Presentation on theme: "Physical Geology Chapter 11 Part 2 – Mountain Building."— Presentation transcript:
Physical Geology Chapter 11 Part 2 – Mountain Building
Definition A mountain is the most extreme type of deformation Relatively small “wrinkles” in the earth’s crust may soar from 1 to 8 km above sea level A mountain is a piece of land that is higher than a hill and stands much higher than the land around it. Mountains have steep sides and a pointed or rounded top. The top of a mountain is very cold. Mountains are created over long periods of time by tremendous forces of the earth.
Range – a group of adjacent mountains related by shape and structure
System – a group of adjacent ranges
Belts – the two major mountainous regions of the world; Eurasian- Melanesian & Circum-Pacific belts
How do mountains form? It’s all plate tectonics!
Types of Mountains Folded and Plateaus Faulted Domes Volcanic Blossom Peak, Post Falls, Idaho
Folded Mountains Compression stress squeezes up accordion-like folds May also result in formation of uplifted, broad, flat plateaus Himalayas, Rockies, Appalachians, Urals, parts of the Alps
Types of Folds
Faulted Mountains Vertical movement at fracture zones Tilted blocks, lift or drop at single faults Uplift at double faults Sierra Nevada, Tien Shan, western foothills of the Rockies (Basin/Range region)
Typical Fault Block Mountains
Fault block valley Fault block ridge
Basin and Range
Domes and Basins Gentle upwarping or downwarping of crustal rock produce domes and basins Erosion of these structures results in an outcrop pattern that is roughly circular or elongated Black Hills, Adirondacks, Stone Mountain
Volcanic Mountains Eruptions of gases, magma, cinder/ash and pulverized surface material Piles of expelled material form cones that may stand out from surrounding terrain as mountains –Shield cones –Cinder cones –Composite cones