Behind the Scenery Podcast #21 - Favorite Layers of Grand Canyon

Three-Mile Resthouse on Bright Angel Trail.  A lot of funny stories, experiences and emotions are attached to the different rock layers in Grand Canyon.

NPS Photo/M. Quinn

• Favorite Layers of Grand Canyon

  
  

  Never take this place for "granite" again! Geology impacts every part of the human experience of Grand Canyon. People as diverse as the colorful cliffs have discovered secrets in stone. Come listen to their discoveries within layers of Grand Canyon. Are you open to being rocked by the canyon?

  Credit / Author:

  North Rim Interpretation - Grand Canyon National Park

  Date created:

  12/28/2021

  Audio Transcript

  CEILI: So here we are, sitting at the bottom of Grand Canyon surrounded by Vishnu Schist and Zoroaster Granite. And most people when they come to Grand Canyon National Park to visit, they immediately have questions about the geology. Today someone asked me: What's all that green rock? How would you answer that? KATE: Yeah so, that green rock is the Bright Angel Shale layer. Um...The depositional environment for the sediment, when it lays down, it has to be able to form glauconite. So glauconite is the reason that it's green, but what's interesting about that layer for a lot of people is that it's rich with fossils. And when you're hiking across it or moving across it, there's a lot of worm tracks and tunnels and you can find trilobite track fossils out there pretty regularly as well. And when you're actually on that layer and looking at it, there's often a lot of different colors that you can see because of that shallow sea depositional environment that was present. CEILI: What other questions do you get on the trail about geology? KATE: I get a lot of questions about how old things are like, how old is this rock that we're standing on? CEILI: When people ask me that I usually just tell them they're really old. And that some are older than others. Another nice answer is that the newest rocks are on the top and they are 270 million years old. And then the oldest rocks are at the very bottom and they are between 1.8 and 1.6 billion years old. So we've got a whole spectrum here. Kate, can we find any dinosaur fossils here? KATE: The layers here at Grand Canyon predate all of the dinosaurs. So on the very top layer we see some sharks and we found shark tooths and things like that, but a lot of the fossils that we find in Grand Canyon are, um, other marine life. So we have a lot of trilobite fossils. We have shell fossils. We have different plant fossils that we can find in the Canyon, like ferns. And then we also have fossilized tracks of different animals that actually predate what we currently think of reptiles. So Ceili are these the same rocks that We see at ZIon here in Grand Canyon? CEILI: Oh yeah, were you just at Zion National Park? KATE: long pause with an unconvincing “yeah” (both laugh) KATE: sorry, I can't even lie when it makes sense to lie. CEILI: Yeah, most people come, or a lot of people come from Zion to the North Rim. So often people are comparing their experience to their experience at Zion and it's an interesting question to answer because the rocks in Grand Canyon are completely different than the rocks that you see at Zion Canyon at Zion National Park. But the very bottom layer of the Zion Canyon rocks is the very top layer of Grand Canyon’s rocks so Zion is essentially stacked on top of Grand Canyon, and that's because they're all part of the Grand Staircase, kind of geologic formation. So you can even see the full staircase from some parts of the Kaibab Plateau. Yeah, it's hard to remember common questions that people ask about geology, 'cause we've worked in the Canyon for a couple of seasons. And when people are hiking in the Canyon the questions are usually about: Where's the next water station? How do I fix my blisters? How do I hike out of here with success and how might I survive the day? But the cool thing is, all those questions do relate to geology. The geology of Grand Canyon determines every part of a hiker's day down here. Sometimes at the end of a work day at Phantom Ranch some of the Rangers find themselves on the porch eating dinner and sometimes we talk for hours about our favorite rock layers in Grand Canyon. And there's a lot of funny stories and experiences and emotions that are attached to different rock layers in Grand Canyon for different people. (Music) KATE: Inspired by these porch talks, we decided to go around and ask our coworkers and friends what is their favorite geologic layer here at Grand Canyon and why? DOUG: My name is Ranger Doug. I'm a second-year summertime seasonal ranger at the North Rim of Grand Canyon National Park. My job is to meet and greet the public, answer questions, hand out information. KATE: So my question for you is what is your favorite layer here at Grand Canyon? DOUG: Geologic layer? KATE: Geologic layer. DOUG: My favorite is the Coconino, because it's so distinctive. I can point it out to folks at our outdoor visitor centers, prominently seen there. Last night I was out at the veranda behind the North Rim Lodge watching the sunset and somebody asked where the village was and the Bright Angel Trail and you can actually see the offset of the Coconino where the Bright Angel Fault has uplifted the west side and that's kind of a landmark that I look for, for trying to find where the trail goes in and out of the Canyon as well as the, the village area just to the east of where the Coconino’s been off set. So that's my favorite layer. (Music) MATTHEW: My name is Matthew Baldwin. I work in the Backcountry Office out of the Flagstaff Office, and we issue river permits and Backcountry permits and patrol the backcountry. My favorite rock layer here at Grand Canyon is going to be the Coconino Sandstone because when you're hiking out from the bottom of the Canyon means you’re almost home and just those big beautiful white cliffs with the cross bedding and the sandstone. It’s absolutely beautiful. So I lost my hat one time during a blizzard as I was hiking out it got blown off a cliff and it was just gone. So if you’re ever near the South Kaibab Trail and you look over a cliff and happen to see a green hat, its mine, bring it back please. (Music) CEILI: How many miles of under the rim Grand Grand Canyon hiking have you done? Just so we know that like this is really the best and the worst layers. JEN: Overall, or at one time? CEILI: Yeah, just whatever number you have. JEN: It would be impossible to say how many, um, if I had to estimate, it's probably upwards of probably in the 20,000 range. Well, the Esplanade is an easy favorite for so many reasons. It just feels like a different planet really. (Background radio noise “Dispatch, Canyon 20”) You know, like it really I feel like paints an amazing picture of the people who lived here before us because it was a very common layer for them to live in. You know, much like the Tapeats, but yeah, the Esplanade’s got so much history and just so much beauty. And it's really like nothing else in the Canyon. Maybe somewhat comparable to parts of the Supai. You can get some sections of the Supai, particularly at its ends that are very, very similar, but uh, the Esplanade is just amazing to me. It just feels like walking on Mars like just a whole untouched planet. CEILI: And is it like also because it's easy to walk on like is that, is that part of it you think? JEN: Actually, it's really not easy at all. It's actually a lot of switch levels, switch leveling and upping and Downing. And you know one of the challenges of the Esplanade is that you know there's a ton of cryptobiotic soil and can be very difficult to avoid the crypto. Like very difficult, yeah. So it gets very tedious. Now if you don't care about cryptobiotic soil – yes it would be easy walking, but if you're you know, protecting the Canyon as we all do, it's a lot of sidestepping and rerouting and switch leveling and then like you might be going on a level and it gives out and now you have to like scramble up slickrock which can be challenges as well. (Music) MICHAEL: Yeah, my name is Michael Wichman. I'm a backcountry guide for the Wildland Trekking company. I've been doing so for going on 13 years now. Worked for a couple other companies as well, but Wildlands is my primary gig. I often say that this is a difficult place to have favorites in because every layers got their own story to tell with different chapters at each, uh different location that they appear in the Grand Canyon. Uhm, off the top of my head. I typically say the Redwall Limestone's my favorite layer for several reasons, one, it has the most karst like systems in it. The most caves. Limestone is very porous, and water tends to percolate through it and so we get beautiful cave structures. The condors tend to like to roost in those caves. Laying their eggs there with the fledging - fledglings, first flight coming off the huge Redwall Limestone. It can be 1000 feet thick at times in certain places. Also, most of the water features tend to, like the waterfalls and such, tend to occur at the bottom of the Redwall, when the water that seeps through tends to hit the impermeable shale, Bright Angel Shale below it. So I love the Redwall. My other thought as I was talking about this is the...If I get to pick 2. The Chuar formation over up in the Lava Chuar Canyon area, kind of by Unkar Delta further upriver than here. It gets really beautiful. Teals and turquoise like beautiful wavy U-shaped features in it. And it's a more unusual layer that you only see in that area. So I've only ever seen it on a couple few river trips and by foot only twice. Once my partner and I, we hiked from Nankoweap to Phantom off route and that was one of the highlights of that trip. The Redwall for its commonality, or how often you see it, and so every time that we're out here guiding or hiking personally. You're almost always going through the Redwall. And so it's fun to see the different ways that it takes shape and the different members of it. Seeing the coral bed fossils and whatnot inside it. So it's nice to see the Redwall as often as we see it. JESSE: My name is Jesse Barden. I am the North Rim interpretation seasonal supervisor and I've been at the Canyon for like 6 years now. But the ones, the ones that stand out to me the most are the Redwall and the Muav limestone layers. They're kind of stacked right on top of each other, and I think they're just like they, they do the coolest things. They have all the cool caves. They have all the cool slot canyons. The Muav has all the flowing water, not all of the flowing water, but most of the major springs comes out of the Muav. Yeah, they're both just so excellent. A memory of a route through the Redwall. It's called the Red Slide Route, and it's probably the first like really challenging off trail route that I've done in the Canyon and me and my friend Darrin, we're on a river trip, you know, and he and I decided to do this canyoneering route. Down in Western Grand Canyon. And so we climbed up the Red Slide Route to get to the canyon and the route description was only a few sentences. And it said, you know, look for these things. You'll find some hoodoos. It's a little bit scrambly. Made no mention of the 5th class climbing that we'd have to do on the way up, so we started our trip at about 6:00 in the morning. In the dark, it was January, so it was pretty dark for a while. And we made our way slowly up this really steep slope and it's all like crumbly rocks barely held together. Like kind of like Pebble sized it seemed like and so many, many of the points going up the first bit we were on all fours, like using our hands, using our feet. And then we get to the top of this big kind of debris cone, and we're just sort of looking around and looking at each other. Like trying to figure out where the route goes, 'cause we're really just hoping that we don't have to go up the 15 foot vertical cliff that's right in front of us and then Darrin spots a cairn at the top of that Cliff and we’re like ughh, guess we have to go up there. (laughter) And so, yeah, there ended up being three or four of those kinds of like short, fairly easy climbing, but like unprotected and fairly high consequence like cliff bands that we had to navigate with heavy packs and it was a tremendous relief when we finally got through that Redwall section into the Supai where the walking is pretty easy. (Music) JEFF: I'm Jeff Caton and I'm one of the lead interpreters on the North Rim. JESSE: You’re the lead interpreter on the North Rim. JEFF: I am the lead interpreter. Yes, the only one. My favorite geologic layer is the Bright Angel Shale for a couple silly reasons. One reason is I like the way it sounds when it crunches under my boots. A weird, a weird reason, but I like the way it sounds. Another reason is when it was the second time I came to the Grand Canyon backpacking trip that went not terribly wrong, but pretty wrong. I got sick. I ignored everything the Ranger said, like I went out of my way to just check off like and not do what the Ranger said not do. And I woke up and I was sick and this isn't good and I remember the sound of it under my boots. I stopped maybe at Salt Creek, so I stopped somewhere for the hot part of the day. And then about three or four, I started hiking again. There were a few clouds, and I promptly started throwing up so I remember that the sound of the Bright Angel under my boots. And kneeling on it to puke several times. (Music) ELYSSA: My name is Elyssa Shalla and I'm a Park Ranger here at Grand Canyon. My favorite geologic layer is by far the Tapeats Sandstone. I think it, just being able to look at and touch and see all of those sediments in that layer gives you the opportunity to really kind of transform yourself back in time and think about all the different ancient landscapes that the Canyon has been through throughout its lifespan. When I think of the Tapeats, I think of all of the years that I worked down at Indian Garden as a Ranger and all of the times we went down into the Tapeats Narrows. You know getting to talk with people, people that were just excited to be down there. Some people that were struggling to get through that section and up to the Indian Garden campground. I think it's, it's packed with beauty and suffering. (Music) KATE: Behind the Scenery is brought to you by the interpretation team at Grand Canyon National Park. We gratefully acknowledge the Native peoples on whose ancestral homelands we gather, as well as the diverse and vibrant Native communities who make their home here today.

Behind the Scenery Podcast

Hidden forces shape our ideas, beliefs, and experiences of Grand Canyon. Join us, as we uncover the stories between the canyon’s colorful walls. Probe the depths, and add your voice for what happens next at Grand Canyon!

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