Spelunkers Dig Virginia; Caverns Delve into History of Both Geology and Mankind

Article excerpt

Byline: Jen Waters, THE WASHINGTON TIMES

Andrew Campbell had a crazy idea: to find a cave magnificent enough that people would pay money to visit it. While working as a tinsmith duringthe late 1800s in Luray, Va., he started looking.

After several years of perseverance, on Aug. 13, 1878, he and friends stumbled upon a draft of cold air coming from a limestone sinkhole in western Luray. They dug and uncovered one of the largest caverns in the eastern United States, which today is known as Luray Caverns. And people are paying to see it.

"At first, he was the laughingstock of the community," says John Shaffer, director of public relations at Luray Caverns. "It was like looking for a gold mine. Once in awhile someone finds one, but not too often. ... It just shows that sometimes, if you have a dream, it's not so far out of reach."

Caverns - cavities under the ground that usually are large enough for people to enter - are natural wonders of the world, and although they are in constant change, they still chronicle the history of their landscape.

About 400 million years ago, in the area that is now Luray Caverns, the organic remains of dead marine animals drifted down and accumulated on the bottom of what was then an ocean and eventually formed limestone, Mr. Shaffer says.

In time, the primal sea receded and exposed its bottom to acidic rains, which began seeping in and eating away at the soft stone. The erosion - at a pace of about one-tenth of an inch of limestone a year - formed underground chambers, most the size of a closet, but some as large as a convention center.

While the large amounts of rainwater have long since subsided, small amounts of seepage have continued to drip into the caverns. Drops of water that fall through cracks of limestone find their way into the caves. As they evaporate, the water droplets leave tiny deposits of calcite, which is made of calcium carbonate and may take the form of a crystal. It is the most common mineral found in caves.

As calcite builds upon itself on the ceiling, stalactites are created and hang down like stone icicles.

When the drops of water fall from the ceiling to the floor and evaporate, stalagmites start to grow.

When stalactites and stalagmites meet, columns or pillars take shape.

These formations grow more or less at the rate of one cubic inch every 120 years.

Luray Caverns' array of textures and colors is caused by the mineral content of the soil. Because they are located in an area with high iron content, many of the caves have a reddish or orange tint. Manganese in the soil creates shades of gray or brown. Calcite gives a pure white color.

"Nature decorates a cavern," Mr. Shaffer says. "It's remarkable how nature can extract minerals from the soil to paint these creations."

* * *

Shenandoah Caverns near Mount Jackson, Va., feature some of the most beautiful sights God has designed, says general manager Joe Proctor.

In the part of the caves named Cascade Hall is a calcite crystal formation called Diamond Cascade. One of the largest stalagmites in the caverns, called Cardross Castle, resembles the castle of the same name near Cardross, Scotland.

Several youths discovered the Shenandoah Caverns in 1884 during the construction of the Valley Division of the Southern Railway. A blast created a crevice in the ground; water vapor escaped and caught the attention of a group of boys. They thought they had found a source of water. Instead, they found caverns.

Shenandoah Caverns opened to the public in 1922.

Because caverns are not affected by daily temperature changes, most visitors wear jackets while exploring, even in the summer. Anywhere in the world, a cave's temperature is the average annual temperature of the area in which it is located. …