Fold Mountains

Discover how majestic fold mountains are formed by Earth's powerful plate movements!

Formation of the Continents Before you read the article, watch this video so you can easily relate how the folds are created. Fold MountainsFrom: NewsELA, adapted 3.28.19;By: National Geographic Society;Word Count 861;Level 730L Earth's hard outer layer is called the crust. It is made up of large slabs called tectonic plates. The plates fit together like puzzle pieces. Fold mountains are created where two or more plates are pushed together. At these boundaries, rocks are folded into hills and mountains.Fold mountains are created through a process called orogeny. It takes millions of years to create a fold mountain. However, you can easily see how it works. Cover a table with a tablecloth, or place a rug flat on the floor. Now push the edge of the tablecloth or rug. You will see wrinkles fold on top of each other.Most Famous Mountain Ranges Are Fold MountainsFold mountains are the most common type of mountain in the world. Some of the most famous ranges are the Himalayas, Andes and Alps.The Himalayas stretch through the borders of China, India and Pakistan, in Asia. The crust beneath the Himalayas is still being folded. Here, the Indian tectonic plate is pushing into the Eurasian plate.The Andes are the world's longest mountain chain. They stretch along the west coast of South America. Here, the Nazca plate is moving down below the South American plate. The Andes are mostly being folded up from the rocks of the South American plate.The Alps stretch across Italy, Austria and France, in Europe. Here, the tiny Adriatic microplate is crashing into the much larger Eurasian plate. The mountains include rocks that were once part of the ocean floor. They were lifted up in the process of folding.Not all fold mountains are tall peaks. For example, the Appalachians in North America are low, gentle slopes. Long ago, the Appalachians were taller than the Himalayas. The mountains were worn down over millions of years and now they are much smaller.Folds Are Classified By Their ShapeFold mountains are defined by complex rock formations known as folds. There are many different types of folds. Scientists usually classify them by their shape. Do they have sharp turns or gentle curves? Do they fold inward or outward?A fold mountain usually has more than one type of fold. Anticlines and synclines are the most common folds. An anticline is shaped like a question mark. The oldest rocks are located in the center of the fold. A syncline is shaped like the letter "U." The youngest rocks are located in the center of the fold.Domes and basins are often considered types of folds. A dome is a series of symmetrical anticlines. It is roughly shaped like half a sphere. Like an anticline, the oldest rocks in a dome are found in the center. A basin is a dip in the Earth's surface. Like a syncline, a basin has its youngest rocks in its center.Other types of fold include:Monoclines - In a monocline, all rock layers dip in the same direction. Chevron - A chevron is a fold in which rock layers look like zig-zags.Slump - A slump fold is the result of slope failure, a type of landslide. The slope failure happened when sediments were soft. This occurred before they became a single mass of rock. Sediments are smaller pieces of matter, like dirt, that settle in an area. As the sediments turned into stone, they became a slump. A slump fold mountain looks like a winding road.Ptygmatic - Ptygmatic folds are a type of slump fold. They are created where the folding material is less solid than the material around it. Melted rock sometimes pushes into other rock layers. This creates a ptygmatic (intestine-looking) fold.Disharmonic - Disharmonic folds describe mixed rock formations. Here, different rock layers have different fold shapes. So one might have a winding road AND ptygmatic (intestinal-fold) features to it.FAST FACTS:Persian Gulf is a Foreland BasinFold mountains are sometimes found beside foreland basins. These are dips in the earth that run alongside the mountains. The Ebro Basin in Spain is one example. It is a foreland basin that formed with a chain of mountains called the Pyrenees. Another example of a foreland basin is the Persian Gulf. It formed when the Arabian and Iranian plates created the Zagros Mountains. Main IdeaFill-In-The-BlanksEvery article has a main or central idea; sometimes it is even in the title or the first paragraph. It answers the question, "What is the overall passage about?" You must spell the word correctly to get it correct. Fold mountains are the result of Earth's tectonic plate movement. Supporting DetailsFill-In-The-BlankNow, you need to find details in the passage that support the Main Idea. You must spell the word correctly in order to get it correct. "Fold mountains are created where two or more plates are pushed together.""Fold mountains are created through a process called orogeny.""Here, the tiny Adriatic microplate is crashing into the much larger Eurasian plate." Matching: Fold Shapes Match the fold shape name with it's correct description. Anticline Shaped like a question mark with oldest rocks found in the center of the fold. Syncline Shaped like the letter "U" and the youngest rocks are located in the center of the fold. Dome A series of symmetrical anticlines and roughly shaped like a sphere. Basin A dip in the Earth's surface and has its youngest rocks in its center. LABEL THE IMAGES Label the image with the correct type of fold formation. You must spell it correctly (no capital letters) to get it correct.Word Bank: ptygmatic, disharmonic, slump, chevron chevron ptygmatic disharmonic slump MATCHING: Famous Mountain Ranges Match the famous mountain range with its description of plate movement. Himalayas Indian tectonic plate is pushing into the Eurasia plate. Andes Nazca plate is moving down below the South American plate. Alps Adriatic microplate is crashing into the much larger Eurasia plate. These are fold mountains found next to the Ebro Basin in Spain. Andes Alps Pyrenees This a foreland basin that was formed when then Arabian and Iranian plates created the Zagros Mountains. Persian Gulf Spain Ebro Basin This is created when two or more plates are pushed together over a very long period of time. oceans valley fold mountains Interaction of Tectonic Plates Watch this video to know more about how tectonic plates interact.