The lateral boundary of a metamorphic core complex: The?Moutsounas shear zone on Naxos, Cyclades, Greece

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• 作者：Shuyun Cao ; Franz Neubauer ; Manfred Bernroider ; Junlai Liu
• 关键词：Naxos metamorphic core complex ; Moutsounas shear zone ; Microstructure ; EBSD texture ; Paleopiezometry ; Chlorite geothermometry
• 刊名：Journal of Structural Geology
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：54
• 期：Complete
• 页码：103-128
• 全文大小：14025 K

文摘

We describe the structure, microstructures, texture and paleopiezometry of quartz-rich phyllites and marbles along N-trending Moutsounas shear zone at the eastern margin of the Naxos metamorphic core complex (MCC). Fabrics consistently indicate a top-to-the-NNE non-coaxial shear and formed during the main stage of updoming and exhumation between ca. 14 and 11?Ma of the Naxos MCC. The main stage of exhumation postdates the deposition of overlying Miocene sedimentary successions and predates the overlying Upper Miocene/Pliocene conglomerates. Detailed microstructural and textural analysis reveals that the movement along the Moutsounas shear zone is associated with a retrograde greenschist to subgreenschist facies overprint of the early higher-temperature rocks. Paleopiezometry on recrystallized quartz and calcite yields differential stresses of 20-77?MPa and a strain rate of 10^?15-10^?13?s^?1 at 350?¡ãC for quartz and ca. 300?¡ãC for calcite. Chlorite geothermometry of the shear zone yields two temperature regimes, 300-360?¡ãC, and 200-250?¡ãC. The lower temperature group is interpreted to result from late-stage hydrothermal overprint.