Brian Lake, age 9, of Las Cruces, N.M., for his question:

HOW WERE THE CARLSBAD CAVERNS FORMED?

Carlsbad Caverns, a chain of huge underground caves in southeastern New Mexico, became a national park in 1930. Deep under the earth's surface are some of the world's most spectacular stalactites and stalagmites.

Scientists tell us that the limestone in Carlsbad Caverns most likely formed in a shallow inland extension of the ocean about 200 million years ago. Then, when the Rocky Mountains were formed about

'60 million years ago, the caverns probably rose above sea level and water began hollowing out the limestone to form the caves.

One large chamber, called the Big Room, is 4,000 feet long and 625 feet wide. At one point the ceiling is 285 feet high.

Rocks within the caves form shapes that look like Chinese temples, pillars and lacy icicles.