Clays and Clay Minerals, Vol. 55, No. 5, 524–533, 2007.
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Authors
Bascun˜an, Sophi´a
Kelm, Ursula
Sanhueza, Vilma
Alfaro, Guillermo
Issue Date
2007
Type
Article
Language
Keywords
Periodicals , Geology , Chile , Heulandite , Clinoptilolite , Mordenite , Tuff , Zeolite
Alternative Title
Zeolitization Of Tuffs At Quinama´vida, Central Southern Chile
Abstract
Tuffs of the Tertiary Colbu´n Formation near Quinama´vida in central so uthern Chile have been mapped and their mineralogy analyzed. The pyroclastic rocks present a maximum outcropping thickness of 120 m and are dominated by vitreous lapilli and minor lithic tuffs, the products of active volcanism nearby. About 10% of the tuffs consist of lenses of fine banded tuffs with a high leaf content that were deposited in shallow lakes during quiescent periods between periods of volcanic activity. This tuff sequence is pervasively transformed to clinoptilolite/heulandite and mordenite with variable amounts of plagioclase, minor quartz and smectite. Factors thought to have influenced this conversion to zeolites are a humid climate following deposition combined with a slightly elevated heat flow. Local hydrogeological conditions have modified the cation-hydrogen ion ratios across the study area favoring the formation of clinoptilolite/heulandite and mordenite with medium-minor smectite in the center and south, and a more abundant presence of smectite in the north of the study area.
Description
Clays and Clay Minerals, Vol. 55, No. 5, 524–533, 2007. Zeolitization Of Tuffs At Quinama´vida, Central Southern Chile. Sophi´a Bascun˜an; Ursula Kelm; Vilma Sanhueza; Guillermo Alfaro. DOI: 10.1346/CCMN.2007.0550507. Copyright © 2007, The Clay Minerals Society
Citation
Clays and Clay Minerals, Vol. 55, No. 5, 524–533, 2007.
Publisher
The Clay Minerals Society
License
Copyright © 2006-2018, The Clay Minerals Society