K-Feldspar Phenocrysts from Tertiary Igneous Rocks from Samothrace Island (N. Aegean,Greece): Chemical Zoning and XRD Analysis (original) (raw)

Abstract

Zoned Κ-feldspar phenocrysts from Samothraki Island tertiary plutonic and volcanic rocks have been subjected to optical, chemical and XRD analysis. Geochemical data have indicated an increasing trend of Al, Na and Ba from margin to core of the phenocrysts, while Si and K decrease towards the same direction. The statistical processing of chemical data revealed that cation distribution in the various zones is not of the same intensity for every element. Specifically, the greater variation is presented by Ba cations followed by Na. Moreover, XRD analysis shows differentiation of lattice parameters in each zone and a decreasing trend of lattice cell volume from crystal margin to the core. Finally, the calculated temperatures at which the crystal ordering of Si/Al is completed, indicate that magma crystallization has not been normal, since ordering has shown an increasing trend from core to margin.

Georgios Christofides hasn't uploaded this paper.

Let Georgios know you want this paper to be uploaded.

Ask for this paper to be uploaded.