Characteristic Textures of Recrystallized, Peritectic, and Primary Magmatic Olivine in Experimental Samples and Natural Volcanic Rocks
Résumé
Olivine textures are potentially important recorders of olivine origin and crystallization conditions. Primary magmatic and xenocrystic origins are commonly considered for olivine from ultramafic to intermediate magmas, while secondary olivine origins (i.e. crystals formed by recrystallization or peritectic reaction) are rarely considered in the interpretation of magmatic phenocrysts. The main aim of our study was to determine textures that are characteristic for secondary magmatic olivine and non-characteristic, or at least rare, for primary magmatic olivine. To characterize the textures of the different olivine types, we review previous experimental work and present new textural data for olivine from four melanorite melting and eight basalt crystallization experiments. We (i) qualitatively characterize olivine textures using transmitted light and back-scattered electron microscopy; and (iii) semi-quantitatively characterize the 2D surface area of olivine branches and individual crystals, their 2D and calculated 3D shapes, and 2D grain boundary segment
Domaines
VolcanologieOrigine | Fichiers produits par l'(les) auteur(s) |
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