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Alteration processes and products of acid pyroclastic rocks in Bulgaria and Slovakia

G. Kirov, E. Samajova, R. Nedialkov and Ts. Stanimirova
Alteration processes and products of acid pyroclastic rocks in Bulgaria and Slovakia (in Zeolite 2010, Ognyan E. Petrov (prefacer) and David L. Bish (prefacer))
Clay Minerals (June 2011) 46 (2): 279-294


The genesis of the products of the alteration of acid pyroclastic material is discussed and interpreted on the basis of the distribution, sedimentation conditions, post-sedimentation activity, mineral and chemical compositions of pyroclastic deposits in Bulgaria and Slovakia. It is found that the disordered nonequilibrium nature of the volcanic glass induces a diagenetic devitrification of the tuffs and formation of clinoptilolitic, adularia-cristobalite and bentonite rocks. With increasing temperature, the volcanic glass tends forward a stable state through a series of zeolite mineral associations: clinoptilolite-mordenite-analcime-feldspar. The change in mineral composition of this series of rocks occurs without a change in the chemical composition of the rocks, which could be explained by the closed nature of zeolite systems. The formation of bentonites is associated with the removal of alkaline ions under diagenetic conditions, while the formation of halloysite rocks is caused by hydrothermal activity.

ISSN: 0009-8558
EISSN: 1471-8030
Serial Title: Clay Minerals
Serial Volume: 46
Serial Issue: 2
Title: Alteration processes and products of acid pyroclastic rocks in Bulgaria and Slovakia
Title: Zeolite 2010
Author(s): Kirov, G.Samajova, E.Nedialkov, R.Stanimirova, Ts.
Author(s): Petrov, Ognyan E.prefacer
Author(s): Bish, David L.prefacer
Affiliation: Sofia University "Saint Kliment Ohridski", Department of Mineralogy, Petrology and Economic Geology, Sofia, Belgium
Affiliation: Bulgarian Academy of Sciences, Institute of Mineralogy and Crystallography, Sofia, Belgium
Pages: 279-294
Published: 201106
Text Language: English
Publisher: Mineralogical Society, London, United Kingdom
Meeting name: 8th international conference on the Occurrence, properties and utilization of natural zeolites (Zeolite 2010)
Meeting location: Sofia, BEL, Belgium
Meeting date: 20100710July 10-18, 2010
References: 34
Accession Number: 2011-073191
Categories: Sedimentary petrology
Document Type: Serial Conference document
Bibliographic Level: Analytic
Illustration Description: illus. incl. 3 plates, 2 tables, sketch maps
N41°30'00" - N44°15'00", E22°15'00" - E28°45'00"
N47°45'00" - N49°40'00", E16°49'00" - E22°30'00"
Secondary Affiliation: Indiana University, USA, United StatesComenius University, BEL, Belgium
Country of Publication: United Kingdom
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, Copyright, Mineralogical Society of Great Britain and Ireland. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201140
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