Have you been to Friday Harbor before?

Taken the ferry out to San Juan Island?

That's where we are today.

There's dozens of islands in Puget Sound.

Many of them with a glacial story.

A bunch of glacial deposits making up the island.

But here on San Juan, it's bedrock.

The bedrock is so old and so exotic and so complicated, that there's actually three different kinds of bedrock on the same island.

The source of those locations, the bottom of the Pacific Ocean, an island in the Pacific Ocean, and even an island in the Arctic Ocean.

Bedrock Island, three stories.

Here's the first.

An ocean floor story 150 million years old.

Look at this dramatic, complicated, contorted, cracked up bedrock.

Specifically here, this is radiolarian chert from the ocean floor itself.

Heavily fractured.

Lots of quartz veins coming through.

But the dark look here is getting in the way of seeing the original rock.

It was originally arkosic sandstone 150 million years old, out in the middle of the Pacific Ocean near an ocean island somewhere.

And this collection of rocks here locally, the Constitution formation is telling that story.

But the wild thing is, these rocks have been correlated to the mountains, and Mount Shuksan with beautiful greenschist, and the Easton, Washington area with green phyllite.

Those are also part of this ocean floor story.

So the San Juan Islands can be connected geologically to select spots within the high Cascade Peaks, including Mount Shuksan itself.

This side of the island has different bedrock.

It's the same island, but here we have granite.

Beautiful salt and pepper, coarse grained granite, diorite, even dark colored gabbro.

These are plutonic igneous rocks that once fed a volcano in the middle of some sort of ocean.

Which ocean?

This is the Arctic story.

These are granites from below the floor of the Arctic Ocean north of Europe.

And here's a little piece of the Arctic Ocean floor itself that didn't get melted by the granite.

These guys have been dated between 400 and 500 million years old.

These are some of the oldest rocks in all of Washington.

And these rocks can also be projected to the east, up into the North Cascades and up there the Chilliwack terrane, the Chilliwack group, the Yellow Aster gneiss, which is part of actual Northern Europe continental crust, can be tied to these rocks which were offshore in the Arctic.

Turtleback exotic terrane.

Another portion of San Juan Island itself.

More exotic bedrock on this side of the island.

This is still San Juan Island.

Now we have dark lava and incredibly beautiful blocks of limestone.

Now, limestone is rare for Washington.

And yet this is pure limestone.

Let me prove it to you.

Take some hydrochloric acid.

A nice piece of this limestone.

Oh, yeah.

Effervescing, fizzing like crazy.

The HCl and the calcium carbonate in the limestone.

So the limestone blocks are embedded beautifully in this basaltic lava.

I've never seen anything like this.

And the interpretation is that this is basaltic lava that erupted underwater out in the middle of the Pacific Ocean with an oceanic island and the limestone are former coral reefs that ringed this island and pieces of the coral reef broke free and tumbled down the slope in the submarine scene, with these lavas forming pillows as they go out into the water.

That dynamic underwater drama is preserved perfectly in this scene.

The limestone blocks in the basalt.

The kicker?

We're not in the middle of the Pacific Ocean anymore.

That former Hawaiian island has now been added to North America.

Listen, with hundreds of millions of years of time, there's plenty we do not know about these three exotic, bedrock stories.

But what we do know is that the Arctic and the Pacific pieces of bedrock got together, got soldered together 100 million years ago, at some point along the western margin of North America.

And that was journey one.

Journey two is clearly moving pieces of bedrock like we have here north along the western margin of North America.

Maybe California to Washington, maybe Mexico to Washington.

Maybe it's stuff that was in Washington now up in Alaska.

That's all possible.

And further research is being done now on these exotic terrane bedrock units like here on San Juan Island.