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A new massive deposit of allophane raw material in Ecuador

Published online by Cambridge University Press:  01 January 2024

Stephan Kaufhold ,
Annette Kaufhold ,
Reinhold Jahn ,
Salomón Brito ,
Reiner Dohrmann ,
Rainer Hoffmann ,
Hartmut Gliemann ,
Peter Weidler  and
Manfred Frechen
Stephan Kaufhold*
Affiliation:
BGR, Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, D-30655 Hannover, Germany
Annette Kaufhold
Affiliation:
Martin-Luther-University Halle-Wittenberg, Institute for Soil Sciences and Plant Nutrition, Weidenplan 14, D-06108 Halle, Germany
Reinhold Jahn
Affiliation:
Martin-Luther-University Halle-Wittenberg, Institute for Soil Sciences and Plant Nutrition, Weidenplan 14, D-06108 Halle, Germany
Salomón Brito
Affiliation:
SGN, Servicio Geológico Nacional, Juan León Mera y Orellana (esquina), Quito, Ecuador
Reiner Dohrmann
Affiliation:
BGR, Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, D-30655 Hannover, Germany LBEG, Landesamt für Bergbau, Energie und Geologie, Stilleweg 2, D-30655 Hannover, Germany
Rainer Hoffmann
Affiliation:
BGR, Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, D-30655 Hannover, Germany
Hartmut Gliemann
Affiliation:
ITC-WGT, Abteilung Nanomineralogie, Forschungszentrum Karlsruhe, Forschungszentrum Karlsruhe GmbH, Herman-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
Peter Weidler
Affiliation:
ITC-WGT, Abteilung Nanomineralogie, Forschungszentrum Karlsruhe, Forschungszentrum Karlsruhe GmbH, Herman-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
Manfred Frechen
Affiliation:
GGA, Institut für Geowissenschaftliche Gemeinschaftsaufgaben, Stilleweg 2, D-30655 Hannover, Germany
*
* E-mail address of corresponding author: s.kaufhold@bgr.de
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Abstract

In Ecuador, DINAGE (known today as the Servicio Geológico Nacional) and the German Federal Institute for Geosciences and Natural Resources have discovered a huge allophane deposit covering an area of >4000 km2. This study presents the results from an investigation of a 16-m thick vertical sequence from this deposit, supposedly the weathering product of two different volcanic ash deposits. In particular, the distribution of alkali metals within the uppermost layer indicates that the weathering process is still ongoing.

According to the mineralogical composition, an allophane-rich layer (allophane facies) could be distinguished from the underlying halloysite-rich layer (halloysite facies). A 2-m thick transition zone is characterized by the presence of gibbsite and intermediate specific surface area values. Only a few imogolite fibers could be identified (by scanning electron microscopy), indicating the dominance of allophane over imogolite in the allophane facies. Single allophane particles were investigated by atomic force microscopy, though this method was less accurate than transmission electron microscopy with respect to the determination of the primary particle diameter. Carbon isotope analysis (14C) suggested an age of ∼20,000 y for the allophane layer.

Within the allophane facies, a 4-m thick layer occurs containing 70–80 wt.% allophane with an N2-BET specific surface area of >300 m2/g. Based on infrared and energy-dispersive X-ray diffraction measurements, an Al/Si ratio of 1.3–1.4 was established for this allophane, which is between Al-rich and Si-rich allophane. The allophane layer may be of economic value due to the large allophane content, the small amount of organic matter, and the significant thickness of the deposit.

Keywords

AFMAllophaneEcuadorNanoparticleSpecial Clay
Type
Article
Information
Clays and Clay Minerals , Volume 57 , Issue 1 , February 2009 , pp. 72 - 81
Copyright
Copyright © The Clay Minerals Society 2009

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References

Benbow, J., 1990 New Zealand’s minerals for domestic consumption Industrial Minerals 273 19–35.Google Scholar
Blakemore, L.C., Searle, P.L., and Daly, B.K. (1981) Methods for Chemical Analysis of Soils. New Zealand Soil Bureau, Department of Scientific and Industrial Research, Report 10A, New Zealand.Google Scholar
Dohrmann, R. Meyer, I. Kaufhold, S. Jahn, R. Kleber, M. and Kasbohm, J., 2002 Rietveld based-quantification of allophane Mainzer Naturwissenschaftliches Archiv 40 28–30.Google Scholar
FAO-UNESCO (1971) Soil map of the world 1:5,000,000. Vol. IV — South America. Paris.Google Scholar
Farmer, V.C. Fraser, A.R. Russell, J.D. and Yoshinaga, N., 1977 Recognition of imogolite structures in allophanic clay by infrared spectroscopy Clay Minerals 12 55–57 10.1180/claymin.1977.012.1.04.CrossRefGoogle Scholar
Geyh, M.A., 2005 14C dating — still a challenge for users? Zeitschrift für Geomorphologie N.F. 139 63–86.Google Scholar
Harsh, J. and Sumner, M.E., 2000 Poorly crystalline aluminosilicate clays Handbook of Soil Science Boca Raton, Florida, USA CRC Press F169–F182.Google Scholar
Harsh, J. Chorover, J. Nizeyimana, E. and Dick, W.A., 2002 Allophane and Imogolite Soil Mineralogy with Environmental Applications Madison, Wisconsin, USA Soil Science Society of America 291–322.Google Scholar
Henmi, T. and Wada, K., 1976 Morphology and composition of allophane American Mineralogist 61 379–390.Google Scholar
Kaufhold, S. (2007) Ecuadorian Allophane. Industrial Minerals, May 2007, p. 95.Google Scholar
Kaufhold, S., Zeisig, A., Jahn, R., Dohrmann, R., and Brito, S. (2007a) Allophane from Ecuador. CMS Annual meeting in Santa Fe, Program and abstracts, p. 108. Available online at: .Google Scholar
Kaufhold, A. Dohrmann, R. and Jahn, R., 2007 Einfluss der Trocknung auf die Eigenschaften von Allophan DBG Mitteilungen 110 2 647–648 ISSN 0343-1071.Google Scholar
Parfitt, R.L., 1990 Allophane in New Zealand — A Review Australian Journal of Soil Research 28 343–360 10.1071/SR9900343.CrossRefGoogle Scholar
van der Gaast, S.J. Wada, K. Wada, S.I. and Kakuto, Y., 1985 Small-angle X-ray powder diffraction, morphology, and structure of allophane and imogolite Clays and Clay Minerals 33 237–243 10.1346/CCMN.1985.0330310.CrossRefGoogle Scholar
Wada, K., Dixon, J.B. and Weed, S.B., 1989 Allophane and imogolite Minerals in Soil Environments Madison, Wisconsin, USA Soil Science Society of America 1051–1087.Google Scholar
Wells, N. Childs, C.W. and Downes, C.J., 1977 Silica springs, Tongariro national park, New Zealand — analyses of the spring water and characterization of the aluminosilicate deposit Geochmica et Cosmochimica Acta 41 1497–1506 10.1016/0016-7037(77)90254-X.CrossRefGoogle Scholar
Yuan, G., 2004 Environmental nanomaterials: Occurrence, syntheses, characterization, health effect, and potential applications Journal of Environmental Science and Health, Part A — Toxic/Hazardous Substances & Environmental Engineering A39 2545–2548 10.1081/ESE-200027009.Google Scholar
Zeisig, A., Schöneich, S., Kaufhold, S., Dohrmann, R., and Jahn, R. (2004) Allophanreicher Ton — ein ‘special clay’ aus Ecuador. Pp. 103–104 in: Berichte der DTTG, 10, (Nüesch, R. and Emmerich, K., editors). Karlsruhe, ISSN 1432-7007, available online at .Google Scholar
Zeisig, A., Jahn, R., Dohrmann, R. and Kaufhold, S. (2005) Allophane rich clay — a special clay from Santo Domingo de los Colorados/Ecuador, characterisation and potential application. Pp. 99–104 in: Berichte der DTTG, Celle, 11 (Dohrmann, R. and Kaufhold, S., editors). ISSN 1432-7007, available online at .Google Scholar