Orogeny
The Process of Mountain Building
Complexity of Mountain Formations
How do mountains form? They may seem to appear overnight, but in reality their process of forming occurs over a long period of time. This can happen for as long as millions of years. Mountain belts extend for hundreds, or even thousands of kilometers, and their structures penetrate deep into the Earth. This makes their size, age, and formation process difficult to understand.
Fold Mountains
The first step in the process of folding is the converging of two plates converge. As one plate subducts beneath the other; the space between the two colliding plates closes. The continental crust; which is lighter than oceanic crust, can not be subducted. Instead, as the continents collide, the crust thickens and is forced upward. This makes the plates fold, hence the name of the process. This keeps occurring until we get the mountain formation we know of today.
Block Mountains
When it comes to the blocking method of the way mountains form there are two main theories that people choose to believe. The first theory is called the tension theory. According to this theory, a weak point existed on Earth This point experienced a great amount of tension. This tension radiated from that point and pushed the side rocky crust. As a result, the side rocks went down; and in the middle, the central block remained stagnant along with the point of tension. This caused the central block to form at a higher elevation than the blocks on the side. The second theory is called the compression theory. In this theory it is said that the rock layers compress the middle block. Due to this compression, the middle block rose forming the block mountains. The middle chunk remained at a higher elevation than the side rock chunks.
Volcanic Mountains
Volcanic Mountains are formed when molten rock (magma) deep within the earth, erupts, and piles upon the surface. Magna is called lava when it breaks through the earth's crust. When the ash and lava cools, it builds a cone of rock. Rock and lava pile up, layer on top of layer.
Sources
- http://www.summitleaders.org/wp-content/uploads/2010/09/Kili-Large-Slider-900x435.jpg
- http://www.factmonster.com/images/ESCI214MOUBUI002.gif
- http://www.innovateus.net/climate/what-are-block-mountains#What+are+the+theories+of+formation+for+the+Block+Mountains%3F
- https://classconnection.s3.amazonaws.com/754/flashcards/1160754/png/fault_block_mountains1328630070755.png
- http://www.primaryhomeworkhelp.co.uk/mountains/types.htm
- http://3.bp.blogspot.com/-QiQnFFCRGqE/UWGZB1BJDlI/AAAAAAAAKBk/g4vw4UrE9EI/s1600/volcano.jpg