The different movements and interactions of the lithosphere plates result in many different mountain landforms. Mountains can be classified into five different types, based on what they look like and how they were formed. These are fold, fault-block, dome, plateau and volcanic mountains. (Volcanic mountains are discussed in lesson 14.9.) 14.3.1 Fold mountains The most common type of mountain, and the world’s largest mountain ranges, are fold mountains. The process of folding occurs when two continental plates collide, and rocks in the Earth’s crust buckle, fold and lift up. The upturned folds are called anticlines, and the downturned folds are synclines (see FIGURE2 ). These mountains usually have pointed peaks.
FIGURE2 The formation of fold mountains
Thrust fault
Anticline valley
Anticline valley
Syncline ridge
Syncline ridge
Anticline
Syncline
Anticline
Syncline
Anticline
Examples of fold mountains include: • Himalayas in Asia • Alps in Europe • Andes in South America • Rocky Mountains in North America • Urals in Russia.
SkillBuilder discussion Geographical inquiry 1. Explain to a partner why fold mountains form. 2. What is the difference between an anticline and a syncline? 3. In FIGURE2 , where is the plate boundary?
FIGURE3 The pointed peaks of the Ural Mountains in Russia
TOPIC14 Geomorphological processes and hazards
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