Carlsbad Caverns National Park was established to preserve Carlsbad Cavern and numerous other caves within a Permian-age fossil reef. The park contains 83 separate caves, including the nation's deepest limestone cave - 1,597 feet (486.8 m) - and third longest. Carlsbad Cavern, with one of the world's largest underground chambers and countless formations, is highly accessible, with both self-guided and a variety of ranger-guided tours offered year round. Visitors can hike into the interior rooms on their own via the natural entrance, or take an elevator (the exit for everyone) directly down into the center of the public cave area.
Carlsbad was first designated a National Monument on 25 October 1923. It was redesignated a National Park on 14 May 1930. Carlsbad Caverns was also designated a World Heritage Site on 6 December 1995.
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2 Bats 3 History of Carlsbad Cavern National Park 4 External link |
The story of the creation of Carlsbad Cavern begins 250 million years ago with the creation of a 400 mile long reef in an inland sea that covered this region. This horseshoe shaped reef formed from the remains of sponges, algae and seashells and from calcite that precipitated directly from the water. Cracks developed in the reef as it grew seaward. Eventually the sea evaporated and the reef was buried under deposits of salts and gypsum.
Then, a few million years ago, uplift and erosion of the area began to uncover the buried rock reef. Rainwater, made slightly acidic from the air and soil, seeped down into the cracks in the reef, slowly dissolving the limestone and beginning the process that would form large underground chambers. At the same time, hydrogen sulfide gas was migrating upward from vast oil and gas deposits beneath the ancient reef. This gas dissolved in the percolating ground water to form sulfuric acid. The added power of this corrosive substance explains the size of the passageways. The exposed reef became part of the Guadalupe Mountains and the underground chambers became the wonder of Carlsbad Cavern.
The decoration of Carlsbad Cavern with stalactites, stalagmites and an incredible variety of other formations began more than 500,000 years ago after much of the cavern had been carved out. It happened slowly, drop by drop, at a time when a wetter, cooler climate prevailed. The creation of each formation depended on water that dripped or seeped down into the limestone bedrock and into the cave. As a raindrop fell to the ground and percolated downward, it absorbed carbon dioxide gas from the air and soil, and a weak acid was formed. As it continued to move downward the drop dissolved a little limestone, absorbing a bit of the basic ingredient needed to build most cave formations--the mineral calcite.
Once the drop finally emerged in the cave, the carbon dioxide escaped into the cave air. No longer able to hold the dissolved calcite, the drop deposited its tiny mineral load as a crystal of calcite. Billions and billions of drops later, thousands of cave formations had taken shape. And, oh, the shapes they took! Where water dripped slowly from the ceiling, soda straws and larger stalactites appeared. Water falling on the floor created stalagmites. Sometimes a stalactite and stalagmite joined, forming a column.
Draperies were hung where water ran down a slanted ceiling. Water flowing over the surface of a wall or floor deposited layers of calcite called flowstone. Cave pearls, lily pads and rimstone dams appeared where pools of water or streams occurred in the cave. Like oyster pearls, cave pearls were made as layer upon layer of calcite built up around a grain of sand or other tiny object. Lily pads formed on the surface of pools, while dams formed where water flowed slowly on the floor. Another type of cave formation that decorated cave walls and even other formations was popcorn, which may have formed when water evaporated and left behind calcite deposits.
Some of the more unusual formations to occur in Carlsbad Cavern are helictites, which grow seemingly without regard to gravity, their twisting shapes governed by crystal shapes, impurities and the force of water under pressure. Other rare formations are those composed not of calcite, but of aragonite, a mineral chemically identical to calcite but with a different crystal structure. These formations tend to be small, delicate and needle-like.
Carlsbad Cavern is a sanctuary for about 1 million Mexican Freetail bats. During the day they crowd together on the ceiling of Bat Cave, a passageway near the natural entrance of Carlsbad Cavern. In the darkened home they are seen only by scientific researchers. At nightfall, however, the bats leave the cave in gigantic swarms. Silhouetted against the night sky like a dark, swift-moving cloud, the bats make their most dramatic display. Other extraordinary characteristics of the bat--its natural sonar system and its ability to fly--make this creature of darkness one of great interest.
Like most species of bats, Mexican Freetails navigate and locate their prey by emitting ultra-high frequency sounds. Known as echolocation, this natural sonar system is similar to that used by dolphins and whales. When a bat's signals strike an object, they are reflected back and heard by the bat. The bat then takes whatever action is appropriate, whether it be zeroing in on a tiny moth or swerving to avoid a tree limb.
As many as seven types of bats may roost in Carlsbad Cavern, but none is as prevalent as the Mexican Freetail. Gray or sometimes brown, this bat is distinguished by its long, narrow wings and a free-dangling, skinney tail. Only a part-time resident of Carlsbad Cavern, this migratory bat stays here, and in other Southwest caves, from early spring through October. It flies south to tropical Mexico for the winter
The Bat Cave serves as a warm weather home, as a daytime refuge, and perhaps most importantly, as a maternity roost, for Mexican Freetail bats. The bats migrate from Mexico to Carlsbad Cavern each year to give birth and raise their young. Under cover of darkness, away from predators or disturbances, the young are born in June. A female usually has just one offspring. Each birth occurs on the ceiling as the mother hangs by her toes and thumbs. The newborn, too, clings to the ceiling, or to its mother. For the next four to five weeks the youngster remains on the ceiling. During the day mother and young hang in clusters on the ceiling, resting, napping and nursing. As many as 300 bats may crowd into one square foot. At night, the young are left in the cave while the adults leave to feed. In July or August, each young bat takes its first flight, joining the adults on nightly feeding forays. Throughout their stay in Bat Cave the bats share their quarters with only a few insects and spiders. Finally in late October or early November, adults and young leave Bat Cave until next year for their wintering grounds in Mexico.
The spectacular night flight of the Mexican Freetail begins with a few bats fluttering out of the natural entrance of Carlsbad Cavern. Then, in a matter of minutes, a thick whirlwind of bats spirals out of the cave up into the darkening night sky. the exodus can last 20 minutes or as long as 2.5 hours. Once out of the cave the undulating mass of thousands of bats flies, in serpentine fashion, towards the southeast to feed in the Pecos and Black River valleys. Once there, they begin gorging themselves on moths and other night-flying insects. Using echolocation, its sophisticated sonar system, each bat may catch and eat several stomachfuls of insects in a single night. With the coming of dawn, the bats begin flying back to the cave individually or in small groups. They reenter the cave in a fashion almost as remarkable as their departure. Each bat positions itself high above the cave entrance. It then folds its wings close to its body, and plummets like a hailstone into the blackness of Carlsbad Cavern, making a strange buzzing sound as it does. One by one, the bats return to the safety of the Bat Cave, where they sleep until reemerging in the dusk of the next day.Geology - The Creation of the Cavern
The cave interior is decorated in an almost
endless array of spectacular limestone formations:
here a column and dozens of stalactitesA Cave is Decorated, Drop by Drop
Bats
Echolocation
The Mexican Freetail
In the Bat Cave
The Night Flight