Features Found in a limestone region includes
Sink holes, caves, stalagmites, stalactites, limestone pavement etc.
Explanation:
Limestone's are sedimentary rocks that are majorly composed of calcium carbonate(CaCO3). This rocks are mainly found under sea water where their is abundant of corals and reefs. This organism add more calcium carbonate to the rock during their activities and even when they die.
One important characteristics of calcium carbonate is it ability to dissolve in weak acid and this what makes limestone features unique. When their is plenty of rainfall the water easily reacts with the carbon dioxide(CO2) in the atmosphere to form a weak acid. This acidic water , if it comes with contact with calcium carbonate, it dissolves in it to form calcium bicarbonate solution. The chemical reaction is as follow ;
H2O(rainfall) + CO2(carbon dioxide) → H2CO3( weak carbonic acid)
H2CO3( weak carbonic acid) + CaCO3 → Ca(HCO)3(calciulm bicarbonate solution).
Features one would expect in region that has limestone bedrocks are caves, sinkholes, limestone pavement, stalagmites and stalactites.
Caves are underground features formed when weak carbonic acid seep through limestone fissures and bedding plane to carry along calcite(calcium carbonate) creating a cavern system along the process. This weak acid forms a solution with the Calcium carbonate rocks. The acid dissolve more of the limestone rocks to form a hollow pathway underground.
Stalagmites and stalactites are formed in caves . This features are formed when the Calcium bicarbonate solution loose the water and carbon dioxide content . The calcium carbonate is left behind as water and carbon dioxide are loss from the ceiling of the caves(stalactites, an ice like structure) and the floor of the cave(stalagmites, a cone like structure) . Stalagmites grows upward due to calcium carbonate laden water seeping from the ceiling of the cave to the floor . Stalactites grows downward due to the Calcium bicarbonate solution coming from the roof and later loss water and carbon dioxide living the calcium carbonate behind.
Sink holes are depression caused when water dissolves limestone . Sink holes are usually cylindrical holes . The accumulated water in the limestone are then drained causing a depression.
Sink hole can also be formed if solution of the limestone creates a depression on the surface of the limestone.
when you have sink holes and caves in an area , it is called Karst topography.
