Flat Slab Subduction Mechanics: The Farallon Plate and the Laramide Orogeny

Geodynamic modeling of the Laramide orogeny and the western United States supports the theory that uplift of the region was subjected to the Farallon Plate flat slab subduction off the western continental margin during the Early Tertiary Period. Seismic and tomographic evidence was used in support of this concept. This book attempts to assemble some of the work completed to support this hypothesis along with the conceptual argument for slab disintegration and breakup during slab rollback of the Farallon Plate.Chapter 1 defines flat slab subduction theory, and the mechanisms and consequences of flat slab subduction. Chapter 2 summarizes North American dynamics and western United States tectonics before investigation into Farallon Plate subduction and migration beneath the western US. Chapter 3 considers subduction zone age and size constraints on flat slab subduction focusing on geodynamic model results. Chapter 4 presents Laramide age hydration of the lithosphere based on seismic investigation. Chapter 5 continues the seismic imaging discussion on flat slab subduction. Chapter 6 discusses flat slab subduction perturbations in the western US. Chapter 7 considers flat slab subduction relationships between magmatism and deformation. Chapter 8 tests the flat slab subduction theory pertaining to the Laramide uplift. Chapter 9 presents the kinematic history of the Laramide Orogeny. Chapter 10 presents historical magmatism, trench rollback, and slab breakup theory. Chapter 11 closes the book with slab disintegration and breakup of the Farallon Plate.