Section 5.3 Notes
Mountain Formation Book pages 88-93
Name, Date, Period:________________________________
1. The first thing to do is sort out the differences among the terms mountain range, mountain
system, and mountain belts.
A. Let’s use an analogy to distinguish among these terms. Here’s the analogy:
An LP vinyl record.
It has two sides.
Each side has a songs list.
Each song has lyrics.
With the above scenario, aspects of the record appear next as a smaller part of the whole record.
B. Let’s do this with the 5.3 terms now.
The earth.
It has two mountain belts. (Eurasian-Melasian belt & Circum-Pacific belt, see pic p.88)
Each mountain belt consists of mountain systems. (-a group of adjacent mountain ranges)
Each mountain system consists of most of the world’s great mountain ranges. (- a group of
adjacent mountains with the same general shape and structure)
2. The Connection between Plate Tectonics & Mountains
A. Most mountains are formed where plates are colliding. After all, both of the mountain belts are
located along convergent plate boundaries.
B. Presently, there are some exceptions that are not located at convergent zones, but evidence
indicates they had formed at a collision boundary in the past (ex: Appalachians)
C. Three types of plate collisions form mountains.
a. Continental crust colliding with oceanic crust
-
This collision produces large-scale deformation that creates high mountains
Volcanic activity in the subduction zone contributes volcanic activity as well
You may also see scrapings of oceanic crust onto continental crust (terranes)
Example: the Cascade Mountains in the Pacific Northwest
b. Oceanic crust colliding with oceanic crust
-
This collision produces volcanic activity in the subduction zone that creates
volcanic mountains on the ocean floor
Example: the Mariana Islands in the North Pacific Ocean
c. Continental crust colliding with continental crust
-
This collision produces intense deformation of both continents
Example: the Himalaya Mountains
3. There are 4 types of mountains. Scientists classify them according to the way the crust was
deformed and shaped.
A. Folded Mountains and Plateaus
 Highest mountain ranges
 Result of continent-to-continent collision
 Exhibit complex folding (thus produce complex mountains like the Alps, Himalayas,
Appalachians, Ural Mountains, and Rockies)
 Exhibit severe uplifting (to create plateaus)
 Plateaus are large areas of flat-topped rocks that were pushed up gently enough to keep
the layers horizontal
 Most plateaus are found next to mountain ranges (examples: Tibetan Plateau is next to
the Himalayas and the Colorado Plateau is next to the Rockies.)
B. Fault-block Mountains and Grabens
 Huge blocks of the crust get sectioned off & shifted/tilted/uplifted by movements of the
surrounding crust
 Examples include the Sierra Nevada range of California, and the American southwest
desert region is broken up by fault-block mountains
 Sometimes a narrow block will section off and slip downward, creating a long narrow
valley called a graben; example is Death Valley in California
C. Volcanic Mountains
 Mountains that form when molten rock erupts onto earth’s surface
 Can erupt on land (example is the Cascade Range of Washington, Northern California,
and Oregon)
 Can erupt on ocean floor (example is at the mid-ocean ridges)
 Others, such as the Hawaiian Islands, form on the ocean floor over hot spots, pockets of
magma beneath the surface
D. Dome Mountains
 Molten rock rises beneath the crust but does not erupt
 It eventually cools underground & forms a dome of hardened rock that has the effect of
pushing up the rock layers above it
 It ends up looking like a circular dome
 Examples include the Black Hills of South Dakota and the Adirondack Mountains of New
York State