The Basin is one of the world's largest underground water supplies. Trapped under layers of impervious shale are beds of sandstone saturated by hot water. Through bore holes up to 1,400 m deep, hot water is forced to the surface by hydrostatic pressure. Natural cracks in the have led to the formation of mound springs where sediments brought up with the water form small hillocks, not unlike volcanoes.
 |
 |
| Continue Tour | Return to SA Map |