Transcript

This is the Connection. A dirty free hub podcast connecting gravel cyclists to where they ride through short stories about culture, history, people, places in lands.

Kira Corbett – Dirty Freehub

I’m Kira Corbett, and today on the “Dirty Freehub” podcast, we have Dr. Kim Eli, also known as The Rock Doctor here at Dirty Freehub. Dr. Kim Eli earned her PhD in geology by investigating the evolution of volcanic arcs in the Timor-Leste north of Australia. She now works in the field of plant ecology, studying tropical and arctic ecosystems with a focus on data management

All right. So Rock Doc, it’s a pleasure to have you today. Thanks for having me, Kira

Dr. Kim Ely

Yeah, of course. Can you tell me a little bit about Wolf Rock and why it’s such a feature of this landscape?

So Wolf Rock is located on the western side of the Cascade Ranges in Oregon in the Willamette National Forest. [00:01:00] It’s about four and a half thousand feet high, so it’s not a high peak, but what makes it stand out is its steep sides with 700 feet sheer drops from the top down to the surrounding forest.

And this cliff face notably includes a prominent arch, which is about 70 feet high, from where a giant slab broke away from the cliff The southwest side of Wolf Rock drains into the headwaters of the Blue River, which is a tributary to the Mackenzie River. And geologically speaking, Wolf Rock is the eroded core of an old volcano and is made of andesite, which is a very hard, erosion-resistant volcanic rock type.

And it seems that Wolf Rock is not named after a Mr. Wolf, but from its shape, which from some angles look like the head of a howling wolf.

Kira Corbett – Dirty Freehub

Yeah, I’ve seen it at times. Sometimes I thought it almost looked like a tooth, like a shark tooth So I heard it’s the largest monolith in Oregon. What exactly does that mean?

Dr. Kim Ely

So I’ve been told that in the movie “Space Odyssey 2001,” a monolith is an alien artifact. However, [00:02:00] when used as a geological term, a monolith is a name for a rock formation that is composed of a single block of rock that has been exposed by erosion. The key here that it’s, is that it’s a single rock unit and not a stack of layers or a sequence of units.

So other examples of monoliths in Oregon are Haystack Rock in Cannon Beach, which is about 235 feet high, and Stein’s Pillar near Prineville, which is about 350 feet tall. So Wolf Rock wins the largest monolith in Oregon really easily. Elsewhere in the US, other famous examples of monoliths include El Capitan in Yosemite and the Devils Tower in Wyoming.

So Uluru in Central Australia is such an iconic feature of that Australian landscape. It rises to over 1,100 feet above a flat sand plain covered in spinifex grass. It’s famously known for appearing to change in color, particularly at sunset. And Uluru has great cultural significance for the Anangu people, and it’s a sacred site that features in many [00:03:00] traditional Dreamtime stories, so it’s a verily special place to visit

You can drive up to it. You can walk around it. It’s very popular place to visit. Walking around it does take quite a few hours though

Kira Corbett – Dirty Freehub

Are there any legends or myths around Wolf Rock? Anything happen to be with wolves?

Dr. Kim Ely

Not that I could find out. If there are secrets that Wolf Rock is keeping to itself, or at least hasn’t let onto the internet. But Wolf Rock is located in the traditional lands of a number of tribes, including the Confederated Tribes of the Siletz Indians, Confederated Tribes of the Grand Ronde, Cayuse, Umatilla, Walla, and Molalla people.

However, I was unable to find any stories about this geological prominence. Given the elevation and the rugged terrain, it’s likely this was an area that was probably only visited by people on a seasonal basis and was not a site of permanent habitation.

Kira Corbett – Dirty Freehub

It seems like Wolf Rock is relatively unknown. Do you know why that might be? Yeah, I suppose, [00:04:00] unlike Oregon’s most famous monolith, which is Haystack Rock, Wolf Rock is not an easily accessible roadside tourist attraction. It’s about nine miles of forest roads once you leave Highway 126 to get anywhere near the base, and there are no established hiking trails on the mountain.

Dr. Kim Ely

There’s no signs, and there’s no trailhead with facilities, so you really have to know it’s there to explore its secrets. It is a rock climbing destination though, for people who like to go off the beaten path. There are 37 documented climbing routes. They’re mostly classified as quite challenging grades, around 5.10, and the routes feature up to 900 feet of that vertical cliff face.

The easiest way to the top is a class three scramble, so climbing it is definitely not for everyone. But a good way to get a view is to take a one-mile hiking trail up nearby Carpenter Mountain

Kira Corbett – Dirty Freehub

You mentioned that it is eroded and the eroded core of an old volcano. So how old is it and how can we estimate its approximate age?

Dr. Kim Ely

So there are two main techniques that geologists use to [00:05:00] work out how old things are. One is using the abundance of certain elemental isotopes in minerals to calc-calculate what we call an absolute age. You might have heard of carbon dating or uranium-lead dating. And another approach is to look for clues in the landscape, often based around the characteristics of the feature or the relationships between features.

This is where we start to get some clues about how old Wolf Rock is. So the first clue is the texture and features of the exposed rock surface. Wolf Rock will be smoothed by erosion, the high sheer cliffs are a feature. This really contrasts with the characteristics of young volcanoes in this region.

Think about the chaotic, jagged rubble of the twelve hundred-year-old basalt on the Mackenzie Pass, or really recently erupted lavas on Hawaii. Or think about it in comparison to the loose, crumbly sides of Lava Butte or other cinder cones Another clue is the position of Wolf Rock in the current landscape.

So the peaks of the High Cascades form a [00:06:00] fairly straight line of young volcanoes that stretch across Oregon. But Wolf Rock lies 20 miles west of Belknap Crater and Mount Washington, and this position off the line of the High Cascades suggests that these features are not closely related. So Wolf Rock is older than those modern Cascade Mountains

Yeah, that’s just so fascinating that it’s not known, but it has so much to it So the Western Cascade volcanoes were really explosive, producing a lot of the ash that was blown east into John Day Basin 100 miles away. Around 40 million years ago, the climate in Central Oregon was tropical, and fossils preserved in volcanic ash and mudflows tell us about the plants and animals, including large tortoises, crocodiles, large cat-like creatures, and tiny horses about two feet high that lived in forests.

Then around 35 million years ago, the climate cooled and the landscape transitioned into more grasslands. But for the volcanoes of the Western Cascades, the big change was [00:07:00] tectonic, not climatic. Around six million years ago, the motion of the subducting Pacific Plate changed, which shut off the magma source of the Western Cascades and resulted in the beginnings of a new range further east, which we now know as the High Cascades.

At that point, eruptions ended in the Western Cascades, and the landscape has since been shaped by erosion, by periods of glacial activity and lots of rain. what remains of the towering volcanic giants are now their resistant cores, such as Wolf Rock

Yeah, the Cascade Range is a complicated story. All of Oregon is really, geologically speaking. A lot has happened in the last 100 million years

Yeah. Well, Thank you. And is there anything else you’d like to add? No, go for the ride. Check it out. See if you can get a good viewpoint

Thanks, Kim

Thanks.