Please use this identifier to cite or link to this item: http://dspace.mediu.edu.my:8181/xmlui/handle/10261/3209
Title: Origine des grenats des roches calco-alcalines du Sud-Est de l'Espagne
Keywords: Calc-alkaline rocks
dacites - rhyodacites
garnets almandine
SE Spain
Publisher: Springer
Description: Los auteurs remercient le docteur V. ARAÑA de l'Institut Lucas Mallada (C.S.I.C.) la lecture critique du manuscrit. Le docteur F. DIMANCHE de l'Université de Liége a réalisé la traduction en français du travail.
Tertiary dacites and rhyodacites in SE Spain contain garnets, both as phenocrysts in the lavas and within their enclosed metamorphic xenoliths. Microprobe analyses show that calc-alkaline and metamorphic rocks garnets are quite similar in composition (almandine-rich). However, the zoning patterns displayed in the two types of garnets differ. Garnets included in lavas show normal zoning (or a slight enrichment of Mn at the borders), while garnets in xenoliths have Mn-enriched rims or reverse zoning. The differences in zonation, as well as in petrographic features, indicate that the garnets in volcanic rocks crystallized directly from the calc-alkaline magma at an early stage of its crystallization. On the other hand, the uniform composition of dacitic and rhyodacitic garnets, as well as its low pyrope and grossular content, suggest that the conditions in which the garnets crystallized were rapidly exceeded.
"Instituto Lucas Mallada" (C.S.I.C.)
Peer reviewed
URI: http://dspace.mediu.edu.my:8181/xmlui/handle/10261/3209
Other Identifiers: Bulletin of Volcanology Volume 40, Number 3 1-12
0366-483X
http://hdl.handle.net/10261/3209
10.1007/BF02596996
Appears in Collections:Digital Csic

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