Hostname: page-component-77c89778f8-gq7q9 Total loading time: 0 Render date: 2024-07-16T23:08:38.220Z Has data issue: false hasContentIssue false

The Origin of Pyrophyllite Rectorite in Shales of North Central Utah

Published online by Cambridge University Press:  01 July 2024

G. V. Henderson*
Affiliation:
Department of Earth Sciences, California State Polytechnic College, Pomona, Calif. 91766

Abstract

Pyrophyllite is widespread in pelitic rocks of the Manning Canyon Shale in north central Utah, and the association of this mineral with other clay minerals, especially rectorite is related to the origin. The regular mixed-layer clay mineral rectorite seems to form as a result of the alteration of muscovite-paragonite during late stages of diagenesis and represents an intermediate metastable phase in the mineral paragenetic sequence. Pyrophyllite subsequently formed from the alteration of rectorite during advancing metamorphism and is the stable end member of the clay mineral assemblage.

Structural interpretations of rectorite found in the Manning Canyon Shale shows a regular, alternating sequence which consists of a fixed layer of 9.6 Å and an expandable layer, varying from 10 Å to 17 Å. With ethylene glycol saturation in the natural state a basal reflection of 26.60 Å is recorded.

Résumé

Résumé

La pyrophyllite est très répandue dans les roches pélitiques du schiste de Manning Canyon, au centre-nord de l’Utah, et l’association de ce minéral avec d’autres minéraux argileux, en particulier la rectorite, est lié à l’origine. La rectorite régulière interstratifié de minéraux argileux semble se former par suite de la modification de la muscovite-paragonite au cours des derniers stades de la diagénèse et représente une phase métastable intermédiaire dans la séquence paragénétique des minéraux. La pyrophyllite s’est donc formée par suite de la modification de la rectorite au cours du métamorphisme avancé et représente la partie stable en bout de l’assemblage des minéraux argileux.

Les interprétations de structure de la rectorite découverte dans le schiste du Manning Canyon montre une séquence régulière, alternée qui consiste en une couche fixe de 9,6 Å et une couche extensible, variant de 10 Å à 17 Å. Avec la saturation d’éthylène glycol à l’état naturel, une réflexion basale de 26,60 A est enregistrée.

Kurzreferat

Kurzreferat

Pyrophyllit ist weitverbreitet in pelitischem Gestein der Manning Canyon Schiefer im nördlichen Zentral-Utah. une die Verbindung dieses Minerals mit anderen Tonge-steinen, besonders Rectorit, steht in Zusammenhang mit dem Ursprung. Das regulär mischgeschichtete Tongestein Rectorit scheint sich als Ergebnis der Abwechslung von Muskowit-Paragonit während der späteren Phasen der Diagenese zu bilden und stellt eine metastabile Zwischenstufe in der paragenetischen Folge des Gesteins dar. Der Pyrophyllit hat sich in der Folge durch Veränderung von Rectorit während fortschreitendem Metamorphismus gebildet und stellt das stabile Endglied des Tonmineral Zusammenbaus dar.

Die strukturelle Bestimmung des im Manning Canyon Schiefer gefundenen Rectorit zeigt eine reguläre, abwechselnde Folge, die aus einer festen Schicht von 9.6 Å und einer aufblähbaren Schicht, die zwischen 10 Å und 17 Å schwankt. Bei Äthylenglykol-Sättigung im natüralichen Zustand wird eine basale Reflexion von 26.60 Å verzeichnet.

Резюме

Резюме

Пирофиллит широко распространен в пелитовых породах толщи Мэннинг-Каньон Шэйл на севере центральной уасти шт. Юта; ассоциация этого минерала с другими глинистыми минералами, в особенности с ректоритом, зависит от их генезиса. Упорядоченный смешанно-слойный глинистый минерал ректорит, по-видимому, образуется при изменении мусковита-парагонита на поздних стадиях диагенеза и представляет собой промежуточную метастабил-ьную фазу парагенетического ряда минералов. Пирофиллит образуется при изменении ректорита в процессе прогрессивного метаморфизма и является стабильным конечным членом ассоциации глинистых минералов.

Структурные исследования ректорита, обнаруженного в толще Мэннинг-Каньон Шэйл, выявили регулярное чередование слоев двух типов: неразбухающих с d001 9,6А и разбухающих с d001 от 10А до 17А. При насыщении этилен-гликолем ректорит дает базальный рефлеск 26, 60А.

Type
Research Article
Copyright
Copyright © 1970 The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bailey, S. W. (1966) The status of clay mineral structures: Clays and Clay Minerals 14, 113.CrossRefGoogle Scholar
Beuf, S., Biju-Duval, B., Stevaus, J. and Kulbieki, G. (1966) Ampleur des Glaciations “Siluriennes” au Sahara: Leurs Influences et Leurs Consequences sur la Sedimentation: Rev. Inst. Franc. Petrole 21, 363381.Google Scholar
Biscaye, P. E. (1965) Mineralogy and sedimentation of recent deep sea clay in the Atlantic Ocean and adjacent seas and oceans: G eoi. Soc. A m. Bull. 76 803832.CrossRefGoogle Scholar
Bradley, W. F. (1951) The alternating layer sequence of rectorite: Am Mineralogist 35, 590595.Google Scholar
Brindley, G. W. (1956) Allevardite, a swelling double- layer mica mineral: Am. Mineralogist, 41, 91103.Google Scholar
Brown, G. (1961) The X-ray identification and crystal structures of clay minerals: Min. Soc. London .Google Scholar
Cole, W. F. (1966) A study of a long-spacing mica-like mineral: Clay Minerals 6. 261.Google Scholar
Condie, K. C. (1967) Petrology of the late precambrian tillite association in northern Utah: Geol. Soc. Am., Bull. Vol. 78, pp. 13171344.CrossRefGoogle Scholar
Crawford, A. L. and Buranek, A. M. (1948) A reconnaissance of the geology and mineral deposits of the lake mountains, Utah County, Utah: Utah Geol. and Min. Surv., Circ. 35, 33 pp.Google Scholar
Ehlmann, A. J. (1958) Pyrophyllite in Shales of North Central Utah: Utah Eng. Exp. Sta., Bull. no. 94, 103 p.Google Scholar
Eskola, P. (1939) Die Entstehung der Gesteine in (Barth, Cormes, Eskola) Springer, Berlin, pp. 375392.Google Scholar
Eugster, H. P. and Yoder, H. S. (1955) The join mus- covite-paragonite: Carnegie Inst. Wash. Yearbook, Vol. 55, pp. 124126.Google Scholar
Goldschmidt, V. M. (1922) On the metasomatic processes in silicate rocks: Econ. Geol. 17, 105132.CrossRefGoogle Scholar
Hamilton, J. D. (1967) Partially-ordered mixed layer mica-montmorillonite from Maitland, New South Wales: Clay Minerals 7, 63.CrossRefGoogle Scholar
Henderson, G. V. (1968) Pyrophyllite-bearing clay in Clinton Deposit, Utah County, Utah: Utah Geol. and Min. Survey, Special Studies, no. 23, 28 pp.Google Scholar
Henderson, G. V. and Bradley, W. F. (1970) Rectorite and the rectorite-like layer structures, Clays and Clay Minerals, 18, 115119.10.1346/CCMN.1970.0180207CrossRefGoogle Scholar
Hyatt, E. P. (1956) Clays of Utah County, Utah: Utah Geol. and Min. Survey, Bull. 55, 83 pp.Google Scholar
Kodarna, H. (1958) Mineralogical study of some pyrophyllites in Japan: Mineral J. (Japan) 2, 236244.Google Scholar
Millot, G. (1964) Geologie des Argiles. Masson, Paris.Google Scholar
Moyle, R. W. (1959) Manning Canyon Shale: Utah Geol. Soc., Guidebook to the Geology of Utah: no. 14, pp. 5992.Google Scholar
Roy, R. and Osborne, E. F. (1954) The System A12O3-SiO2-20O: Am. Mineralogist 39. 53855.Google Scholar
Tornita, K. and Sudo, T. (1968) Conversion of Mica into an Interstratified Mineral, Reports of the Faculty of Sei., Kagoshima Univ. 1, 89110.Google Scholar
Veide, B. (1968) The effect of chemical reduction on the stability of pyrophyllite and kaolonite in pelitic rocks: J. Sediment Petrol. 38. 1316.Google Scholar
Zen, E.-An. (1962) Problem of the thermodynamic status of the mixed-layer minerals: Geochim. Cosmochim. Acta 26, 10551068.CrossRefGoogle Scholar
Zen, E-an and Albee, A. L. (1964) Coexistant Muscovite and Paragonite in Peletic Schists, Am. Mineralogist 49, 904926.Google Scholar