Caves !

Gypsum Caving

Gypsum is another soluble rock that can be disolved by acidic waters traversing fractures. This type of cave can form in geologically very very short periods of time and is much less stable.
Exploring National Park and Monument Caves

Many of these caves offer a "spelunking" tour. Of course not everyone can get through all the passages.

In this picture taken at Jewel Cave National Monument in South Dakota, a would-be cave explorer tries her luck at the cement block that matches the smallest passage on the spelunking tour. (Its 24 inches wide by 8.5 inches high)
Extra Feature:

One of the unusual features of certain "mixing zone" caves is the presence of cusp-shaped water caused indications known as "scallops."
Click here for an article on large or "mega-scallops" in Cave of the Winds near Manitou Springs, Colorado

Copyright (c) 2001-04 by R. Mark Maslyn
Last Updated Sept. 19, 2004