Open    Access



Microstructure and Mineralogic Evidences of Fractional Differentiation: The Yeşilova Ophiolite Example



Author(s)

Ayşe Didem KILIÇ

Full-Text PDF XML     1001 Views

DOI:10.17265/2159-581X/2017.01.004

The Yesilova ophiolite located in the Alpine zone. This work deals with differentiation mechanism of ultramafic cumulate in ophiolite. Generally, the sequence consists of gabbro and plagiogranite. The petrographic and petrolgichal properties of it show that the layering in gabbros are products of a differentiation by fractional crystallization insitu. Because it has ferrous compounds (magnetite, hematite) by means of volatiles (H₂O, CO₂) that evidence magma at high temperatures (>700 °C). Ferrous liquids are compatible with fractional crystallization through olivine, plagioclase, clinopyroxene removal; whereas the evolved gabbros represent clinopyroxene, plagioclase cumulates from ferrous liquids with little amounts of trapped melt. Furthermore, cathodo luminesans image of zircons shows chemichal characteristic of oceanic plagiogranit (such as Fe₂O₃/MgO, Rb, Sr, Zr,TiO₂) that these characters can be explained by fractional crystallization processes in the late stage of magma generation. Furthermore, all plagiogranites have small positive Eu anomalies indicating the significant role of plagioclase in the fractional crystallization. So, the Yeşilova ophiolite ultramafic cumulates are the most probably related to crystal-liquid fractionation process of the oceanic crust of the Alpine belt. The plagiogranite is differentiation products of crystal-liquid insitu of a mafic magma in the magma chamber.

Crystal-liquid fractionation, SW-Turkey, plagiogranite, gabbros.