The Fascinating World of Speleology: Exploring the Depths of the Earth Geology is the study of the Earth, its composition, and the processes that have shaped it over millions of years. One of the most intriguing branches of geology is Speleology, the study of caves and other subterranean environments. Speleology, also known as spelunking or caving, involves exploring and studying caves, underground rivers, and other underground spaces. These are formed by the natural processes of erosion, dissolution, and sedimentation.