In this review paper, we compile observations that have been made over decades of research on the Cascadia convergent boundary and re-examine the deformation using structural kinematic models, thereby providing new insights. Deformation in the subducting Juan de Fuca slab and the overriding North American plate is primarily accommodated by fracturing. We show that the along-strike deformation patterns are a function of fracture density and activity, which influences coupling with the overriding North American plate and the underlying mantle wedge. We analyze the deformation within a fracture kinematics framework and show that the orientations of the fractures and motion history follow expected empirical fracture mechanics models and are used to provide a more detailed kinematic history of the Cascadia convergent boundary. We focus on the Gorda plate of the Juan de Fuca subducting slab and show that it is intensely fractured with curved magnetic anomalies such that the brittle deformation is collectively expressed macroscopically as a deforming continuum. The Gorda plate has changed shape via NS shortening and clockwise rotation without losing cohesion at the plate-scale, which suggests that the fractures form an interlocking network to accommodate ductile deformation via cataclastic flow. In the forearc, the fracture and velocity patterns suggest that deformation is accommodated by a continental-scale right-lateral shear zone, trending 320°/140° and is assisted via crustal-scale cataclastic flow. We suggest that ETS activity is strongly correlated to deformation in the over-riding plate. The Gorda plate is also used to better understand larger-scale plate dynamics. We demonstrate that the Gorda plate acts as a ductile deformation zone to assist global plate mobility. Additionally, details of the magnetic lineation patterns in the Gorda plate indicate that slab pull overtakes plate rotation post-subduction. This suggests that plate behavior is strongly influenced by its internal deformation and coupling with the mantle post-subduction.

在这篇综述论文中，我们汇总了几十年来对卡斯卡迪亚收敛边界的研究结果，并使用结构运动学模型重新检查了变形，从而提供了新的见解。俯冲的 Juan de Fuca 板片和压倒性的北美板块的变形主要通过压裂来调节。我们表明，沿走向的变形模式是裂缝密度和活动的函数，这会影响与上覆北美板块和下伏地幔楔的耦合。我们分析了断裂运动学框架内的变形，并表明断裂的方向和运动历史遵循预期的经验断裂力学模型，并用于提供 Cascadia 收敛边界的更详细的运动学历史。我们专注于 Juan de Fuca 俯冲板片的 Gorda 板块，并表明它与弯曲的磁异常发生强烈断裂，因此脆性变形在宏观上被集体表示为变形连续体。Gorda 板块通过 NS 缩短和顺时针旋转改变了形状，而在板块尺度上没有失去凝聚力，这表明裂缝形成了一个联锁网络，以适应碎裂流的延性变形。在弧前，断裂和速度模式表明变形由大陆尺度的右侧剪切带调节，趋势为 320°/140°，并通过地壳尺度的碎裂流辅助。我们认为 ETS 活动与覆盖板的变形密切相关。Gorda 板块也用于更好地理解更大规模的板块动力学。我们证明了 Gorda 板块充当延性变形区以帮助全球板块移动。此外，Gorda 板块中磁线模式的细节表明，板块拉力超过了俯冲后的板块旋转。这表明板块行为受到其内部变形和与地幔后俯冲耦合的强烈影响。