Cavers Exploring Lechuguilla, Second Deepest Cave in Nation
CARLSBAD, N.M. (AP) _ A shrieking wind, sometimes clocked at more than 50 mph, greets a visitor at the entrance to the latest underground discovery in sprawling Carlsbad Caverns National Park.
The wind’s force inside the 20-foot, steel-lined shaft descending into Lechuguilla Cave is enough to blow an explorer’s pack out of his grasp and fill his eyes with dirt and debris.
But the challenge of descending a rough iron ladder into the bowels of Lechuguilla Canyon is rewarded with nearly 30 miles of what many cavers call the most beautifully decorated passages in the country.
Lechuguilla’s passages, discovered in 1986 when a crew following the whistling wind dug through rock that had collapsed inside the cave, are now the second deepest recorded in the U.S., at 1,501 feet.
Curling like snakes from the high, domed ceiling of the Chandelier Ballroom are selenite stalactites which geologists call the world’s largest. Surveyors in the room, about 1,000 feet below the surface, had to devise a new symbol for them on their maps.
Up to 20 feet long, the chandeliers’ large trunks terminate in branching, claw-like arms of translucent selenite crystal. Several dozen of them grow from the ceiling of the 300-foot-long room.
″In terms of the overall geology, speleogenesis and unique speleothems, Lechuguilla is the most important discovery in the U.S. in the last 20 years,″ said Dave Jagnow, a New Mexico geologist and chairman of the scientific advisory committee for the Lechuguilla Cave Project.
Speleogenesis involves the study of how caves form in limestone and other soluable rock, while speleothems include the stalagtites and stalagmites that grow from the ceiling and floor of passages and rooms.
Hundreds of explorers from the National Speleological Society have been exploring and mapping Lechuguilla for 1 1/2 years. The cave has sparked renewed efforts by the Huntsville, Ala.-based society for federal legislation creating ″cave wilderness,″ a proposal supported by the National Park Service.
No cave has yet been declared a wilderness area. But Congress in 1988 passed a federal cave protection act after lobbying by the Speleological Society, the largest caving group in the U.S. with more than 7,500 members, and other conservation groups.
Park personnel were surprised when exploration showed Lechuguilla surpassed both the length and depth of the more-famous Carlsbad. The 21-mile-long cave for many years was considered the nation’s deepest, at 1,037 feet.
″When I first became associated with the park in the 1950s, everyone thought Carlsbad had been fully explored,″ said Bobby Crisman, superintendent of the park in southeastern New Mexico. ″But since that time, another one- third of the cave was found and Lechuguilla was dug open.″
Geologists said both caves were formed when slightly acidic water and other chemical action created voids in the ancient Capitan Reef system, formed millions of years ago by an inland sea.
Based on volumetric and other studies, cavers may someday find another subterranean system in the 46,755-acre park that could connect with Carlsbad, Lechuguilla or Big Manhole Cave, explorers said.
″Everyone thought Carlsbad was an abnormality″ with its deep passages, said Richard A. Bridges of Denver, co-director of the Lechuguilla Cave Project.
″Now, when you look at Lechuguilla, most of its passage lies from 900 to 1,100 feet deep,″ he said. ″There is a lot of passage development at those levels and they are several hundred feet below the deepest canyons at the park. And Manhole is also blowing a lot of air.″
Lechuguilla’s 90-foot entrance drop is 3 1/2 miles west-northwest of Carlsbad Cavern. Manhole is less than 1 mile north of the farthest reaches in Lechuguilla’s Rift, a slanting fault or geological joint in the rock several hundred feet high and only a few feet wide.
In a 1987 volumetric study based on air and barometric measurements, caver Bruce A. Zerr of Harriman, Tenn. estimated Lechuguilla would yield 864 miles of passage.
″That study is off by an order of magnitude, because it is also detecting the microporosity the cave rock is tapped into - the fractures and small spaces,″ said Jagnow, of Los Alamos, N.M. ″The current cave is 29 miles but I would estimate we will find in excess of 50 miles of passage.″
Bridges, 36, said Lechuguilla was still yielding its secrets to cavers during the most recent expedition in January.
Discoveries of unexplored passages - one dubbed ″High Hopes″ and another identified as the upper level of ″Apricot Dome,″ pushed Lechuguilla to seventh longest among U.S. caves.
″Certainly, the excitement level of the exploration of such a diverse cave is unprecedented in the park since (discoveries at) Carlsbad Cavern,″ said Ron Kerbo, Park Service cave specialist at Carlsbad.
″It has been a long time since mineralogical finds of that magnitude have been made at the park,″ he said.
British cavers have described the activity as ″mountaineering in reverse.″ Using ropes and climbing equipment, about 330 cavers from 38 states and five foreign countries have safely descended Lechuguilla’s multiple pits and steep slopes to the 1,501-foot depth. By comparison, the Sears Tower in Chicago, the nation’s tallest building, soars just 1,454 feet.
Wyoming’s Columbine Crawl, at 1,550 feet, is the deepest cave in the U.S., according to Speleological Society records.
Known since 1914, Lechuguilla had been mined for bat droppings, or guano, but was not considered by park officials to be a significant cave.
But a digging team broke through during the Memorial Day holiday of 1986 and a 24-inch-wide culvert was installed to stabilize a permanent entrance.
Named for the sharp-spined plant that can stab the legs of unwary hikers, Lechuguilla contains a 150-foot pit called Boulder Falls for its tendency to dislodge rocks as cavers negotiate it.
Below the drop, the cave initially stopped explorers with a confusing jumble of boulders at the Rift until an upper-level Rift Overpass was discovered.
The shortcut trimmed the Rift journey from 3 1/2 hours to about 20 minutes, although explorers had to negotiate Freakout Traverse over a 90-foot drop.
Explorer Roy Glaser of Denver watched in horror as a 6- by 3-foot limestone slab began moving toward the pit when he first crossed it.
Luckily, the movement stopped after 6 inches.
″He said he imagined himself in a Road Runner cartoon like the coyote, falling 90 feet to the floor and being flat-rocked,″ quipped Bridges.
Park Service officials allow no more than 20 people at a time to explore the cave. The limitation minimizes human impact and helps preserve and protect the nonrenewable resource.
″How we treat the cave when we explore it will not just be looked on by other cavers, but will instill in the public a respect and admiration for its beauty,″ said Bridges.
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