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Effect of Chemical Pretreatment on X-Ray Powder Diffraction Characteristics of Clay Minerals Derived from Volcanic Ash

Published online by Cambridge University Press:  01 July 2024

Gordon Ross Brewster
Gordon Ross Brewster*
Affiliation:
Department of Geography, The University of Michigan, Ann Arbor, Michigan 48109
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Abstract

The effects of NaOAc removal of carbonates, H2O2 removal of organic materials, and sodium citrate-bicarbonate-dithionite (SCBD) removal of iron oxides upon the X-ray powder diffraction (XRD) characteristics of clay minerals present within weathered volcanic ash deposits were examined. All pretreatments of samples derived from the Ae and Bhf horizons containing volcanic ash resulted in dramatic increases in XRD peak intensities, while the treatment of IIC-horizon samples resulted in subdued XRD peak intensities. Also, the chemical treatments produced an apparent increase in the amount of expandable clay minerals within the Ae horizon, due probably to the hydrolysis and removal of interlayer Al3+ when H2O2 and SCBD were used. Hence, poorly ordered and pedogenically modified vermiculite or vermiculite/montmorillonite interstratifications became “weathered” by H+ attack and Al3+ removal in a manner similar to the natural processes which take place in the acid and eluvial A horizon. In addition, possible XRD peak modification due to the dilution of crystalline clay concentrations by amorphous clay-size material appeared to be subordinate to the laboratory-induced chemical alteration of the weathered clay minerals.

Резюме

Резюме

Изучались воздействия удаления карбонатов с помощью №ОАс, удаления органических материалов с помощью H2O2 и удаления окисей железа с помощью натриевого цитрат-бикарбоната-дитионита (НЦБД) на рентгеновско-дифракционные (РД) характеристеки глинистых минералов, присутствующих в выветренных отложениях вулканического пепла. Все предварительные обработки образцов, отобранных из горизонтов Ae и Bhf, содержащих вулканический пепел, вызывали резкое повышение интенсивностей РД пиков, в то время как обработка образцов из горизонтов ПС вызвало сглаживание РД пиков. Кроме того, химические обработки вызывали явное увеличение количества расширяющихся глинистых минералов в горизонте Ае, вероятно из-за гидролиза и удаления межслойного Al3+ когда использовались H2O2 и НЦБД. Следовательно, плохо упорядоченные и измененные в почвенных условиях вермикулитные или вермикулито/ монтморилонитные перемежающиеся пропласки стали “выветреными” под воздействием H+ и удаления Al3+, т.е. путем, подобным естественным процессам, которые происходят в кислотном и элювиальном горизонте А. К тому же, возможные изменения РД пиков из-за разубоживания кристаллических глинистых концентраций аморфным материалом с размерами, соответствующими глинам, оказались второстепенными по сравнению с индуктированным в лаборатории химическим изменением выветренных глинистых минералов. [N.R.]

Resümee

Resümee

Es wurden die Auswirkungen auf die Röntgendiffraktometer-Charakteristika von—in Vorkommen verwitterter vulkanischer Aschen auftretenden—Tonmineralen untersucht, die entstehen, wenn man Karbonate mit NaOAc, organisches Material mit H2O2, und Eisenoxide mit Natriumcitrat-Bicarbonat-Dithionit (SCBD) entfernt. Alle Vorbehandlungen führen bei den Proben, die aus den vulkanische Asche führenden Ae und Bhf Horizonten stammen, zu einem ungeheuren Anwachsen der XRD-Peakintensitäten. Die Behandlung der Proben aus dem IIC Horizont führt dagegen zu einer Verminderung der XRD-Peakintensitäten. Außerdem bewirken die chemischen Behandlungen, daß der Gehalt an quellfähigen Tonmineralen in Proben des Ae Horizontes sichtbar zunimmt, was wahrscheinlich auf die Hydrolyse und das Entfernen von Zwischenschicht-Aluminium zurückzuführen ist, wenn H2O2 and SCBD verwendet wurden. Daher werden schlecht kristallisierte und durch Bodenbildung beeinflußte Vermiculite und Vermiculit/Montmorillonit-Wechsellagerung durch den H+-Angriff und das Entfernen von Al3+ in einer Art verwittert, die den natürlichen Prozessen äthnlich ist, wie sie in sauren und eluvialen A-Horizonten stattfinden. Auch schien eine mögliche Beeinflussung der XRD-Peaks durch die Verdünnung der Konzentration des Kristallisierten Tons durch amorphes Material von Tongröße der durch die Behandlung bedingten chemischen Veränderung der verwitterten Tonminerale untergeordnet zu sein. [U.W.]

Résumé

Résumé

Les effets sur les caractéristiques XRD des minéraux argileux présents dans des depôts de cendres volcaniques altérées de l'enlèvement par NaOAc de carbonates, par H2O2 de matières organiques, et par dithionite-bicarbonate-citrate de sodium (SCBD) des oxides de fer, out été examinés. Tous les prétraitements d’échantillons dérivés des horizons-Ae et -Bhf contenant de la cendre volcanique ont resulté en un accroissement dramatique des intensités de sommet XRD, tandis que le traitement des échantillons d'horizons-IIC ont resulté en des intensités de sommet XRD amoindries. Il a aussi été remarqué que les traitements chimiques produisaient un accroissement apparent de la quantité de minéraux argileux expansibles dans l'horizon-Ae, sans doute dû à l'hydrolyse et à l'enlèvement de l'inter-couche Al3+ lorsque H2O2 et SCBD étaient employés. Ainsi, la vermiculite ou les interstratifications vermiculite/montmorillonite pauvrement ordonnées ou pédogénicalement modifiées sont devenues “alterées” par l'attaque d'H+ et par l'enlèvement d'Al3+ d'une manière semblable aux procédés naturels qui se passent dans l'horizon-A acide et éluvial. De plus, la modification possible de sommet XRD due à la dilution de concentrations d'argile cristalline par une matière amorphe de taille argileuse semblait être subordonée à l'altération chimique induite dans le laboratoire des minéraux altérés. [D.J.]

Keywords

AmorphousChemical treatmentSoil clayVermiculiteVolcanic ashWeatheringX-ray powder diffraction
Type
Research Article
Information
Clays and Clay Minerals , Volume 28 , Issue 4 , August 1980 , pp. 303 - 310
Copyright
Copyright © Clay Minerals Society 1980

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References

Brewster, G. R., (1979) Genesis of volcanic ash-charged soils having podzolic morphologies, Banff and Jasper National Parks, Alberta: Ph.D. thesis London, Ontario Dept. Geography, Univ. Western Ontario.Google Scholar
Brown, G., (1961) The X-ray Identification and Crystal Structures of Clay Minerals London Mineralogical Society.Google Scholar
Canada Soil Survey Committee, 1978 The Canadian System of Soil Classification Ottawa, Ontario Canada Dept. Agri. Publ. 1646, Supply and Services Canada.Google Scholar
Crandell, D. R. Mullineaux, D. R. Miller, R. D. and Rubin, M., (1962) Pyroclastic deposits of Recent age at Mount Rainier, Washington U.S. Geol. Surv. Prof. Pap. 450 64–68.Google Scholar
Douglas, L. A. and Fiessinger, F., (1971) Degradation of clay minerals by H2O2 treatments to oxidize organic matter Clays & Clay Minerals 19 67–68.CrossRefGoogle Scholar
Fryxell, R., (1965) Mazama and Glacier Peak volcanic ash layers, relative ages Science 147 1288–1290.CrossRefGoogle ScholarPubMed
Gibbs, R. J., (1967) Quantitative X-ray diffraction analysis using clay mineral standards extracted from the samples to be analyzed Clay Miner. 7 79–90.CrossRefGoogle Scholar
Harward, M. E. and Theisen, A. A., (1962) Problems in clay mineral identification by X-ray diffraction Soil Sci. Soc. Amer. Proc. 26 335–341.CrossRefGoogle Scholar
Harward, M. E. Theisen, A. A. and Evans, D. D., (1962) Effect of iron removal and dispersion methods on clay mineral identification by X-ray diffraction Soil Sci. Soc. Amer. Proc. 26 535–541.CrossRefGoogle Scholar
Jackson, M. L., (1973) Soil Chemical Analysis, Advanced Course 2nd Wisconsin Publ, by the author, Dept. Soil Science, Univ. Wise, Madison.Google Scholar
Kinter, E. B. and Diamond, S., (1956) A new method for the preparation and treatment of oriented specimens of soil clay for X-ray diffraction analysis Soil Sci. 81 111–120.CrossRefGoogle Scholar
McKyes, E. Sethi, A. and Yong, R. N., (1974) Amorphous coatings on particles of sensitive clay soils Clays & Clay Minerals 22 427–433.CrossRefGoogle Scholar
Mehra, O. P. Jackson, M. L. and Swineford, A., (1960) Iron oxide removal from soils and clays by a dithionite-citrate system buffered with sodium bicarbonate Clays and Clay Minerals, Proc. 7th Nat. Conf., Washington, D.C., 1958 New York Pergamon Press 317–327.Google Scholar
Nasmith, H. Mathews, W. H. and Rouse, G. E., (1967) Bridge River ash and some Recent ash beds in British Columbia Can. J. Soil Sci. 4 163–170.Google Scholar
Rich, C. I., (1969) Suction apparatus for mounting clay specimens on ceramic tile for X-ray diffraction Soil Sci. Soc. Amer. Proc. 33 815–816.CrossRefGoogle Scholar
Rich, C. I., (1975) Amount of clay needed for optimum X-ray diffraction analysis Soil Sci. Soc. Amer. Proc. 39 161–162.CrossRefGoogle Scholar
Rutter, N. W., (1972) Geomorphology and multiple glaciation in the area of Banff, Alberta Geol. Surv. Can. Bull. 206 1–54.Google Scholar
Townsend, F. C. and Reed, L. W., (1971) Effects of amorphous constituents on some mineralogical and chemical properties of a Panamanian latosol Clays & Clay Minerals 19 303–310.CrossRefGoogle Scholar