Contrasting styles of fault reactivation in curved orogenic belts: Examples from the Central Apennines (Italy)
Contrasting styles of fault reactivation in curved orogenic belts: Examples from the Central Apennines (Italy)
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弯曲造山带断层再活动的对比风格：来自亚平宁山脉中部（意大利）的例子
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
P. Pace
中科院分区：
文献类型：
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作者：
F. Calamita;S. Satolli;V. Scisciani;P. Esestime;P. Pace
亚平宁褶皱冲断带的几何形状受到阿德里亚古边缘原始构造的强烈影响。在亚平宁中部，前冲断正断层(前造山二叠/三叠纪-侏罗纪和同造山新近纪)在新近纪-第四纪造山过程中被挤压运动学重新激活。我们研究了亚平宁中部已有伸展断裂对逆冲构造的控制作用。通过结合地表地质资料和地震线解释，我们描述了来自亚平宁中部的一些突出的褶皱冲断构造(Setteporte、Sabini山脉、Sibillini山脉、Montag na dei Fiori、Gran Sasso山脉、Maiella山和Casoli-Bomba)的正反演几何图形。在这些构造中，不同类型的断层再活动取决于它们相对于随后挤压的NE-SW向应力场的方向。背斜后肢NW-SE和WNW-ESE向的前冲断正断层在逆冲面的上盘块体中发生位移和被动平移，呈现经典的捷径几何学(捷径背斜)。与之不同的是，北S向背斜中的造山前正断层是在逆冲变形背景下重新激活的，主要表现为沿逆冲断层的倾滑运动学和沿背冲断层的走滑运动学(重新激活背斜)。这些案例记录了褶皱冲断构造中与先前存在的伸展断裂走向有关的几何差异，表明与同一反转事件有关的不同重新激活几何图形可以在弯曲的褶皱冲断带中在区域范围内共存。所提出的反转构造模型和由此产生的褶皱冲断带几何学可能适用于类似的造山带。
The geometry of the Apennine fold-and-thrust belt has been strongly influenced by the original architecture of the Adria paleomargin. In the Central Apennines, pre-thrusting normal faults (pre-orogenic Permian(?)/Triassic–Jurassic and synorogenic Neogene) were reactivated with compressional kinematics during the Neogene–Quaternary orogenesis. We present a study of the control of preexisting extensional faults on thrust tectonics in the Central Apennines. We describe positive inversion geometries of some salient fold-and-thrust structures from the Central Apennines (Setteporte, the Sabini Mountains, the Sibillini Mountains, Montagna dei Fiori, the Gran Sasso range, Maiella Mountain, and Casoli-Bomba) by integrating surface geological data and seismic-line interpretation. In these structures, different styles of fault reactivation depend on their orientation with respect to the subsequent compressional NE-SW-trending stress field. The NW-SE– and WNW-ESE–trending pre-thrusting normal faults in the backlimbs of the anticlines were displaced and passively translated in the hanging-wall blocks of the thrust planes, thus exhibiting a classical shortcut geometry (shortcut anticlines). Differently, pre-orogenic normal faults in the N-S–trending anticlines were reactivated in a transpressive deformational context, as documented by the mainly dip-slip and strike-slip kinematics along the thrusts and back thrusts, respectively (reactivation anticlines). The cases studied document differences in geometry in fold-and-thrust structures related to the trend of preexisting extensional faults, showing that different reactivation geometries linked to the same inversion event can coexist at regional scale in curved fold-and-thrust belts. The proposed inversion tectonic model and the resulting geometry of the fold-and-thrust belt could possibly be applied to analogous orogenic belts.