(upbeat music) - [Narrator] What does it mean to be curious?

For my students, curiosity creates opportunities for a bigger and brighter future.

(dramatic music) - Well, here's a question for you.

Can you think of the oldest bedrock in the North Cascades of Washington?

What's your guess?

Is it the granite of Washington Pass or the sandstones of the Methow Valley?

Maybe the green schist of Mount Shuksan.

No, it's right here at Yellow Aster Butte.

Beautiful metamorphic gneiss, 400 million years old, and it came from Northern Europe.

(upbeat music) (upbeat music) Full day of hiking today, Yellow Aster Butte Hiking Trail and Mount Baker volcano.

I mean, it doesn't get much better than this.

And this is classic Cascade scenery.

However, instead of the young lavas that bury mostly everything, Yellow Aster Butte is not a volcanic story.

It's 400 million year old metamorphic rock that should be way down deep underneath the Cascade lavas, but it has been lifted and eroded above.

So this is a rare chance for us to see some of the oldest stories in all the Pacific Northwest.

I think we should head over there on foot, take a look at some of that metamorphic gneiss.

(upbeat music) (breeze whooshing) (footsteps crunching) (upbeat music continues) Now, this is a good lookin' rock.

And it's not just this boulder.

There's a whole mountain of this stuff, the Yellow Aster gneiss.

It's metamorphic.

Metamorphic rocks used to be a different kind of rock originally.

It's all these swirls, all these quartz veins.

It's all this high temperature and pressure look was not there originally when this metamorphic rock used to be a sandstone.

The sandstone was not in North America.

It was in Northern Europe.

And the evidence for that is that deep inside of this gneiss are tiny zircon crystals more than 400 million years old.

And the zircons in this Yellow Aster gneiss match beautifully with more 400 million-year-old zircons in Northern Europe.

How in the world are we taking a whole mountain full of this stuff and having it leave one continent and get to us here in North America?

(upbeat music) (breeze whooshing) (upbeat music continues) (footsteps crunching) (upbeat music continues) We're so far back in time that the details of the voyage of the Yellow Aster gneiss will probably never be totally determined.

However, we know the gneiss used to be part of Europe 400 million years ago.

We know the gneiss arrived in North America 100 million years ago.

There is a journey, and it was probably through the old Arctic Ocean squeezing this block of Yellow Aster gneiss between North America and Asia get it parked here in the Pacific Northwest about 100 million years ago.

Wow.

(upbeat music) (footsteps crunching) (upbeat music continues) (gopher chirps) (upbeat music continues) Well, that's an unbelievable geologic story, almost as unbelievable as the scenery here hiking on this sidewalk in the sky and going into the Mount Baker Wilderness area.

This special bedrock is here.

It's protected, and it's waiting for you to enjoy.

(upbeat music continues) - [Announcer] This series was made possible in part with the generous support of Pacific Science Center.