Monday, June 20, 2011

Karst Landscapes

KARST LANDSCAPE
Karst is a unique landscape when landscapes of rock which are solvable are dissolved and carried away in solution. This rock is usually limestone, marble or dolomite, which is made up of calcium carbonate. Rainwater, made acidic by carbon dioxide from the atmosphere and soil, slowly infiltrates cracks in limestone and marble, dissolving the rock and enlarging the openings. There is very little evidence of surface water in these types of landscapes because streams are usually underground. Karst topography structures from range from unusual surface and subsurface features ranging from sinkholes, vertical shafts, disappearing streams, and springs, to complex underground drainage systems and caves
Karst landscapes take thousands of years to take formation. The earliest stages of Karst Landscapes the surface area is dry. The stream travels underground through cracks in the surface called sinkholes. Sinkholes form either from beneath the surface or from the surface down. Collapse sinkholes form when the limestone is dissolved away from below, removing the support for the surface and it collapses in.  Collapse sinks can be particularly dangerous because one might not know that the support for the surface under their feet is being slowly eaten way. Sinkholes can also be created where water infiltrates into the surface widen the fissure into which it flows. These sinkholes are called dolines

How Karst is Formed – “The Carbon dioxide Cascade”

As rain falls through the atmosphere is pick up CO2 , which dissolves in the droplets of precipitation. When the precipitation reaches the ground it it soaks into the soil, it will infiltrate cracks in the rocks. This water and CO2 forms a solution of carbonic acid: H2O+CO2=H2CO3. This water chemically breaks down the calcium carbonate and carries it away in solution. Over long periods, with a continuous supply of CO2 - enriched water, carbonate bedrock begins to dissolve. Openings in the bedrock increase in size and an underground drainage system begins to develop, allowing more water to pass, further accelerating the formation of karts. Eventually this leads to the development of subsurface caves.







KARST LANDSCAPE
Karst is a unique landscape when landscapes of rock which are solvable are dissolved and carried away in solution. This rock is usually limestone, marble or dolomite, which is made up of calcium carbonate. Rainwater, made acidic by carbon dioxide from the atmosphere and soil, slowly infiltrates cracks in limestone and marble, dissolving the rock and enlarging the openings. There is very little evidence of surface water in these types of landscapes because streams are usually underground. Karst topography structures from range from unusual surface and subsurface features ranging from sinkholes, vertical shafts, disappearing streams, and springs, to complex underground drainage systems and caves
Karst landscapes take thousands of years to take formation. The earliest stages of Karst Landscapes the surface area is dry. The stream travels underground through cracks in the surface called sinkholes. Sinkholes form either from beneath the surface or from the surface down. Collapse sinkholes form when the limestone is dissolved away from below, removing the support for the surface and it collapses in.  Collapse sinks can be particularly dangerous because one might not know that the support for the surface under their feet is being slowly eaten way. Sinkholes can also be created where water infiltrates into the surface widen the fissure into which it flows. These sinkholes are called dolines

How Karst is Formed – “The Carbon dioxide Cascade”

As rain falls through the atmosphere is pick up CO2 , which dissolves in the droplets of precipitation. When the precipitation reaches the ground it it soaks into the soil, it will infiltrate cracks in the rocks. This water and CO2 forms a solution of carbonic acid: H2O+CO2=H2CO3. This water chemically breaks down the calcium carbonate and carries it away in solution. Over long periods, with a continuous supply of CO2 - enriched water, carbonate bedrock begins to dissolve. Openings in the bedrock increase in size and an underground drainage system begins to develop, allowing more water to pass, further accelerating the formation of karts. Eventually this leads to the development of subsurface caves.




Cave feature:
Stalactites are deposits of calcium carbonate which hang from the ceilings of caves and stalagmites are formed from deposits of calcium carbonate on cave floors.When the stalactites and stalagmites combine they form a pillar. Flowstone forms as calcium carbonate deposits are left behind as the undergrounds as streams flow through the cave.







Karst Features:

In the early stages of karst topography,, the surface is dry and there is no apparent streams of top water. The next stage, dips and depressions form and can be seen because of the formation of underground caves. As the caves collapse because the support of over laying rock is minimized, sink holes and large depressions may form. The mature karst stage, sink holes may combine and form one large one called an uvala. A gorge like feature can form called a poljes when the entire cave system collapses. Leftover pieces of rock are called hums.





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