Jerry Nance., age 12, of Bryan, Texas for the question:

Are the oldest mountains the tallest?

A mountain  grows up and grows old so slowly that we would notice no difference, even in a hundred human lifetimes, Chances are, it grows from a long ditch of shallow sea water called a geosyncline. Where our proud Rockies now stand there was such a geosyncline 150 million years ago. At this time, the Sierra Nevada Mountains to the west were already in place. The southern Appalachians are 100 million years older and the Appalachians of New England date back some 300 million years.

All these mountains are very old according to our standards. But, as mountains go, they are in the prime of life. The Caledonia Mountains of Greenland, Scandinavia and Great Britain are almost a 100 million years older than the oldest Appalachians. They have passed their prime and worn down so that in some places only their bases remain. Still older are the Killarney Mountains of Canada, Minnesota and Wisconsin. The aging process here was helped along by the cruel glaciers of the Ice Ages.

The oldest mountains in the world are now no more than a series of gentle hills. They are the Laurentian Mountains of eastern Canada. So, we see, the oldest mountains are not the tallest ones. The world is tallest mountains are the snow capped Himalayas of Asia. These lofty peaks are among the world •s youngest mountains and they are still growing. The Alps, the Pyrenees, the Apennines, the Himalayas and the Caucasus mountains have all grown from nothing in the past 60 million years. By mountain standards, they are mere babies. The lofty Andes are about the same age as the Rockies.

A mountain grows because of pushes and stresses in the earth's crust. Its entire life is one continuous struggle with the wind and the weather.

This warfare begins as soon as the mountain poles up its nose. The rain beats at it, washing down loose dirt. Heat and frost crack its rocks and break them into small, moveable pieces.

For a long, long time, the mountain grows faster than the elements can wear it away. It may stop growing for a while, in which case some of its tall peaks are worn down a little: Our Rocky Mountains have had several such ups and down in their long history.

Finally, the mountain reaches its full size. But the warfare with the elements continues. Century by century, the proud peaks are worn away. After several hundred million years, the lofty range is no more than a series of gentle hills. The Rockies may once have been much taller and the Appalachians certainly were. And we have no idea how tall the Killarney Mountains and the ancient Laurentians once were.