Chemo-stratigraphy, petrology and U-Pb geochronology of South-eastern part of the Yuntdag volcano (Karakilicli - Manisa) in Western Anatolia

Abstract

There are a number of volcanic eruption centres that form large caldera structures, and possibly feeding from relatively large magma chambers during the Miocene period in Western Anatolia. One of them is Yuntdag volcano, and its products have formed a thick volcanic succession covering large areas. In this study, an area where the volcanic sequence is seen well in the south-eastern part of the volcano was selected. Geochemistry and geochronology analyses were carried out along a line between Kalpakkaya and camlik Hills in order to better understand the petrological evolution of melting, assimilation, storage and homogenisation processes in the magma chamber (and/or chambers) feeding the volcano within a limited time period (similar to 4 Ma). Samples acquired from the bottom, middle and upper portions of these sections display Early-Middle Miocene ages of 17.64 +/- 0.20, 17.22 +/- 0.15, 16.16 +/- 0.17 and 16.36 +/- 0.13, 15.79 +/- 0.71 and 13.61 +/- 0.20 Ma, respectively. Although, felsic crystal melts, magma mixing and multiple mafic inputs were the dominant processes, fractional crystallisation was less efficient. Also, geochemistry data also indicate that the studied volcanic rocks generated by the melting of the lithospheric mantle, by slab retreat and roll-back of the Hellenic - Cyprus slab, and evolved in shallow magma chambers during the Early - Middle Miocene.