Tension gash‐like back‐arc basin opening and its control on subduction rollback inferred from Tertiary faulting in Sardinia
Tension gash‐like back‐arc basin opening and its control on subduction rollback inferred from Tertiary faulting in Sardinia
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DOI：
10.1029/2005tc001904
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发表时间：
2006-08
期刊：
影响因子：
4.2
通讯作者：
Heiko Helbing;W. Frisch;P. Bons;J. Kuhlemann
中科院分区：
文献类型：
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作者：
Heiko Helbing;W. Frisch;P. Bons;J. Kuhlemann
东北撒丁岛古生代基底的第三纪活化反映了与西地中海俯冲回退有关的张拉弧后构造。在阿尔格萨奇-普罗旺-帕拉尔盆地张开期间，撒丁岛中部的主导构造——左旋Nuoro断裂在撒丁岛西部裂谷和北部蒂勒尼安盆地之间起径向转移作用。随后，作为撒丁岛东南部右侧断裂集的共轭断层，它形成了南部第勒尼安盆地的张拉式裂口。由此产生的相对于弧的反向旋转由基底中重新定向的岩脉显示。南部第勒尼安盆地的张力裂缝状开口决定了撒丁岛东部边缘的海湾形状和卡拉布里亚边缘的弧形形状。这种对南部第勒尼安盆地回滚的构造控制表明，弧后盆地的张拉式裂口是俯冲回滚的内在特征。
The Tertiary reactivation of the Paleozoic basement in NE Sardinia is shown to reflect transtensional back‐arc tectonics, related to the western Mediterranean subduction rollback. During the Algéro‐Provençal basin opening, the left‐lateral Nuoro Fault, which is the prevailing structure in central Sardinia, operated as radial transfer between the west Sardinian rift and northern Tyrrhenian basin. Subsequently, it contributed to a tension gash‐like opening of the southern Tyrrhenian basin as conjugate fault to a right‐lateral fault set in SE Sardinia. Resulting antithetic rotations with respect to the arc are revealed by reoriented dikes in the basement. The tension gash‐like opening of the southern Tyrrhenian basin determined the gulf shape of the east Sardinian margin and the arc shape of its Calabrian counterpart. This structural control on the southern Tyrrhenian rollback scenario suggests that tension gash‐like opening of back‐arc basins represents an intrinsic aspect of subduction rollback.