The origin of changes in structural style across the Bandar Abbas syntaxis, SE Zagros (Iran)
The origin of changes in structural style across the Bandar Abbas syntaxis, SE Zagros (Iran)
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扎格罗斯东南部阿巴斯港结构风格变化的起源（伊朗）
DOI：
10.1016/j.marpetgeo.2004.04.001
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发表时间：
2004
影响因子：
4.2
通讯作者：
D. D. de Lamotte
中科院分区：
文献类型：
--
作者：
M. Molinaro;J. Guézou;P. Leturmy;S. A. Eshraghi;D. D. de Lamotte
班达尔阿巴斯构造结标志着扎格罗斯碰撞带和马克兰俯冲相关棱柱体之间的过渡，构成了阿尔卑斯-喜马拉雅山脉带内的主要构造特征。在扎格罗斯的前陆部分（扎格罗斯褶皱冲断带，ZFTB），过渡的特点是结构趋势和风格的突然变化，以及地震活动和盐底辟作用从西向东的构造结的快速减少。滑脱深度和岩性影响构造结两侧褶皱的几何形状和大小，而沿着基底滑脱的不同力学耦合影响内部岩石变形的程度。因此，结合结西侧的短而宽的褶皱沿着8公里深的霍尔木兹陨石分离，在表面可见许多盐底辟。该区强震活动表明基底参与了变形。与此相反，长而窄的褶皱东侧的结似乎是由摩擦滑动沿着6公里深的拆离控制。没有地震活动表明，基底没有参与该地区的变形。我们认为，这些结构的基底滑脱对应于NNE-SSW走向阿曼中生代推覆体的侵蚀顶部，该推覆体是由阿拉伯边缘上的特提斯的晚白垩世仰冲造成的。这些结构在阿曼半岛北方的陆地上可见，在霍尔木兹海峡下面继续向北的海上地震剖面中也可见。最后，地图视图的观察表明，主要的扎格罗斯冲断层和Zendan故障分离ZFTB的内部区域的造山带是浅的低角度逆冲断层，而不是陡峭的倾斜故障。
The Bandar Abbas syntaxis marks the transition between the Zagros collisional belt and the Makran subduction-related prism and constitutes a major structural feature within the Alpine–Himalayan mountain belt. Within the foreland part of the Zagros (the Zagros Fold Thrust Belt, ZFTB), the transition is marked by a sudden change in structural trends and style and a rapid decrease in seismicity and salt diapirism from west to east of the syntaxis. The depth to decollement and lithology affect the geometry and size of the folds on each side of the syntaxis, while different mechanical coupling along the basal decollement affects the degree of internal rock deformation. Thus the short and broad folds of the western side of the syntaxis are decoupled along the 8-km deep Hormuz evaporites, visible at surface in numerous salt diapirs. Strong seismicity in this area suggests that the basement is involved in the deformation. By contrast, the long and narrow folds of the eastern side of the syntaxis appear to be controlled by frictional slip along a 6-km deep detachment. The absence of seismicity suggests that the basement is not involved in the deformation in this area. We propose that the basal decollement for these structures corresponds to the eroded top of the NNE–SSW trending Oman Mesozoic nappes resulting from Late Cretaceous obduction of Tethys on the Arabian margin. These structures are visible onshore in the northern tip of the Oman peninsula and seen in offshore seismic profiles continuing northward beneath the Strait of Hormuz. Finally, map view observations show that the Main Zagros Thrust and the Zendan Fault—separating the ZFTB from the internal zones of the orogen—are shallow low angle thrust faults rather than steeply dipping faults.