Final answer:
Old-Earth geologists rely on chemical reactions of carbonic acid with limestone and the physical erosion by water to form solution caves. Over time, evaporating water rich in calcium carbonate minerals deposits stalactites from ceilings and stalagmites from the floor, creating the cave's iconic features.
Step-by-step explanation:
Old-Earth geologists rely on chemical reactions and the physical processes of water erosion to explain the formation of solution caves. These caves typically form in areas rich in limestone (CaCO3). Acidic water containing dissolved CO2 (carbonic acid) seeps into the ground and reacts with the limestone, gradually dissolving it and creating voids that can eventually turn into caves.
Over extended periods, water continues to transport dissolved minerals into these caves. As the water droplets hang from the cave ceiling and evaporate, they leave behind deposits of CaCO3, forming stalactites hanging from the ceiling. Similarly, when water drops to the floor, it deposits CaCO3, forming stalagmites.
This process is an example of pH-dependent solubility equilibrium and can result in various cave formations, including the impressive systems found in Carlsbad Caverns National Park and Lechuguilla Cave.