Nature of quaternary basalts from amanus mountain: Southern part of Turkey

Abstract

Determining basaltic magma sources is easier than felsic magma sources. However, crustal contamination and crystal fractionations cloak important nature and source characteristic of the basaltic magma. To expose this privacy, it is necessary to use different spectroscopic methods to interpret the depth and origins of the intraplate basalts. In this study, Quaternary basalts have a huge outcrop in the southern region of Turkey has benefited from mineral compositions and the chemistry to reveal the origins of these basalts plateau. The basaltic plateau occupies the east and the western parts of Amanus Mountain of southern Turkey. They erupted of very different volcano flats and spread along the plateau-shaped basaltic volcanic interplated with the basaltic volcanic ash in the region. The present studies use the mineral chemistry with the geochemical data to constrain the source and the chemical evolution of the continental intraplate magmas from the Amanus mountain basalts. Two main textural features were exhibited in the basaltic outcrops, an aphanitic texture and a massive texture. Olivine and pyroxenes represent the main mafic component of these basaltic volcanic eruptions. The Confocal Raman Spectroscopy (CRS) studies reveal that, olivines are mostly forsterite and pyroxenes are diopsite and enstatite in compositions. According to the results of the electron microprobe analysis (EPMA) olivines are rich in Mg contents with forsterite and pyroxenes are rich in Ti contents and are in enstatite composites. According to the results of whole rock geochemical analyzes, these basalts exhibit an alkaline nature changing towards the tholeiitic magma nature. Two volcanic phases were classified in the study area. The first phase lavas, characterized by relatively high Si, low Ti and trace-element contents, are consistent with partial melting of a largely peridotitic mantle source. The second phase lavas are more complicated and characterized by a source component depleted in Si and enriched in Ti, Fe, Ca, Mg and P. According to the trace and rare earth element analyzes, the basalts show enrichment of LIL elements and impoverishment of HFS elements during the crystallizations. The tectonic discrimination diagrams, show that the basalts plot on the transition zone from the island arc to the alkaline basalts. Continental crust contaminations with the fractional crystallizations acts as mask in alkaline nature intraplate basalts to plots on the transition zone of alkaline and tholeiitic character bases. © SGEM2018.