Caves

Caves :-

Caves commonly form in areas of limestone , although on coastlines they are also occur other rocks . limestone is made of calcite . which dissolve in the carbonic acid naturally present in rain water , and in humin acids from the decay of vegetation . the acidic water trickle down through cracks and joints in the limestone and between rock layers breaking up the surfaces terrain into clints (blocks of rock), separated by grikes (deep crack) , and punctuated by sink holes (also called swallow holes or potholes) into which surfaces streams may disappear . underground , the acidic water dissolve the rock around cervices opening up a network of passages and caves , which can became large caverns if the roofs collapse . various features are formed when the dissolved calcite is redeposited : for example , it may be rediposited along an underground stream to form gour (series of calcilite ridges) , or in caves and passages to form stalactites , stalactites develop where calcite is left behind as water drips from the roof; where the drops land, stalagmites build up