Late Quaternary slip rates on the Acireale-Piedimonte normal faults and tectonic origin of Mt. Etna (Sicily)
Late Quaternary slip rates on the Acireale-Piedimonte normal faults and tectonic origin of Mt. Etna (Sicily)
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阿奇雷亚莱-皮埃迪蒙特正断层的晚第四纪滑动速率和埃特纳火山（西西里岛）的构造起源
DOI：
10.1016/s0012-821x(97)00005-8
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发表时间：
1997
影响因子：
5.3
通讯作者：
P. Gillot
中科院分区：
文献类型：
--
作者：
C. Monaco;P. Tapponnier;L. Tortorici;P. Gillot
山埃特纳位于沿着西西里的东海岸，靠近海布尔高原的大陆地壳和爱奥尼亚盆地的中生代洋壳之间的边界。主要活动断裂为近天山断裂带。埃特纳切割其东侧的底部，形成一个30公里长的NNE和NNW向ene 'chelon断层段系统（Acireale-Piedimonte系统），表现出倾滑和倾斜（右侧）运动。大多数区段与浅深度地震活动有关，并且都具有晚更新世至全新世的垂直滑动速率，范围在1至2毫米/年之间，是全球主要活动正断层的典型。喷发裂缝，安排在北北东向东北走向的地区，削减了火山的最高斜坡，在下盘的正常断层系统。构造分析表明，目前的运动沿着活动断层和喷发裂缝是运动学上兼容的，简单地与正在进行的，WNW-ESE方向的区域扩展。这种伸展在更大的范围内表现为意大利南部的活动构造，在那里，所有大的、浅的、历史上的地震都被限制在从北方卡拉布里亚弧延伸到西西里东南部的狭窄的正断层带或裂谷带内。卡拉布里亚（阿斯普罗蒙特）裂谷带最南端的西倾断层横穿卡拉布罗-佩洛里坦冲断带，与大部分东倾的阿西雷-皮耶迪蒙特断层汇合，沿着爱奥尼亚海洋岩石圈的西部边界，继续向南延伸为马耳他悬崖。因此，我们将埃特纳的岩浆活动与弯曲处一个向东的地壳规模正断层下盘的扩张应变联系起来，在这个弯曲处，当西西里-卡拉布里亚裂谷带开始穿越卡拉布里亚弧时，它向东转向60°，离开了爱奥尼亚海的东向边缘，赶上了更北的第勒尼安海的西向边缘。
Mt. Etna is located along the east coast of Sicily, near the boundary between the continental crust of the Hyblean Plateau and the Mesozoic oceanic crust of the Ionian basin. The main active faults near Mt. Etna cut the base of its eastern flank, forming a 30 km long system of NNE- and NNW-trending, ene´chelon fault segments (the Acireale-Piedimonte system), showing dip-slip and oblique (right-lateral) motion. Most segments are associated with shallow-depth seismicity and all have Late Pleistocene to Holocene vertical slip rates ranging between 1 and 2 mm/yr, typical of major active normal faults worldwide. Eruptive fissures, arranged in NNE- to NE-trending zones, cut the highest slopes of the volcano, on the footwall of the normal fault system. Structural analysis suggests that current motions along both the active faults and eruptive fissures are kinematically compatible and simply linked with ongoing, WNW-ESE-directed regional extension. Such extension characterizes, at a greater scale, the active tectonics of southern Italy, where all large, shallow, historical earthquakes have remained confined within a narrow normal fault belt or rift zone stretching from the northern Calabrian Arc to southeastern Sicily. The southernmost, west-dipping, faults of that rift zone in Calabria (Aspromonte) cut across the Calabro-Peloritan thrust belt to join the mostly east-dipping, Acireale-Piedimonte faults, along the western boundary of Ionian oceanic lithosphere, which continues southwards as the Malta escarpment. We thus relate magmatism at Etna to dilational strain on the footwall of an east-facing, crustal-scale normal fault at the bend where the Siculo-Calabrian rift zone veers ≈ 60° eastwards as it begins to cross the Calabrian Arc, leaving the east-facing margin of the Ionian Sea, to catch up with the west-facing margin of the Tyrrhenian Sea farther north.