Most of the mountains that we see today have derived their names from the methods of their formations. Formation of mountains by the tectonic processes is known as "orogeny". It is a Greek word meaning; oros stands for "mountain" and genesis for "origin" or "creation". Our Earths' surface constitutes six pieces of Earth's crust and uppermost mantle, together referred to as the "lithospheric plates" or "tectonic plates". The crustal rocks are buried to tremendous depths and face hydrodynamic forces and tension. Volcanic eruptions, folding and buckling of the Earth's surface has resulted in 5 different types of mountains. They are Fold Mountains, Volcanic Mountains, Dome Mountains, Plateau Mountains and Block Mountains. Most of the mountains are formed due to the slow and gigantic movement.
Block Mountains or Fault Block Mountains are massive in structure. They have very steep slopes. Generally, the topography of the Block Mountains is very smooth. They are usually tucked in the folded zones of some of the most primitive mountains. These folded zones have gradually lost their plastic properties. And as a result, mountain surfaces have been smoothened because of denudations. Tectonic actions continued and eroded these sections. After breaking, some of the sections rose to new ranges and horsts. The remaining sunk to form depressions and grabens. Due to the repeated actions of orogeny, they formed broad gently sloping folds. These folds were accompanied by faults. Lifted type Block Mountains has two steep sides exposing scarps on both the sides.
Before understanding the formation process of fault Block Mountains, we must first understand "faults". The cracks formed on the Earth's surface are called "faults". These pieces fit like a puzzle mosaic. Due to tectonic or seismic movements, these gigantic puzzle pieces moves. As a result, block of rocks gets displaced on either side of these faults. They can get tilted sideways or can be uplifted with incredible force. And on the other side of the fault the ground undergoes a depression. However, in due course of time, these depressions get filled with weathering and erosion debris. There are two formation theories of Block Mountains.
There are two types of Block Mountains: Lifted and Tilted. Lifted type Block Mountains has two steep sides. Both side scarps are exposed. Sierra Nevada and Teton Mountains in Wyoming (North America) are the best examples of lifted type Block Mountains. Tilted type Block Mountains has one gentle slope. The other steep has an exposed scarp. These type of mountains are commonly seen in the Range and Basin region of the western United States, Rhine valley and south-central New England. Level block terrains are commonly seen in northern Europe.
Block Mountains support diverse species of flora and fauna due to its wide range of topographic features, temperature and precipitation.
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