Abstract Fault inversion may lead to significant obliteration of earlier tectonic structures, thus preventing the straightforward interpretation of the complete kinematics and deformation history of faults. We adopt a multidisciplinary approach to: (1) reconstruct the tectonic evolution through space and in time of the extensionally-inverted Mt. Tancia Thrust (Central Apennines, Italy); (2) understand the deformation mechanisms and the transition and reactivation of compressional structures during negative tectonic inversion; and (3) constrain the origin of fluids involved during tectonic processes. To this end, we combined: (1) detailed geological mapping and multiscale structural analysis; (2) illite-smectite paleothermal indicators; (3) C, O, and clumped isotopes on calcite mineralizations and (4) K–Ar dating of authigenic and/or syn-kinematic illite from the Mt. Tancia Thrust fault rocks. We show that shortening occurred between ~9 and ~7 Ma, during possibly multiple events of fluid overpressure and shear rupturing involving fluids entrapped over long term within the host rocks. Post-compressive tectonic inversion occurred at ~3 Ma under fluid pressure fluctuations during shear events with an input of meteoric-derived fluids. Tectonic inversion is spatially confined within the first few metres below the thrust surface in a volume dominated by the partial overprinting, folding, transposition, and re-utilization of the earlier compressional fabric.

中文翻译：

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伸展倒转推力的结构和演化（Mt. Tancia Thrust，中央亚平宁山脉）：地质、结构、地球化学和 K-Ar 年代学约束

摘要 断层反转可能导致早期构造构造的显着消失，从而阻碍对断层完整运动学和变形历史的直接解释。我们采用多学科方法：（1）重建伸展倒转的 Mt. 的时空构造演化。Tancia Thrust（意大利中部亚平宁山脉）；(2) 了解负构造反转过程中的变形机制和挤压构造的转变与再活化；(3) 限制构造过程中涉及的流体的来源。为此，我们结合了：（1）详细的地质填图和多尺度结构分析；(2)伊利石-蒙脱石古热指标；(3) C、O、和方解石矿化上的团块同位素和 (4) 来自 Mt. 山的自生和/或同运动伊利石的 K-Ar 年代测定。Tancia 逆冲断层岩。我们表明，缩短发生在~9 到~7 Ma 之间，可能发生在流体超压和剪切破裂的多次事件中，涉及流体长期滞留在主岩中。压缩后构造反转发生在~3 Ma 在剪切事件期间流体压力波动下，输入大气衍生流体。构造反转在空间上被限制在逆冲面下方的最初几米内，其体积主要由早期压缩织物的部分叠印、折叠、换位和再利用所主导。在可能发生多次流体超压和剪切破裂事件期间，涉及流体长期滞留在主岩中。压缩后构造反转发生在~3 Ma 在剪切事件期间流体压力波动下，输入大气衍生流体。构造反转在空间上被限制在逆冲面下方的最初几米内，其体积主要由早期压缩织物的部分叠印、折叠、换位和再利用所主导。在可能发生多次流体超压和剪切破裂事件期间，涉及流体长期滞留在主岩中。压缩后构造反转发生在~3 Ma 在剪切事件期间流体压力波动下，输入大气衍生流体。构造反转在空间上被限制在逆冲面以下的最初几米内，其体积主要是早期压缩织物的部分叠印、折叠、换位和再利用。