High‐pressure metasediments in central Turkey: Constraints on the Neotethyan closure history
High‐pressure metasediments in central Turkey: Constraints on the Neotethyan closure history
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DOI：
10.1029/2009tc002650
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发表时间：
2010-10
期刊：
影响因子：
4.2
通讯作者：
A. Pourteau;O. Candan;R. Oberhänsli
中科院分区：
文献类型：
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作者：
A. Pourteau;O. Candan;R. Oberhänsli
中安纳托利亚的海洋域和大陆块体的分布仍然是理解特提斯地区阿尔卑斯山地球动力学演化的一个挑战。在中新生代边界的Neotethys海洋分支的消耗将土耳其中部的中央安纳托利亚结晶杂岩和土耳其西部的Anatolide-Tauride地块与欧亚大陆北缘连接在一起。这两个区域是否构成了一个或两个不同的大陆块，仍然是一个有争议的问题。在阿费扬带局部发现了高压变质作用，但被定义为Anatolide-Tauride地块的绿片岩相变质带。由于Afyon带构成了相当于暴露在伊兹密尔-安卡拉缝合带南端的大陆边缘的变质作用，这促使我们重新评估其变质演化，以更好地了解土耳其西部和中部的关系。我们的研究表明，高压矿物铁镁碳磷石和蓝闪石存在于整个Afyon带中，我们重新认为该带为蓝片岩相带。此外，我们还提出了一种构造重建，剥离了碰撞后构造。它揭示了今天高压带的弯曲与始新世Anatolide-Tauride地块围绕中安纳托利亚结晶杂岩南缘的碰撞一致。我们认为，中央安纳托利亚结晶杂岩和安纳托利德-陶里德地块是被新特提斯洋带分隔的两个不同的陆块，后者的闭合产生了与俯冲有关的变质作用，前者在晚白垩世至早新生代产生了弧火山作用和高级变质作用。
The distribution of oceanic domains and continental blocks in Central Anatolia remains a challenge in understanding the Alpine geodynamic evolution of the Tethys realm. The consumption of a Neotethys oceanic branch at the Mesozoic‐Cenozoic boundary welded the Central Anatolian Crystalline Complex in central Turkey and the Anatolide‐Tauride Block in western Turkey, with the northerly Eurasian margin. Whether those two regions constituted a single or two distinct continental masses is still matter of debate. High‐pressure metamorphism has been locally evidenced in the Afyon Zone, which was, however, defined as a greenschist‐facies metamorphic zone of the Anatolide‐Tauride Block. Since the Afyon Zone composes a metamorphic equivalent of a continental margin exposed far south of the Izmir‐Ankara suture zone, this encouraged us to reevaluate its metamorphic evolution in order to better understand the relation between western and central Turkey. Our investigations reveal that the high‐pressure minerals Fe‐Mg‐carpholite and glaucophane are present in the entire Afyon Zone, which we reconsider as a blueschist‐facies zone. We additionally present a tectonic reconstruction, stripping off the postcollisional tectonics. It reveals that today's bending of the high‐pressure belt is consistent with an Eocene collision of the Anatolide‐Tauride Block around the southern edge of the Central Anatolian Crystalline Complex. We argue that the Central Anatolian Crystalline Complex and the Anatolide‐Tauride Block were two distinct continental masses separated by a Neotethyan oceanic stripe, the closure of which engendered subduction‐related metamorphism in the latter and arc volcanism and high‐grade metamorphism in the former by late Cretaceous to early Cenozoic.