Science

Cavern Formation

It all began with a drop of water. A shallow inland sea covered this area 330 million years ago, depositing layers of sediment that eventually hardened into limestone. Millions of years later this Escabrosa limestone along with other rock layers uplifted to form the Whetstone Mountains. The Escabrosa limestone, due to a type of tremor or fault, down-dropped thousands of feet relative to the mountains above.

Rainwater, made slightly acidic by absorbing carbon dioxide from the air and soil, penetrated cracks in the down-dropped limestone block and slowly dissolved passages in it. Later, lowering groundwater levels left behind vast, air-filled rooms.

Kartchner Caverns' wide variety of decorations, called “speleothems,” began forming drop by drop over the next 200,000 years.

Water seeping from the surface dissolves minerals on its trip through the limestone. Once it reaches the cave, the trapped carbon dioxide escapes from the water. No longer able to hold the dissolved calcite, the drop deposits its tiny mineral load. Over time, these minerals have created the beautiful speleothems and variety of colors found in the cave. Kartchner Caverns is a “living” cave; the formations are still growing!

Bats and other Cave Creatures

During the summer months, the cave's Big Room serves as a nursery roost for over 1,000 female cave myotis bats. The pregnant females return to Kartchner Caverns around the end of April, where they give birth to a single pup in late June. The babies remain in the roost each evening while their mothers forage for insects in the surrounding countryside. During the summer the colony consumes about half a ton of insects, consisting of moths, flying ants, beetles, mosquitoes and termites. Mothers and their offspring will leave mid-September, to begin their migration for their winter hibernation roost. These bats provide the only link between the ecosystem of the cave and the surface.

After returning to the bat roost from their nightly forays, the bats excrete waste, forming large guano piles. Most of the other life forms found in the cave depend on these guano piles for their food. Fungi and bacteria consume the guano first. These are in turn eaten by nematodes, mites, isopods, amphipods, and book lice. These are then eaten by spiders, scorpions, mites, millipedes, and centipedes. Scavengers, like crickets and beetle larvae, clean up the leftovers. The bats' guano provides the energy needed to run this complex food chain. For more information, read the Feature Story about Bats

Paleontology of the cave

While exploring the cave, paleontologists, those who study prehistoric life, uncovered an 86,000 year record of the local faunal community. The finds included the following: skeletons of an 86,000 year old Shasta ground sloth, a 34,000 year old horse, and an 11,000 year old bear, as well as terrestrial snails, a clam, a toad, lizards, rabbits, snakes, a coyote, a ringtail, and many species of rodents. These discoveries have lead paleontologists to declare Kartchner Caverns a treasure house of information on the local fossil history of the uplands around the San Pedro River Valley.

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Cavern Formation

Bats and other Cave Creatures

Paleontology of the cave