Los piroxenos de las rocas graníticas de la Sierra de Guadarrama (S.C.E.)

The pyroxenes are rarely observed in the granitic rocks from the Sierra de Guadarrama. The clinopyroxene only exists in the basic-intermediate types of cafemic calc-alkaline associations ( El Tiemblo, Almenara, Ventosilla, etc); in the granodiorites from alumino-cafemic monzonitic associations ( Nav...

Descripción completa

Detalles Bibliográficos
Autor: Casillas Fernández, R.
Tipo de recurso: artículo
Fecha de publicación:1993
País:España
Institución:Universidad de Huelva (UHU)
Repositorio:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Idioma:español
OAI Identifier:oai:ariasmontano.uhu.es:10272/14047
Acceso en línea:http://hdl.handle.net/10272/14047
Access Level:acceso abierto
Palabra clave:Pyroxenes
Granitic rocks
Sierra de Guadarrama
Formation conditions
Subsolidus reequilibrium
Descripción
Sumario:The pyroxenes are rarely observed in the granitic rocks from the Sierra de Guadarrama. The clinopyroxene only exists in the basic-intermediate types of cafemic calc-alkaline associations ( El Tiemblo, Almenara, Ventosilla, etc); in the granodiorites from alumino-cafemic monzonitic associations ( Navas del Marqués and La Cabrera ), or in the enclaves included in these rocks. Only in the Ventosilla pluton is also possible to find ortopyroxene crystals. The geochemical study of these phases allows the determination of different conditions of formation of these minerals: f02, Tª, etc, in the various granitic types. In some occasions and possibly by slow cooling rate of the plutonio masses, the crystals of clinopyroxene present granule exolution and subsolidus reequilibrium