Alpine metamorphism of the Pan-African gneiss basement in the Menderes Massif, SW-Turkey. New constraints from Lu-Hf and Sm-Nd garnet geochronology.

本研究将利用Lu-Hf和Sm-Nd同位素系统对土耳其西南部Menderes地块南部的含石榴石岩石进行地质年代学研究。研究区由土耳其西部泛非基底的岩石组成，这些岩石被阿尔卑斯变质事件覆盖。时间还没有得到充分的限制，特别是石榴石到目前为止还没有进行地质年代学研究。研究区岩石样品中含有石榴石晶体，大小从毫米到几厘米不等。直径达5厘米的大型自面体石榴石晶体将用于微采样方法，以限制石榴石生长的开始和持续时间。初步结果表明，石榴石岩心的Lu-Hf年龄为60 Ma，边缘年龄为~20 Ma。所选大型石榴石晶体的岩心和边缘剖面的显微采样和Lu-Hf + Sm-Nd年代学是本研究的主要课题。这些年龄将有助于限制门德雷斯地块复杂的变质历史。

This study will investigate garnet bearing rocks from the southern Menderes massif in southwest Turkey utilizing the Lu-Hf and Sm-Nd isotope systems for geochronology. The study area comprises rocks of the Pan-African basement of west Turkey which have been overprinted by an Alpine metamorphic event. The timing is yet only inadequately constrained, and especially garnets have not been subject to geochronological work so far. Rock samples of the study area contain garnet crystals with sizes ranging from millimeter to several centimeters. Large, euhedral garnet crystals up to 5cm in diameter will be used for a micro-sampling approach to constrain beginning and duration of the garnet growth. Preliminary results reveal Lu-Hf ages of a garnet core of 60 Ma and a ~20 Ma younger rim. Micro-sampling and Lu-Hf + Sm-Nd geochronology of core and rim sections of selected large garnet crystals is the main topic of this study. These ages will help to constrain the complex metamorphic history of the Menderes Massif.