Lesson #12 Mountain Building

Objective: Explain the tectonic processes involved in mountain

building

Bell Ringer: Get a text book and define orogeny under the vocabulary section in

your science notebook

• Orogeny: The formation of mountain ranges by intense upward displacement of the earth's crust.

Convergent Boundaries

Converging plates create the world's largest mountain ranges. Each combination of plate types creates mountains: • continent-continent • continent-ocean • ocean-ocean

Continent - Continent• Two converging

continental plates smash upwards to create gigantic mountain ranges

• Stresses from this uplift cause folds and thrust faults, which allow the crust to rise upwards.

The crumpling of the Indian and Eurasian plates of continental crust

creates the Himalayas.

• Himalayas: Tallest Mountains on Earth.

• Himalayas: Tallest Mountains on Earth.

● Continental Convergence: (Mountain Building).

Copyright © 2010 Ryan P. Murphy

Water and Carbon

• The Swiss Alps -The African Plate is colliding with the Eurasian plate/

A f r i c a n P l a t e

E u r a s i a n P l a t e

• Mt. Everest (29,000 feet or 8,839 meters) – and growing.

Marine fossils found at the top of the world

Continent - Ocean• Subduction of oceanic lithosphere at

convergent plate boundaries also builds mountain ranges.

Water and Carbon

Examples of Mountains from Continent – Ocean?

Mt. St. Helens

Mt. Hood

Mt. Rainier

Ocean - Ocean

• A subduction zone where an oceanic plate subducts beneath another oceanic plate

• Creates an island arc

• Aleutian Islands Alaska Cleveland Volcano

● Continent Divergence (Moving apart).

Copyright © 2010 Ryan P. Murphy

Rift: A crack, split, or break in something.

Continental Divergent

• When tensional stresses pull crust apart, it breaks into blocks that slide up and drop down along normal faults.

• The result is alternating mountains and valleys, known as a basin-and-range

Example of Basin and Range??

Home sweet home!! Sierra Nevada Mountain Range