The Iceland Plate Boundary Zone: Propagating Rifts, Migrating Transforms, and Rift‐Parallel Strike‐Slip Faults

Abstract Unlike most of the Mid‐Atlantic Ridge, the North America/Eurasia plate boundary in Iceland lies above sea level where magmatic and tectonic processes can be directly investigated in subaerial exposures. Accordingly, geologic processes in Iceland have long been recognized as possible analogs for seafloor spreading in the submerged parts of the mid‐ocean ridge system. Combining existing and new data from across Iceland provides an integrated view of this active, mostly subaerial plate boundary. The broad Iceland plate boundary zone includes segmented rift zones linked by transform fault zones. Rift propagation and transform fault migration away from the Iceland hotspot rearrange the plate boundary configuration resulting in widespread deformation of older crust and reactivation of spreading‐related structures. Rift propagation results in block rotations that are accommodated by widespread, rift‐parallel, strike‐slip faulting. The geometry and kinematics of faulting in Iceland may have implications for spreading processes elsewhere on the mid‐ocean ridge system where rift propagation and transform migration occur.