Mineralogy of calcic zeolites and mafic phyllosilicates. characteristic of hydrothermal metamorphism in Paleogene volcanic rocks from Lago Hermoso to Río Traful, Neuquén

Using a combination of morphological, optical and microprobe data, thermal analyses and XRD, a sequence of calcic zeolites and a progressive sequence of mafic phyllosilicates from smectite to mixed-layer smectite/chlorite have been identified in metavolcanic rocks affected by low grade hydrothermal...

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Detalles Bibliográficos
Publicado: 1996
Materias:
geothermal system
phyllosilicate
zeolite
Argentina, Neuquen Province
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v51_n3_p235_VattuoneDePonti
http://hdl.handle.net/20.500.12110/paper_00044822_v51_n3_p235_VattuoneDePonti
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00044822_v51_n3_p235_VattuoneDePonti
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spelling paper:paper_00044822_v51_n3_p235_VattuoneDePonti2023-06-08T14:25:14Z Mineralogy of calcic zeolites and mafic phyllosilicates. characteristic of hydrothermal metamorphism in Paleogene volcanic rocks from Lago Hermoso to Río Traful, Neuquén geothermal system phyllosilicate zeolite Argentina, Neuquen Province Using a combination of morphological, optical and microprobe data, thermal analyses and XRD, a sequence of calcic zeolites and a progressive sequence of mafic phyllosilicates from smectite to mixed-layer smectite/chlorite have been identified in metavolcanic rocks affected by low grade hydrothermal metamorphism in Paso del Córdoba, Neuquén. The zeolites are: laumontite, yugawaralite, wairakite, heulandite, stilbite, stellerite and chabazite. Some of these calcic zeolites are characteristic of a high geothermal gradient hydrothermal metamorphism. The alteration of the andesitic and basaltic host rocks may cause the release of Ca, Mg and Fe ions to the interstitial solution from which Ca zeolites and mafic phyllosilicates were precipitated. High activities of Ca and reduced PCO2 operated in favour of the formation of calcic zeolites without interfering with the formation of phyllosilicates. The phyllosilicates are: 1)Mixtures of di- and trioctahedral smectites that predominate below temperatures of aproximately 200° C and 2) trioctahedral smectites and mixed layer chlorite/smectite of high temperature (>200° C) origin. Analytical electron microscope data shows that prograde changes in composition produced loss of Ca, Si and Fe. Contents of AlIV increase systematically with temperature from smectite to chlorite/smectite. The highest metamorphic temperatures, of about 250° C/260° C were reached in the meta-andesites near the Río Córdoba, as indicated by the association with laumontite, wairakite and mixed-layer chlorite/smectite. These temperatures, seem to be lower (about 200° C) in the northwest, where metabasalts with yugawaralite, wairakite, heulandite and smectites occur. 1996 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v51_n3_p235_VattuoneDePonti http://hdl.handle.net/20.500.12110/paper_00044822_v51_n3_p235_VattuoneDePonti
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic geothermal system
phyllosilicate
zeolite
Argentina, Neuquen Province
spellingShingle geothermal system
phyllosilicate
zeolite
Argentina, Neuquen Province
Mineralogy of calcic zeolites and mafic phyllosilicates. characteristic of hydrothermal metamorphism in Paleogene volcanic rocks from Lago Hermoso to Río Traful, Neuquén
topic_facet geothermal system
phyllosilicate
zeolite
Argentina, Neuquen Province
description Using a combination of morphological, optical and microprobe data, thermal analyses and XRD, a sequence of calcic zeolites and a progressive sequence of mafic phyllosilicates from smectite to mixed-layer smectite/chlorite have been identified in metavolcanic rocks affected by low grade hydrothermal metamorphism in Paso del Córdoba, Neuquén. The zeolites are: laumontite, yugawaralite, wairakite, heulandite, stilbite, stellerite and chabazite. Some of these calcic zeolites are characteristic of a high geothermal gradient hydrothermal metamorphism. The alteration of the andesitic and basaltic host rocks may cause the release of Ca, Mg and Fe ions to the interstitial solution from which Ca zeolites and mafic phyllosilicates were precipitated. High activities of Ca and reduced PCO2 operated in favour of the formation of calcic zeolites without interfering with the formation of phyllosilicates. The phyllosilicates are: 1)Mixtures of di- and trioctahedral smectites that predominate below temperatures of aproximately 200° C and 2) trioctahedral smectites and mixed layer chlorite/smectite of high temperature (>200° C) origin. Analytical electron microscope data shows that prograde changes in composition produced loss of Ca, Si and Fe. Contents of AlIV increase systematically with temperature from smectite to chlorite/smectite. The highest metamorphic temperatures, of about 250° C/260° C were reached in the meta-andesites near the Río Córdoba, as indicated by the association with laumontite, wairakite and mixed-layer chlorite/smectite. These temperatures, seem to be lower (about 200° C) in the northwest, where metabasalts with yugawaralite, wairakite, heulandite and smectites occur.
title Mineralogy of calcic zeolites and mafic phyllosilicates. characteristic of hydrothermal metamorphism in Paleogene volcanic rocks from Lago Hermoso to Río Traful, Neuquén
title_short Mineralogy of calcic zeolites and mafic phyllosilicates. characteristic of hydrothermal metamorphism in Paleogene volcanic rocks from Lago Hermoso to Río Traful, Neuquén
title_full Mineralogy of calcic zeolites and mafic phyllosilicates. characteristic of hydrothermal metamorphism in Paleogene volcanic rocks from Lago Hermoso to Río Traful, Neuquén
title_fullStr Mineralogy of calcic zeolites and mafic phyllosilicates. characteristic of hydrothermal metamorphism in Paleogene volcanic rocks from Lago Hermoso to Río Traful, Neuquén
title_full_unstemmed Mineralogy of calcic zeolites and mafic phyllosilicates. characteristic of hydrothermal metamorphism in Paleogene volcanic rocks from Lago Hermoso to Río Traful, Neuquén
title_sort mineralogy of calcic zeolites and mafic phyllosilicates. characteristic of hydrothermal metamorphism in paleogene volcanic rocks from lago hermoso to río traful, neuquén
publishDate 1996
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v51_n3_p235_VattuoneDePonti
http://hdl.handle.net/20.500.12110/paper_00044822_v51_n3_p235_VattuoneDePonti
_version_ 1768546700987727872

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