Major and Trace Element Chemistry of Chromian Spinels in Peridotites from Yesilova Ophiolite (SW Turkey): Petrogenetic Interpretation

The Yesilova ophiolite is one of the most important tectonic unit represented the western part of the ophiolite belts of the Anatolide-Tauride block, SW Turkey. In this study, we discussed the harzburgite-dunite suite in the mantle sequence of this ophiolite using the mineral chemistry of the chromian spinels. On the basis of the Cr# and Mg# values, the spinels in the harzburgite and dunite are similar to those from fore-arc peridotites. The relatively high-Cr# and low-Ti contents of the chromian spinels in the harzburgite signify that they belong to a supra-subduction setting. However, the Cr#-TiO₂ relationships in the chromian spinels from the dunite favor a melt-rock interaction model in which dunite with relatively high-Al and high-Ti spinels were produced by the interaction of harzburgite with MORB-like melt. Also, this study uses Laser Ablation–Inductively Coupled Plasma–Mass Spectrometry (LA–ICP–MS) to better understand the relationship between the harzburgite and dunite based on the chromian spinel chemistry. The trace element concentrations of the spinels show that Ga, Ni, V, Zn, Co contents decrease, and Sc, Ti, Mn and LREE contents increase from the harzburgite to the dunite, suggesting a control by partial melting, and all studied chromian spinels reveal a subduction zone environment.