Dr. Win McLaughlin, a geology professor at Southwestern Oregon Community College, provides us with a deep understanding of the geology, history, and ecology of the Oregon coast. The Oregon coast is filled with unique geology which is characterized by its young age and the presence of sand dunes formed during the ice ages. She describes how the sand dunes are formed, ecosystems within and nearby, potential impacts of climate on the dunes, and the salty terrain to consider as a cyclist! She also talks about the Whisky Run mountain bike area.
Transcript
Dirty Freehub
This is The Connection, a Dirty Freehub podcast connecting gravel cyclists to where they ride through short stories about culture, history, people, places, and lands.
Dr. Win McLaughlin – Geologist and Paleontologist
I sort of joke that you end up paleontology because you can’t decide what you want to do. I get to do biology and geology and I preach the church of sand.
Dirty Freehub
I love that. Hi, everyone, and welcome to the Dirty Freehub Connection. It’s Kira Corbett, and today I’m excited to preach to the Church of Sand, exploring the topic of the Oregon sand dunes with our guests today, Dr. Win McLaughlin. Dr. Win McLaughlin has her doctorate in geology with a background in paleontology. She’s currently a geology professor at Southwestern Oregon Community College. I guess we’ll just kick it off. So thanks so much for joining us today. I’m so excited to talk about dunes. I imagine they’re not anything like maybe like some of those popular movies out there with dune. But how did these how did these actual sand dunes form? And like, what is the geology behind the dunes?
Dr. Win McLaughlin – Geologist and Paleontologist
So the geology of the Oregon coast is pretty weird. Basically, compared to I mean, almost anywhere else in the world. Oregon coast is really young. So most of all of the state of Oregon is basically things like Hawaii and all the sediments around Hawaii that came into a subduction zone and got scraped off on the side of North America. So the actual boundary to the continent of North America, or what it originally was, is practically on the Idaho border. And so what that means is that instead of having kind of a solid block of rock effectively under us, we have all of these bits and pieces that are sort of scraped off on the side. I make everything cooking analogies in my classes. And if you think of oceanic crust like a brownie, it’s really thin. It’s very dense. Continental crust is more like angel food cake. It’s not very dense. It’s really thick. And so if you slide them together, basically Oregon is like bits of brownie and the frosting and whatever getting scraped off on the side of the cake. So that really complicated, messy, broken, fractured start is also a big part of then why we get sand. So sand is what’s left after you’ve broken and fractured rock into small pieces and then moved it around with usually starting out water. And then sand dunes are what’s left when only the wind can transport it. And if you think of like scooping up a bunch of gravel and mud and all sorts of different things and blowing on it, only the smallest pieces are going to actually move with wind. So if you pick up a handful of sand on a sand dune, it’s going to be really, really uniform, really tiny pieces. And most sand dunes are light colored because it’s only the strongest minerals that are left. So they’re mostly quartz. Part of what’s also kind of interesting, I guess, to add in with the geology, like history of the area, is a lot of these dunes, they’re still active, they’re still forming today, but they came from the ice ages. So if we average temperature and precipitation over the whole planet, the colder it is, the less precipitation you have, the warmer it is, more precipitation. So during the ice ages, you have a lot less precipitation, it’s very, very dry, even though it’s cold. And so most of these dunes on our Oregon coast likely started forming in the ice ages, and were more extensive. So a lot of places that have trees today It’s not that they were logged old growth forests or whatever, they just weren’t forests. They’re trees that have kind of come in as it’s warmed, the ice ages retreated. I live in this totally forested area and you dig any hole on property I live on and it’s sand. It’s ice age sand dunes. And so what’s cool as a like half geologist, half paleontologist for that is we actually get fossils out of the dunes here. University of Oregon, like introductory geology field trip that was just south of Florence. Great place to see the dunes. Lots of and one of the undergrad students was like, what’s this big bone that I found? And it was actually a walrus arm bone. So we had boleruses in Oregon, not that long ago.
Dirty Freehub
Wow, that’s amazing. What kinds of things are living in the dunes? I mean, it’s kind of an interesting like ecosystem or something.
Dr. Win McLaughlin – Geologist and Paleontologist
Yeah, I mean, because it’s so dynamic and changing, you get really very different native and invasive plant and animal communities. So a lot of the like dune grasses, the beach grasses we see here are unfortunately invasive. So there’s stuff that was either accidentally or often intentionally introduced from mostly Europe and North Africa. And the idea behind a lot of those was that they wanted to stabilize the dunes. They wanted them to not move and stay in place, but that has its own problems. I mean, this is a system that’s supposed to be constantly moving sand from sort of one place to another, and you end up with places like, again, Cannon Beach, where the sands moving off of it much faster than, you know, the city conquer, you know, governments would like since that’s all of the tourism is going to the beach. But there are native dune grasses and those are really important because it provides a little bit of shelter for a lot of different birds that nest there. And our big controversial one for a lot of the Oregon dunes are snowy plovers. So these are like little tiny you know, sandpiper relative birds. Killdeers are also plovers that we have all over the country. And the snowy plovers will only nest in kind of areas with sort of native grasses with somewhat moving dunes. And so they close big areas of the dunes during nesting season because if they leave their nests, sometimes they won’t come back and they’re quite endangered. So they’re very controversial because on one hand, it’s neat. We have this population of these endangered, ecologically important birds, but it also results in you can’t always go play on the dunes when you want to. It’s kind of the same question as with the dunes and that if you approach this from an environmental perspective, what are we trying to restore to or what purpose are you trying to do with ecological restoration or environmental protections? realistically, we’re never getting back to what it was before there were people here. And even then, it’s a very common sort of misconception that everything was just totally peace with nature before white people got here. These are landscapes that were very heavily managed by indigenous people for thousands of years. They used controlled burning. They used even certain types of dredging. So out here on the coast, a lot of the mouths of rivers were very intentionally controlled. And some of the same sort of processes that we do today on smaller scales of building jetties, building a structure called a groin that helps trap where sand moves. And even on some of the roads here, you’ll see sort of barriers set up. A lot of times that’s for sand dunes moving. I mean, it sort of depends on what you’re trying to help. There’s there’s things that live in the dunes that aren’t found anywhere else. And one of the big factors is, you know, back to the pile of gravel or sand or whatever in your hand and blowing on it. The wind is only moving these really smallest pieces, but the smaller the piece, the less energy it takes to move it. So your clay sized little, little tiny, tiny grains of rocks are getting blown out of even the sand dunes. And that’s actually a really important source for nutrients for soils. So a lot of our main agricultural areas, part of why they’re so fertile is during periods like the ice ages, when it was much drier and you had a lot more sand dunes in different places, those dunes are doing a process we call winnowing. where the larger materials left behind, the sort of small sand grains get moved along, but all the dust gets blown much farther inland usually. So places like the Willamette Valley, the Central Valley of California, a lot of eastern Oregon and eastern Washington, those soils have huge contributions from windblown dust.
Dirty Freehub
You talked a little bit about how they changed. Is there any insight to how the dunes could change in the future? I’m thinking some common water areas that have now dried up. Is there any kind of future research on the dunes? Not enough.
Dr. Win McLaughlin – Geologist and Paleontologist
That’s sort of probably the story with everything. But it’s really definitely something that will be impacted by changes in climate. So we’re seeing a lot hotter and drier summers. And that’s going to change how the dunes move around. So If you have more precipitation, even just the kind of marine fog layer that we get, like all of July was just totally warm and sunny here, whereas now that it’s August, it’s like overcast most mornings because the fog rolls in at night. And that fog leaves just enough moisture on the dune that you kind of get a little like crust in the sand. And that helps prevent a lot of it from moving in the wind. But if you’re having drier days and more time that you’re not doing that, also combined with sort of human use. So if we go out and ride ATVs or bikes or hike on these dunes, you’re breaking through that little crust. And that kind of crust keeps everything in place once we’ve destroyed that, which, you know, again, it can form really quickly again, but that’s more material that’s getting blown by the wind. the bigger material is, you know, maybe ending up on the roads, maybe the dunes are just sort of migrating out of where we planned on them being, but that’s also changing that amount of even things like air pollution.
Dirty Freehub
Where’s a good place to see the dunes? And you even just briefly mentioned like that maybe even riding and participating on interacting with the dunes could be harmful too. But so where’s a good place to interact with them and to see them from afar?
Dr. Win McLaughlin – Geologist and Paleontologist
One that I really like that kind of gets a little bit of everything and has a little bit of dunes it has and pine forests and everything. This is the South Slough Nature Reserve and they have a really cool educational outreach. They have a lot of different programs that go on there. South of us there’s a little bit of dunes mixed with a bit of everything else that’s the Whiskey Run bike area. Whiskey Run is a like previous ocean level that it’s named for that like flat layer that used to be a beach and it’s 80,000 years old. So it’s from the middle of the ice ages. The name comes from the fact that in Prohibition, it has a bunch of sea caves below it and they were smuggler sites. So people smuggling bootleg alcohol would come in at high tide and stash whiskey barrels in these sea caves and then come back at night and pick them up to like ferry them from basically San Francisco up to like Portland and Seattle. There’s all sorts of trail systems and ATV areas. I mean, the whole Oregon coast is really got a lot of economy set up around that. And, you know, again, it’s a resource that’s there and handles use pretty well, but definitely there’s sort of a time and a place. And I think one of the big things is that I do see people off trail where they really shouldn’t be and that can be causing a lot of harm. But it sort of gets back to this question of that it’s not that simple. It’s really complicated. So there’s a place in between Lakeside and Coos Bay that is a very popular ATV riding area. People also do like fat bike riding out there and everything. And folks have complained because right from 101, you can see all these trails down these big dunes. where people go, and then it’s got the grasses in between them. And they’re complaining about, you know, look, the plants are all getting destroyed. Well, again, those are invasive plants. So is it bad that they’re getting destroyed? I’d argue in that case, it’s probably good for the dunes, the dunes should be a little more free to move and able to move and It’s messy and complicated is the short answer on it.
Dirty Freehub
Trying to think, is there anything else that you’d want to make aware to gravel cyclists or people visiting or just anything to add in general?
Dr. Win McLaughlin – Geologist and Paleontologist
I think another part too for thinking about bringing in the bike part is salt. It’s one of the things that makes this a little bit different than if you go see sand dunes in Utah or Arizona or even parts of California, Nevada, is that we also have the salt spray. So this is another thing that changes how the dunes move and can be one of the things of like why staying in designated areas or staying on trails can be important is we have not only that moisture sort of crust that forms, but also actually salt. So a lot of the crust that forms that keeps the sand kind of relatively in place is salt spray. So it’ll come even a mile inland, you’ll still get enough salt that’s from the waves splashing, you get little droplets that get aerosolized, they float in and in the fog. And then you’re quite literally precipitating out salt on top. Yeah.
Dirty Freehub
Yeah, we have the exact opposite problem over here. It’s so dry and like nothing rotates or anything. But oh, wow, this was really fascinating.
Dr. Win McLaughlin – Geologist and Paleontologist
Happy to answer any other questions.
Dirty Freehub
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