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    :Waterfalls redirects here. For the Paul McCartney single, see Waterfalls (Paul McCartney song).


    A waterfall is usually a geological formation resulting from water, often in the form of a stream, flowing over an erosion-resistant rock formation that forms a sudden break in elevation. Waterfalls may also be artificial, and they are sometimes created as garden and landscape ornament.

    Some waterfalls form in mountain environments where erosion is rapid and stream courses may be subject to sudden and catastrophic change. In such cases, the waterfall may not be the end product of many years of water action over a region, but rather the result of relatively sudden geological processes such as thrust faults or volcanic action.

    The hobby of falls bagging is blossoming in many parts of the world.


        Waterfall
            Formation
            Types of waterfalls
            Examples of large waterfalls

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    Formation





    Typically, a stream flow across an area of formations strata will form shelves across the streamway, elevated above the further stream bed when the less erosion-resistant rock around it disappears. Over a period of years, the edges of this shelf will gradually break away and the waterfall will steadily retreat upstream, creating a gorge of recession. Often, the rock strata just below the more resistant shelf will be of a softer type, meaning undercutting, due to splashback, will occur here to form a shallow cave-like formation known as a rock shelter (also known as a rock house) under and behind the waterfall. Eventually, the outcropping, more resistant cap rock will collapse under pressure to add blocks of rock to the base of the waterfall. These blocks of rock are then broken down into smaller boulders by attrition as they collide with each other, and they also erode the base of the waterfall by abrasion, creating a deep plunge pool.

    Waterfalls can also form due to glaciation, whereby a stream or river flowing into a glacier continues to flow into a valley after the glacier has receded or melted. The large waterfalls in Yosemite Valley are examples of this phenomenon.

    Streams become wider and more shallow just above waterfalls due to flowing over the rock shelf, and there is usually a deep pool just below the waterfall due to the kinetic energy of the water hitting the bottom.




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    Types of waterfalls
    Block
    Water descends from a relatively wide stream or river.

    Cascade
    Water descends a series of rock steps.

    Cataract
    A large waterfall. See Cataracts of the Nile for a well-known sequence of six.

    Fan
    Water spreads horizontally as it descends while remaining in contact with bedrock.

    Horsetail
    Descending water maintains some contact with bedrock.

    Plunge
    Water descends vertically, losing contact with the bedrock surface.

    Punchbowl
    Water descends in a constricted form, then spreads out in a wider pool.

    Segmented
    Distinctly separate flows of water form as it descends.

    Tiered
    Water drops in a series of distinct steps or falls.

    Multi step
    A series of waterfalls one after another of roughly the same size each with its own sunken plunge pool.


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    Examples of large waterfalls


      Gocta, the fifth highest in the world at 771 m (2533 ft), located in the province Chachapoyas, Peru
      Niagara Falls, most voluminous in North America, on the border between the United States and Canada
     
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    This article is licensed under the GNU Free Documentation License [copyleft]. It uses material from the Wikipedia article "Waterfall". link