Zeolitization of tuffs at Quinamavida, central southern Chile

Bascuñán S.; Kelm, U; Sanhueza, V; Alfaro G.


Tuffs of the Tertiary Colbún Formation near Quinamávida in central southern 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. Copyright © 2007, The Clay Minerals Society.

Más información

Título según WOS: Zeolitization of tuffs at Quinamavida, central southern Chile
Título según SCOPUS: Zeolitization of tuffs at Quinamávida, central southern Chile
Título de la Revista: Clays and Clay Minerals
Volumen: 55
Número: 5
Fecha de publicación: 2007
Página de inicio: 524
Página final: 533
Idioma: English
URL: http://openurl.ingenta.com/content/xref?genre=article&issn=0009-8604&volume=55&issue=5&spage=524