A Moment of Science

Mount Rainier And Its Strange Lava

There's a mystery happening along the slopes of Mount Rainier in Washington State.

Mount Rainier

Photo: Dryad & Sprite Photography (Flickr)

The lava mystery will soon be solved!

Today’s mystery concerns geological formations along the slopes of Mount Rainier in Washington State.

Mount Rainier is a volcano, so we aren’t surprised to see hardened lava flows left over from past eruptions. We are surprised to see these flows sticking to high ridges and hilltops, ignoring deep valleys to either side.

If molten lava flows like other liquids, we’d expect it to follow the path of least resistance and flow down into valleys.

Why Didn’t The Lava Do This?

We can solve the mystery of the mountain-climbing lava through investigation. For decades, the prevailing theory of how these features formed went something like this: Long ago, when the molten lava first poured out of the volcano, those hill tops were the bottoms of low-lying valleys.

Over eons, flowing water carved new valleys to the sides of the hardened lava. The hard lava didn’t erode as much as the surrounding rock, eventually giving the landscape the appearance it has today.

Think about pouring hot candle wax down a channel in a hill of sand, then blowing away some of the sand after the wax has hardened.

Can This Explain These Mysterious Features?

Unfortunately, no. For that theory to work, the lava flows would have to be much older than they are. Dating of the hardened lava reveals that it might even be as young as the most recent ice age.

Can you solve the mystery of the mountain-climbing lava? Tune in to our next program for the solution!

Stay Connected

What is RSS? RSS makes it possible to subscribe to a website's updates instead of visiting it by delivering new posts to your RSS reader automatically. Choose to receive some or all of the updates from A Moment of Science:

Support for Indiana Public Media Comes From

About A Moment of Science

Search A Moment of Science