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 Yuntdağ 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 Çamlık 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 (~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.

摘要

在安纳托利亚西部中新世时期，有许多火山喷发中心形成大型的火山口结构，并可能从相对较大的岩浆室中获取。其中之一是Yuntdağ火山，其产品形成了覆盖大片地区的厚厚的火山岩层序。在这项研究中，选择了在火山东南部火山序列清晰可见的区域。为了更好地了解在有限的时间内为火山提供热量的岩浆室（和/或室）中融化，同化，储存和均质化过程的岩石演化，沿着卡尔帕卡亚山和Çamlık山之间的界线进行了地球化学和年代学分析（〜4 Ma）。从这些部分的底部，中部和上部获取的样品显示中新世的早期年龄为17岁。64±0.20、17.22±0.15、16.16±0.17和16.36±0.13、15.79±0.71和13.61±0.20 Ma。尽管长英质晶体融化，岩浆混合和多个镁铁质输入是主要过程，但分步结晶效率较低。此外，地球化学数据还表明，研究岩石圈地幔融化，平板退缩和希腊-塞浦路斯平板回滚所产生的火山岩，并在中新世中期至中期在浅岩浆室内演化。