1. MOUNTAIN BUILDING

2. Deformation – refers of all changes in the original shape or size of a rock body.
Brittle deformation – at the earth’s surface, low temperatures and low pressures, solid rock fractures
Ductile deformation – deep with in the Earth, high temperatures and high pressures, rock is deformed without breaking
The mineral composition and texture also affects how it will deform.
Small stresses applied over time will cause the rock to bend.

3. Stress – force per unit area acting on a solid
Strain – the change in shape or volume
Tensional stress – causes a material to be stretched
Compressional stress – causes a material to shorten
Shear stress – causes a material to be distorted

5. Folds – during mountain building flat-lying sedimentary and igneous rock are bent into a series of ripples
Anticlines – arching of rock layers
Synclines – downfolds or troughs
Monoclines – large step-like folds

9. Faults – fractures in the crust along which movement has taken place
Normal fault – when the hanging wall block moves down relative to the footwall block, caused by tensional forces
Reverse fault – the hanging wall block moves up relative to the footwall, caused by compressional forces
Thrust faults – reverse faults with dips less than 45o
Strike-slip faults – the movement is horizontal and parallel, caused by shear stress, San Andreas fault
Joints – most common rock structure, fractures along which no appreciable movement has occurred

14. Mountains – classified by the dominant processes that deformed them
Folded Mountains – formed by folding, compressional stress is the major force that formed them; examples – Appalachians, Alps, northern Rocky Mountains

16. Fault-block Mountains – mountains that form as large blocks of crust are uplifted and tilted along normal faults; examples – Tetons Range, Sierra Nevadas

18. Horst and Grabens – formed from tensional forces, horsts are uplifted structures and grabens is where the blocks dropped down; example – the Basin and Range region of Nevada, California and Utah

19. Domes – formed by upwarping and exposing older igneous and metamorphic rock; example – Back Hills of South Dakota
Basins – downwarping structures having a circular shape

20. Mountain Building – Orogenesis
Mountain Building at Convergent Boundaries – colliding plates provide the compressional forces that deform rock
Oceanic-Oceanic Convergence – forms volcanic island arcs, Aleutian Islands of Alaska

22. Ocean- Continental Convergence – ocean crust subducts the continental crust, the continental crust is deformed, creates volcanic arcs on continent
Accretionary wedge – accumulation of different sedimentary and metamorphic rocks
Continent-Continent Convergence – form folded mountains; examples – Himalayas, Ural mountains

23. Mountain Building at Divergent Boundaries – fault-block mountains
Non-Boundary Mountains – Hawaiian Islands are volcanic islands formed by a hot spot
Continental Accretion – smaller crustal fragments collide and merge with continental margins; example – many of mountains rimming the Pacific Canada and Alaska
Terranes – any crustal fragment that has a geologic history distinct from adjoining terranes

24. Isostacy – a floating crust in gravitational balance
Isostacy – a floating crust in gravitational balance. As mountains erode, the crust rises in response to the reduced load. Erosion and uplift continue until the mountains reach normal crustal thickness
The weight of the ice sheet during the Pleistocene depressed the Earth’s crust hundreds of meters. Since the ice age, uplift has occurred