Chapter 20.2 and 20.3

1. Chapter 20.2 and 20.3 Orogeny and Other Types of Mountain Building

2. orogeny and compressive forces • Orogeny: All Processes that form mountain ranges • Compressive forces: processes that squeeze the crust and cause intense deformation in the form of folding, faulting and metamorphism

3. Convergence • Oceanic-oceanic convergence: one plate is subducted and the other has magma forced upward which forms an island arc • Oceanic-continental convergence: oceanic plate descends and the continental plate is forced upward forming a mountain belt • Continental-continental convergence: both continental crusts become highly folded; the magma that results solidifies beneath the Earth’s surface; continental crust cannot subduct into the mantle because of its low density

7. Guess which type of mountain is the tallest? #1: continental-continental convergence #2: oceanic-continental convergence #3: oceanic-oceanic convergence

8. 20.3 Other Types of Mountains • Divergent-Boundary Mountains: Underneath the ocean’s floor, volcanic mountains form a continuous chain that snakes along the Earth’s ocean floor

10. Uplifted Mountains • When a region of the Earth is forced upward as a unit • The reasons for large scale uplift are not well known • A plateau may form when a region as a whole is uplifted • The Sierra Nevadas and the Adirondack Mountains are both examples of uplifted mountains

11. Fault-Block Mountain • Land movement at a fault lifts land on one side of the fault and drops it on the other