Oceanic plate subduction can exert extensional, compressional or both types of deformations simultaneously in overriding plates. In this study, we explore the factors controlling these two competing modes of deformation in response to contrasting stress fields. Two-dimensional computational fluid dynamics models are presented to show that the dip and age of subducting slabs are crucial parameters to modulate the extensional versus compressional deformations. Shallow-dipping (< 30°) and/or young (< 60 Myr) subducting slabs favor compressional tectonics to form an orogenic wedge (accretionary type), whereas steeply dipping (> 45°) and/or old (> 60 Myr) slabs facilitate extensional tectonics, expressed as a back-arc basin (non-accretionary type). We validate the parametric analysis by comparing our model results with the observed modes of overriding plate deformation in natural subduction zones.

大洋板块俯冲可以在上覆板块同时施加伸展，压缩或两种变形。在这项研究中，我们探索了控制这两种竞争模式以响应相反的应力场的因素。提出了二维计算流体动力学模型，以表明俯冲板的倾角和年龄是调制拉伸变形与压缩变形的关键参数。浅倾（<30°）和/或年轻（<60 Myr）俯冲板块有利于构造构造以形成造山楔（增生型），而陡倾（> 45°）和/或旧板块（> 60 Myr）有利于伸展构造，表示为弧后盆地（非增生类型）。通过将我们的模型结果与自然俯冲带中覆盖板变形的观测模式进行比较，我们验证了参数分析。