How are caves formed?

Caves and caverns are carved in cool and secret darkness. They may be small enough to shelter a dog or as large as a cathedral. Small rooms may open one into another or connect with passageways, Steep cracks may lead down from the surface to the buried cave system or the entrance may be a rocky doorway in the side of a hill,

A large system of dark and silent caves is like an underground city. It is a great temptation to explore the wonders of these buried secrets .. but no sensible person attempts this adventure on his own. For caves are full of buried booby traps. Spelunking, or cave exploring, is a job for experts and the rest of us must be content to enjoy and admire the cave systems that have been tested and nude safe for visitors.

There are many cave systems provided with lights and experienced guides, We can enjoy these underground cities in safety and hear them described. Some of the rooms may be adorned with rocky carvings. Wavy draperies may festoon the walls. Stalactites may dip frozen the ceilings like hanging icicles. Stalagmites may poke up from the floors in spikes or rounded domes. Graceful pillars may reach from tr.e floors to the lofty roofs   and all this elegant carving is made from stony minerals.

The inside of a cave is always cool and damp and somewhere we are almost sure to find water. It may cascade down from an underground waterfall, gurgle along as a buried stream, wait in a quiet pool or merely seep down the stony walls. The constant dripping of water, we Ere told, will wear away the hardest stone. Most caves are carved out of the earths crust by the drip dripping of running and seeping water.

In time, running water dissolves chemicals    from the hardest rock. Chemicals in rocks such as limestone dissolve very easily, which is why most of our big cave systems are carved into the buried layers of limestone hills. Here rain water seeps down through the surface, stealing chemicals and licking out cracks which weaken the rocks. The cracks are nibbled bigger by the seeping ground water from showers, Holes are eaten away from weakened rocks below the surface and gradually a cave system begins to grow.

Caves made by dripping water are often embroidered with rocky stonework, This water is loaded with dissolved chemicals and in the cool, underground caverns it tends to evaporate. The chemicals, however, stay behind. These mineral fragments settle together and form solid rock again, And bit by bit they are shaped into graceful stone work by the path of the seeping water.