%0 Journal Article
%T PETROGRAF¨ªA Y GEOQU¨ªMICA DE LAS ROCAS ANCESTRALES DEL VOLC¨¢N NEVADO DEL RUIZ
%A Toro Toro
%A Luz Mary
%A Borrero-Pe£¿a
%A Carlos Alberto
%A Ayala Carmona
%A Luis Fernando
%J Boletin de Geolog¨ªa
%D 2010
%I Scientific Electronic Library Online
%X a model of the "ruiz ancestral" stage (2 to 1 ma) at the nevado del ruiz volcano is proposed. the extension of the lava remnants of this stage covered an area of about 200 km2 and they were cartographied around the northeast-north-northwest of the present edifice of the volcano. whole-rock geochemical data of andesitic, basaltic-andesitic and dacitic samples from the different outcrops share the calcalkaline affinity with medium to high k contents. the trace elements range variation compared with sio2 suggests a fractional crystallization mechanism from the ferromagnesian minerals and the calcic plagioclase. the trace elements pattern is typical of a volcanic arc with sr, k, rb, ba y th enrichments and nb impoverishment. the ree diagram shows a smooth slope and the typical lree enrichment.
%K ancestral ruiz
%K volcanic arc
%K andesites
%K calcalkaline
%K colombia.
%U http://www.scielo.org.co/scielo.php?script=sci_abstract&pid=S0120-02832010000100005&lng=en&nrm=iso&tlng=en