Collaborative Research: Extensional Unroofing of the Central Menderes Metamorphic Complex, Southwestern Turkey

爱琴海地区从晚白垩世到始新世经历了一系列的大陆板块碰撞。该地区的后碰撞伸展，虽然在时间和性质上存在争议，但导致了几个变质带的折返。其中最大的一个是门德雷斯地块，容纳了显著的地壳伸展，这可能是由以下原因造成的：（1）构造逃逸和侧向挤压，其中安纳托利亚板块沿着北安纳托利亚断层和东安纳托利亚断层向西移动，（2）由于沿着希腊弧的俯冲而导致的弧后扩张/板片回滚，或（3）经历了古近纪收缩的热弱化岩石圈的造山塌陷。这些假设进行了测试，使用地质年代学，使门德雷斯地块在确定的基本板块构造过程，促进大陆岩石圈的扩展的一个关键地点。 研究的主要目标是描述Menderes地块中部岩石的岩石学演化特征，以确定爱琴海地区从挤压到伸展的构造过渡的原因。该项目涉及野外工作和地球化学数据采集，包括最近开发的原位离子微探针独居石年代学和氩-氩钾长石多扩散域建模技术。离子探针技术保存了颗粒和岩石结构，当与电子探针化学分析相结合时，可以清楚地解释年龄的含义。氩-氩多扩散域模型表明，一个单一的钾长石样品可以揭示冷却历史的一个广泛的部分，而不是一个单一的基准。这个项目是由一个美国团队合作的，包括伊丽莎白·卡特洛斯博士、易卜拉欣·塞曼博士（俄克拉荷马州州立大学地质学院）和马特·科恩博士（地质学系）。地质科学;南卡罗来纳州大学）和包括Cemal Goncuoglu博士（中东技术大学地质工程系，安卡拉）在内的土耳其小组。参与这项计划的两名研究生接触到不同的文化，紧张的野外工作和各种地球化学方法。

The Aegean region experienced a series of continental plate collisions from Late Cretaceous to Eocene time. Post-collisional extension in the region, although controversial in its timing and nature, caused the exhumation of several metamorphic belts. The largest of these, the Menderes Massif, accommodated significant crustal extension, which may have been caused by: (1) tectonic escape and lateral extrusion, in which the Anatolian plate moves westward along the North and East Anatolian Faults, (2) back-arc spreading/slab roll back due to the subduction along the Hellenic Arc, or (3) orogenic collapse of thermally weakened lithosphere that experienced Paleogene contraction. These hypotheses are tested using geochronology, making the Menderes Massif a key locale in identifying the fundamental plate tectonic processes that facilitate extension in the continental lithosphere. The main goal of the research is to characterize the petrologic evolution of rocks in the central Menderes Massif to identify the cause of tectonic transition from compression to extension in the Aegean Region. The project involves fieldwork and geochemical data acquisition, including recently developed techniques of in situ ion microprobe monazite geochronology and argon-argon K-feldspar multi-diffusion domain modeling. The ion microprobe technique preserves the grain and rock fabric, and, when combined with electron microprobe chemical analyses, allow for a clear interpretation of meaning of the age. The argon-argon multi-diffusion domain model shows that a single K-feldspar sample can reveal a broad segment of a cooling history, rather than a single datum. This project is collaborative between a U.S. team including Dr. Elizabeth Catlos, Dr. Ibrahim Cemen (School of Geology; Oklahoma State University) and Dr. Matt Kohn (Dept. Geological Sciences; University of South Carolina), and a Turkish team including Dr. Cemal Goncuoglu (Middle East Technical University, Department of Geological Engineering, Ankara). The two graduate students participating in this proposal are exposed to a different culture, intense fieldwork, and a variety of geochemical methods.