from different ages and geneses.

All observations are consistent with an in situ origin of these Ti-bearing phases during post-depositional processes that included recrystallization of existing minerals and crystallization of new phases. The original detrital minerals such as biotite, ilmenite as well as detrital illite, were the primary sources of the TiO2 and of the Fe oxides that coat the clay. Understanding the origin and the reaction mechanisms involved during the post-depositional alteration of the Villa Mónica Formation suggests that the Ti-bearing phases in different sediment types were formed by similar mechanisms involving redox processes at low to medium temperatures, even in Precambrian sediments where the presence of rutile could lead to an incorrect assumption of high temperatures involved.

Keywords

AnataseCompositional DataIllitePrecambrian ClayRutileSEMX-ray Diffraction
Type
Research Article
Information
Clays and Clay Minerals , Volume 52 , Issue 3 , June 2004 , pp. 304 - 310
Copyright
Copyright © 2004, The Clay Minerals Society

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References

Aitchison, J., (1986) The Statistical Analysis of Compositional Data London Chapman & Hall 10.1007/978-94-009-4109-0 416 pp.Google Scholar
Alló, W.A., (2001) Los yacimientos de arcillas illítica ferruginosas La Siempre Verde y La Placeres de Barker. La relación entre plasticidad, mineralogía, diagénesis y usos cerámicos Argentina Department of Geology, Universidad Nacional del Sur PhD thesis.Google Scholar
Alló, W.A. and Domínguez, E.A., (2002) Macrocristales diagenéticos de cuarzo en la facies pelítica de la Fm. Villa Mónica, Barker, Provincia de Buenos Aires XV Congreso Geol ó gico Argentino Argentina El Calafate.Google Scholar
Alló, W.A., Domínguez, E.A. and Cravero, F. (1996) Caracterización de la illita del yacimiento La Siempre Verde, Barker, Buenos Aires: politipos indicadores de un rango termal entre diagénesis profunda y metamorfismo leve. III Reuni ó n de Mineralog í a y Metalogenia, Argentina, pp. 27–35.Google Scholar
Berger, G. Velde, B. and Aigouy, T., (1999) Potassium sources and illitization in Texas Gulf Coast shale diagenesis Journal of Sedimentary Research 69 151–157 10.2110/jsr.69.151.Google Scholar
Deer, W.A. Howie, R.A. and Zussman, J., (1992) An Introduction to the Rock-forming Minerals 2nd Harlow, Essex, UK Longmans 696 pp.Google Scholar
Force, E.R. (1991) Geology of titanium-mineral deposits. Geological Society of America Special Paper, 259, 112 pp.Google Scholar
Grey, I.E. and Reid, A.F., (1975) The structure of pseudorutile and its role in the natural alteration of ilmenite American Mineralogist 60 898–906.Google Scholar
Iñiguez, A.M. del Valle, A. Poiré, D.G. Spalletti, L.A. Zalba, P.E., Chebli, G. and Spalletti, L., (1989) Cuenca Precámbrica/Paleozoica inferior de Tandilia, Provincia de Buenos Aires Cuencas Sedimentarias Argentinas Argentina San Miguel de Tucumán 245–263.Google Scholar
Konta, J. and Borovec, Z. (1966) Heavy minerals in raw kaolin from Zettlitz Bohemia. Interceram, 15, No. 2 and 3.Google Scholar
Loughnan, F.C., (1969) Chemical Weathering of the Silicate Minerals New York Elsevier 154 pp.Google Scholar
Morad, S. and Aldahan, A.A., (1982) Authigenesis of titanium minerals in two Proterozoic sedimentary rocks from Southern and Central Sweden Journal of Sedimentary Petrology 52 1295–1305.Google Scholar
Nagelschmidt, G. Donnelly, H.F. and Morcom, A.J., (1949) On the occurrence of anatase in sedimentary kaolin Mineralogical Magazine 28 492–495 10.1180/minmag.1949.028.204.05.Google Scholar
Poiré, D.C., (1987) Mineralogía y Sedimentología de la Formación Sierras Bayas en el núcleo septentrional de las Sierras homónicas, Olavarría, Prov. de Bs. As Argentina Museo de La Plata PhD thesis.Google Scholar
Sayin, M. and Jackson, M.L., (1975) Anatase and rutile determination in kaolin deposits Clays and Clay Minerals 23 437–443 10.1346/CCMN.1975.0230605.Google Scholar
Schroeder, P.A. and Shiflet, J., (2000) Ti-bearing phases in the Huber Formation, an East Georgia kaolin deposit Clays and Clay Minerals 48 151–158 10.1346/CCMN.2000.0480201.Google Scholar
Schroeder, P.A. Le Golvan, J.J. and Roden, M.F., (2002) Weathering of ilmenite from granite and chlorite schist in the Georgia Piedmont American Mineralogist 87 1616–1625 10.2138/am-2002-11-1211.Google Scholar
Teruggi, M.E. and Kilmurray, J.O. (1975) Tandilia. Relatorio de la Provincia de Buenos Aires, VIoCongreso Geologico Argentino, Bahia Blanca, Argentina, pp. 55–77.Google Scholar
Teruggi, M.E. Kilmurray, J.O. Rapela, C.W. and Dalla Salda, L., (1974) Diques basicos en las Sierras de Tandil Revista de la Asociacion Geologica Argentina XXIX 41–60.Google Scholar
Teruggi, M. Leguizamon, M.A. and Ramos, V.A., (1988) Metamorfitas de bajo grado con afinidades oceanicas en el basamento de Tandil: sus implicaciones geotectonicas, Provincia de Buenos Aires Revista de la Asociaci ó n Geologica Argentina XLIII 366–374.Google Scholar
Valentine, P.C. and Commeau, J.A., (1990) Fine-grained rutile in the Gulf of Maine — Diagenetic origin, source rocks, and sedimentary environment of deposition Economic Geology 85 862–876 10.2113/gsecongeo.85.4.862.Google Scholar
Weaver, C.E., (1989) Clays, Mud, and Shales Amsterdam Elsevier 819 pp.Google Scholar