(Answer to question 1 ) Groundwater percolating through the zone of aeration dissolves the carbonate rock and enlarges its
fractures and bedding planes. On reaching the water table, the groundwater migrates to the surface.
The groundwater continues to dissolve rock in the zone of saturation and forms a system of horizontal
passageways. The surface streams erode deeper, the water table drops, and a new set of passageways
begin to form. The water abandons the channel ways and leaves a set of caves and caverns
(Answer to question 2 ) Karst develops by groundwater erosion in areas underlain by soluble rocks. Karst is usually created by
limestone. The topography is characterized by numerous caves, springs, sinkholes, solution valleys,
and disappearing streams.
(Answer to question 3 ) Most groundwater naturally contains some carbonic acid and is slightly acidic. The water becomes
acidic when it combines with carbon dioxide (CO2) from the air or decaying organic matter. The
chemical reaction is H2O + CO2 H2CO3.
(Answer to question 4 ) Stalactites are dripstone formations shaped like icicles that hang from the roof of a cave. Stalagmites
are dripstone formations that project upward from the floor of a cave. They form in pairs because they
are from the same dripping source and the two may continue growing until they merge.
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