TRBTC Episode 13 Red Rock Canyon Notes and Transcript

 Sources

Very special shout out to Miles Todzo and Devinne Cullinane who helped edit the episode transcript.

https://www.blm.gov/sites/blm.gov/files/uploads/Nevada-Red%20Rock%20Canyon-Geology.pdf - intro information

https://www.mountainproject.com/area/105731932/red-rocks - info on rock climbing

https://www.lvwash.org/about-the-wash/hydrology-geology-biology/index.html#:~:text=The%20entire%20hydrographic%20basin%20is,then%20flow%20into%20Lake%20Mead. - las vegas wash 

https://www.nps.gov/articles/desertvarnish.htm - desert varnish

https://www.mountainproject.com/route/106056281/the-pearl - the pearl V5

https://www.mountainproject.com/route/113802237/the-wave - The wave V3

https://www.mountainproject.com/photo/106267165 - cannibal crag

https://smallpond.ca/jim/sand/overview/ - sand dune to sandstone formation animation (Definitely check this one out)

Referenced photos from the episode (and captions that give a little more context)

The cliffs of Red Rock Canyon seen from Las Vegas. The flat desert plain in the foreground is part of the Las Vegas Basin which was formed when red rock pulled apart from the Valley of Fire.

My brother and I climbing the Plumbers Crack Boulder. If you look close you can see linear bedding planes that are oriented in the same direction as the perfect split. Miraculously this boulder landed so that it could split down the middle. Also, the desert patina coats the outside of the boulder, which contributes to a much harder face climb.

The potato chips boulder (V2) which features an imperfect split along one of the bedding planes to create many little ridges and holds on the split face. The best holds for me were the ones coated in the desert patina. The photo features my brother utilizing some of the bedding planes to top it out.

The canibal crag sport climbing area: This is a perfect display of the various migrading sand dunes that hardened on top of one another. The big horizontal breaks in the rock are the separations between different subsequent sand dunes. THe smaller laminations are the cross beds that were deposited as the sand dune migrated. The more angled cross beds show a period with larger sand dunes. The chalked up route up the prow of the crag uses holds in the cross beds. See the source labeled “Sand dune to sandstone formation” for more information on this process.

Me climbing The Wave (V3). Other than featuring a giant cutout in the rock, this climb also features little iron nodules in the sandstone that proved to be nie little holds.

A close up display of the tightly banded vibrant display of color in the rock. The varying degrees of red and orange have to do with the iron minerals in that sand dune. Since it was raining on this particular day, we did not climb. My hand is just there for scale (and not reaching to grab a hold!!)

TRBTC: Red Rock Canyon - Transcript

This is the Rock Behind the Climb, the podcast about the geology of different rock climbing spots. I am your host Quinn “The Jazzhammer” Todzo, and this episode will make you see every single climb differently in Red Rock Canyon, so get ready to get friggen blitzed, geologically. For those who are new or haven’t heard this podcast in a while, my goal is to really connect the features in the rock that define the climbing in an area to the geologic processes that created them.

In this episode we are going to explore why exactly the redder the rock provides better holds. We’ll talk about how winds changing direction millions of years ago causes you to shift your weight halfway up a sport climb. Bouldering wise I’ll get into the main reason is that everyone from your V0 homies to your V10 crushers come back from red rock psyched out of their minds. And finally I’ll close with why the city of Las Vegas specifically ended up right next to this natural playground.

Red rock canyon in Las Vegas is hands down the best all around rock climbing spot in America. You’ve got long monstrous trad routes right next to amazing sport climbs and absolutely world class boulders. There are so many problems and routes of all types and difficulties right next to each other. And better yet, you are literally less than 30 minutes away from Las Vegas. You can literally send, rage, lose all your money, and crush again all in the same 24 hour period.

Coming in from Las Vegas, the approach into red rock is a spectacular change in environment. You go from this insanely artificial metropolitan area with strip malls and casinos to this giant red and white striped cliff that abruptly emerges from the flat desert plain, buttressing the western horizon. It’s crazy because the giant cliffs and deep canyons make it feel wild, remote, and adventurous even though a glance to the east reminds you that you are not too far from civilization (or maybe the fall of civilization in the case of some casinos).

So, let’s start off with the basics: what kind of rock are we climbing, and where did it come from?

The rock at red rock is Sandstone which means that it was formed from a bunch of sand grains clumping together over millions of years to eventually form the stone that we see today. In the case of red rock canyon, the sand was deposited by wind blowing the sand grains into giant sand dunes. Over time, these giant dunes got buried by more wind blown sand dunes to eventually get pressed into rock in a process called lithification. 

When you climb the rock today, you can actually see evidence of the sand dunes by the way that the rock is cracked and striped. Often, you will be able to pick out large horizontal cracks in the rock. These are known as beds and they mark the separation between subsequent sand dunes. In between those beds are thinner sloped stripes of rock called cross-beds. These are deposits that mark the travel of a sand dune over time. Because yes, sand dunes move over time! To learn more about this, I have included a resource in the show notes that has cool animations that describe this process.

A good example of what this looks like is at the Cannibal Crag. Climbs on this rock feature holds on the cross beds and spots to rest in between beds. What’s cool is that you can see how the environment changed over time as you climb up the rock. For instance, you could be climbing up a section of rock where all the cross beds are sloping down from left to right, and then abruptly the beds will shift to sloping from right to left. This is because the wind would have changed direction with the next sand dune! After years of generally blowing from left to right, something drastic about the land changed to alter the wild patterns. All of this to make you have to shift your weight to account for the cross beds sloping now right to left. 

The thickness and steepness of the bedding planes is controlled by the relative wind speed at the time that the sand dune was formed. Thicker sections with more steeply slanted cross beds show a period with larger sand dunes and therefore stronger wind speeds. Flatter holds are of times when the wind wasn’t blowing as strongly. So if you are climbing along on steeply inclined cross beds without a rest in sight, you can blame the high winds at that time for making such a massive sand dune!

If you have never been to Red Rock, I have put a photo of what these beds look like in the show notes. You know that Dr. Seuss book Oh the Places You’ll go where the little dude walks through a world that has a bunch of multicolored striped hills. It kind of looks like that, but just varying degrees of red, orange, and white. I dunna know. Either way it’s vibrant as heck.

The red and orange colors come from the iron minerals that are mixed in with the sand grains that rusted over time. 

The iron in the rock actually does more for it than just provide cool colors. The sandstone layers with the iron minerals actually give the rock layer a lower permeability. This means that less water can get in between the grains and cause it to deteriorate. This is why the redder the rock, the more weather resistant it is, and therefore better holds.

On a lot of climbs, the best holds are the ones that are darker colors, because they have resisted weathering better than the less metallic rock layers. This allows the redder sections to develop into larger jugs and deeper crimps than the lighter colored holds which are typically slopier and smaller.

Also, just as an FYI, the rock as a whole is porous, meaning that even though it looks strong and compact, water can actually percolate through it. When water is trapped in the rock, it makes the rock weak and easily breakable. So definitely don’t climb on it for a few days after it rains, because you would be likely to break a hold.

OK so to recap this section I thought I would share a few slightly altered song lyrics from a modern poet of our time by the name of Taylor Swift that I think captures the essence of the sandstone at red rock. Ok here goes

I am a sand dune, it's a typical epoch night

I'm carrying the kind of minerals she doesn't like

She'll never know your climbing style like I do

But she wears calcite 

I am oxidized

She's light colored, and I'm a little rusty

Dreaming about the day when you wake up and find

The hold you're looking for has been red the whole time

Not sure if that made sense, but alas: we’re moving on

If you are impatient like me, rather than dive straight into the cliffs and crags that scrape the western skyline when you drive up from Vegas, you’ll actually take an abrupt right turn to go hit up the Kraft Boulders which you can access before actually entering the national conservation area. 

The bouldering here is truly la creme de la creme. It’s incredible. Basically every boulder I’ve tried in the Kraft area felt like a gym problem. So many boulders have amazing holds, mostly decent landings, and offer a wide assortment of problem types from crimpy slabs to muscully overhangs. What makes this spot truly remarkable to me is that you have hundreds of problems in such a dense area that completely vary in difficulty. This is really cool because no matter who you are or where you are in your bouldering journey, you can find a ton of really fun problems in the Kraft mountain area.

When you get to the Kraft bouldering area it can feel like a maze just looking around for the exact problem I wanted to try. But if you happen to look up just past the endless field of boulders, you’ll notice Kraft Mountain, which is where the boulders actually originated. 

Basically, the giant field of boulders is a result of giant blocks of rock tumbling down the mountain from this one lens of intact sandstone due to erosion. Over time, as water and ice entered the cracks and joints within the sandstone unit, the blocks fell and tumbled down the mountain. This is known as a talus field, which are geological features found in a lot of mountainous areas where rockfall is common.

Some of the most well known and popular bouldering areas in America were formed in a similar fashion. Places like Joes Valley in Utah, Icicle Creek in Washington, and even Yosemite Valley are places with bouldering formed from talus field.

In talus fields, I would argue that the factor that influences the climbing the most is the orientation of each boulder after coming to rest, which is dictated by rockfall. Rockfall in Kraft mountain has occurred after years of water freezing and thawing in the cracks of Kraft Mountain. However, at different times and under varying circumstances each boulder detached from the cliff, rolled for a bit, and found its resting place.

The orientation of the boulder as well as its size, are both dictated by the rock fall. This can mean the difference between whether you have a low angle slab climb or an overhanging test piece. There are boulders with huge airy top outs like after a bunch of crimpy moves like The Pearl V5. And then, there are 5 foot boulders, featuring 7 moves to get out of a mini cave and over the lip to the top out like The Wave V3. And the crazy part is that these two completely different problems with different styles are right next to each other. 

A prime example of an iconic red rock boulder is one known as the cube. The boulder is this massive, nearly perfect rectangular block of sandstone that somehow landed perfectly on its side after tumbling down the mountain. The fact that the block a) stayed intact during the rockfall event, and b) landed on its side allows for some sick high ball faces and striking arete problems. The actual rock climbing holds probably have more to do with erosional processes after the cube had fallen into place, but the essence of the climbing style is because of the rock fall.

Another boulder that had an interesting rock fall is the one known as the Plummers crack. THis is a freaking beast. It’s one of those problems where the photos really don’t do it justice. Basically it’s a 30 foot rock that is split in half down the middle, creating a chimney style crack that gets wider as you get higher up. It’s not technically that hard, but its one of those things that is incredibly scary but also so cool and rewarding when you top it out. 

Anyway, the instance of this boulder in the context of rockfall is quite cool because the boulder literally split in half. What must have happened is that when the plumbers crack boulder came tumbling down, it landed with so much force that it literally split down the middle. That doesn’t explain the whole deal though, because how could you possibly get a crack so perfectly sliced where each face inside the chimney is nearly smooth. Most likely there was already a planar joint in the rock formed during it’s original deposition. That means that the rock had to have this coincidence of landing in such a way that the natural joint plane was perpendicular to the ground, with enough force to split the entire thing! 

Next time you are out at red rocks or any boulder field, I encourage you to look at the boulder’s with the question of how did the boulders end up there, and then look around at the environment and see if you can find any clues from the surrounding area or adjacent rocks to piece together what might have happened. 

Then, when you make your grand discovery and inevitably annoy the crap out of your friends by talking their ear off while they are just trying to send their project, you should reach out to me. I would love to hear about your mind-blowing geologic discovery while out climbing! My contact info is in the show notes

Aside from the orientation of the boulders, I should also mention the main reason the boulders have so many holds. It has to do with this stuff called desert patina. It’s these dark patches of metallic minerals that coat the outside of the rock. The patina, just like the redder sand dune layers, protects the rock and makes it a lot less prone to erosion. In many cases the rock erodes around the patina, which makes for good cracks and edges to pull on . I saw a ton of cool climbs where you have to suffer through a number of tiny little crimps before lunging for a giant patina jug. The patina was especially helpful for me on the climb known as Potato Chips V2, which is an overhanging climb where you are relying on small holds that you can’t really evaluate by just looking at it. My strategy of going for the patina holds proved successful because they had a little more to grab onto than the non patina crimps.

The patina is featured prominently throughout the park. For example, basically the entire black velvet wall is just the sandstone coated in the patina. In many cases, the patina functions in conjunction with the sand dune beds and other water features to create crazy holds and climbs.

OK ok ok, so we have this cool striped rock made from sand dunes, and bouldering that is absolutely world class, but there is one very important aspect about red rock that elevates it to one of the best crags in America. 

It’s that if you are out having an adventure up in the canyon and get caught in an insane hail storm, you aren’t likely 8 hours away from the car and have to have a cold and wet trudge back to the car before you have to drive another hour plus just to get a hot meal.

No, Red Rock Canyon is this amazingly wild feeling location that is just a stones throw from Las Vegas. Like I said in the intro, you can literally wake up after a crazy night out in Vegas and within 20/30 minutes be fighting off that hangover with a 13 pitch trad adventure.

I think you are pretty hard pressed to find many other situations like this where there is a major metropolitan area so close to this quality of a climbing crag. But, Las Vegas is an interesting situation. The city is located on a completely flat desert plain that is nestled between mountain ranges. 

The geologic term for this is a basin and range topography, which is to say it is a part of alternating sets of mountains and flat lands due to the earth’s crust extending. Over the course of hundreds of millions of years, the North American plate got compressed which gave rise to a bunch of mountains. And then, kind of like when you release a slinky, North America extended back outward. Essentially, the mountain ranges around Las Vegas were all clumped together, but then the Earth’s crust extended, thus separating the mountain ranges. This created huge valleys that got filled in with sediment over time like present day Las Vegas.

If you ever take a day off of climbing and visit the valley of fire state park which is just east of Las Vegas, you’ll find sandstone that very closely resembles red rock canyon. This is because the two parks literally split off from one another leaving Las Vegas in the middle.

A key feature of the Basin and Range topography is that it makes the mountain ranges quite steep and shear, leaving you with a very flat basin right next to incredibly steep cliffs. This makes for the unique situation of red rock canyon and Las Vegas because the flat basin is perfect for building a city upon, and the steep shear rock makes the rock climbing possible.

Well, that’s about all that I have for you. I think there’s a lot more I could talk about with Red Rock canyon and the rock around Las Vegas, but I will cut myself off there for now. If there is anything I want you to take away from this episode though, it’s that all the rocks in Red Rock Canyon have a unique story of how they got there. Whether its massive ancient sand dunes that gave way to the crazy striations in the rock, or the boulders that all fell out of Kraft Mountain and landed in precarious positions to allow for so many different boulder styles, or just taking a step back and looking at the Red Rock as one half of this mountain range that ripped apart leaving fabulous las vegas in the middle. In the words of T Swift: What you’re looking for has been in here the whole time!

Thank you so much for listening. If you have any further questions, have an idea for a place I should visit, or just want to connect with me, shoot me an email. All my info is in the notes. I have also included a link to my blog which includes photos and a transcript of the episode. All right, catch ya on the next one! Jazzhammer Out!

Episode 12 The Grotto Transcript, Photos, and Sources

Episode Link:

https://soundcloud.com/quinn-todzo/trbtc-ep12-the-grotto?si=3208f1ecae6846dcac2bfe9393d86947&utm_source=clipboard&utm_medium=text&utm_campaign=social_sharing 

The glorious stone columns of The Grotto

Episode Transcript:

I want to climb

Somewhere Devine

I’ve been I miner for a crag of gold

Tectonic compressions

And volcanic slime

Keep me climbing at 

A crag of golddddd

And im getting bold

Hello and welcome back to the Rock Behind the Climb, the podcast about the geology of different rock climbing spots. I am your host Quinn “The Jazzhammer” Todzo bringing some rare auriferous luster back to your podcast feed. This episode I am taking you to gold country in the Sierra foothills of California, to discuss the formation of giant stone columns, perfectly vertical cracks, and the great wall of California. I am speaking of course about The Grotto in Table Mountain.

I have wanted to cover this spot for a long time. Just looking at photos of these 100 foot colossal stone columns separated by perfectly vertical cracks that tower over this subterranean pit will  give you a sense of FOMO. And then, you take a step back and look at the formation at large: this giant long and skinny plateau of rock that snakes around the area and looks like the great wall of china, and you can’t help but wonder what the heck created it.

Usually when I go out rock climbing, I have to be the one that brings up the geologic significance of the area to the group, but this time I had people asking me about the rock formation literally as soon as we arrived so lets get into it shall we.

Located in the foothills of the Sierra Nevada right near Sonora, California “The Grotto” is a climbing area on Table Mountain, the great wall of china looking thing I mentioned earlier. Honestly I think calling it a mountain is really a misnomer because rather than a defined pinnacle like most other mountains it has a flat ridge that is about as wide as a football field and snakes around the area for a length of nearly 15 miles. I guess if they were trying to be technical the namers could have called it Table Inverted Valley (For reasons that I will get into), but I guess that just doesn’t roll off the tongue as well.

Table Mountain is well known for a number of different climbing crags, but I am going to focus this episode on the specific area known as “The Grotto”, which exhibits the marquee stone columns. 

So we’ve got this giant 15 mile long great wall of china looking feature held up by giant vertical columns that seem as though they could be supporting the parthenon. So what in the heck is going on here, and how on earth did it all happen naturally.

Table Mountain, Sonora on the way to the Grotto (left), Aerial View (right). Aerial view taken by Gary Hayes by way of source 2.

Table Mountain was formed because a nearby volcano erupted 10 million years ago and filled an existing stream channel with a ton of lava. Then, over time the banks of that river channel eroded, exposing the much more weather resistant intact lava flow that had kept the shape of the old river. This is why Table Mountain has a sort of serpentine shape, because it took the shape of the old river bed. It is also why it is flat on top, because it was basically like pouring a liquid into a fixed container that eventually hardened over. Geologists call this an inverted river or inverted valley because the topography of the river channel is actually higher than that of the surrounding area.

As an aside, miners from the California Gold Rush recognized that Table Mountain covered what could possibly be a gold bearing stream bed, and tried to mine it. Looking through a database of old mining claims, it looks like there was one practically right next to The Grotto actually, but I didn’t see any signs of it while I was out there. I guess there wasn’t a lot of gold found underneath Table Mountain because there were never any major claims. Those silly miners were only interested in the supposed deposits underneath? I mean c’mon everyone knows the real gold is in the incredible crack climbs right above

But I digress. Getting back on track I should also mention that the lava rock that cooled to create table mountain is technically called Latite, but for the purposes of this podcast I might refer to it as basalt which is just a lava rock with less silica and more metallic composition than latite. Basalt, however, is much more readily found and studied so a lot of my sources are specific to basalts, but the same principles behind the creation of the various features apply to both rock types. So I just ask all of you out there when you head to the grotto with your friends and someone mentions how cool the basalt columns are, you don’t have to counter with a snarky “well actually rock is really Latite”, because in my opinion, close enough. 

Ok, back to the grotto. To remind you we left off just when the hot molten lava filled the stream bed, so lets get into how this eventually turned into giant stone columns.

Like I mentioned at the beginning of the episode, the Grotto is vertical crack heaven because the columns are separated by cracks of varying widths giving you a ton of options for different types of crack climbing. The columns themselves are probably about 5 feet wide and have their own climbs on them as well. There is this hellish 5.10d rated climb called AC Devil Dog where you basically climb up the face of one of these outcropping columns by just hugging the damn thing since there aren’t many actual holds. My wingspan proved to just be enough to get me to the top, while hang dogging most at most of the clips.

Me Hanging on for dear life on AC Devil Dog

Most of the climbs though involve jamming your hands and feet into cracks that range from hand size to finger size in between the columns. So how did these columns and cracks form?

Well when lava comes out of the ground, it is a mostly homogenous molten hot mass that flows like a liquid, hence why it took the shape of the river. When it cools, similar to freezing water, it shrinks because the once excited, heated up molecules are now packing more tightly. This rapid cooling and shrinking causes cracks in the rock. Typically these cracks break in ways that create hexagonal shapes. This is because in an ideal world when you have a completely homogeneous mixture cooling at the same rate, it will try to create the least amount of cracks it possibly has to to relieve the internal cooling stresses. So, basically what you want is the smallest perimeter to surface area ratio which is how you get the hexagonal shapes. 

There’s a bunch of videos and stuff on the internet that talk about how much perfect hexagons appear in nature like in honeycombs or snowflakes apparently. They are just the most efficient shape in covering an 2D plane with the minimum amount of perimeter, or in the case of stone columns: the minimum amount of cracking.

The way these 2D hexagons turn into 3D vertical columns (and in turn create vertical cracks) is because the rate of cooling of the top of the lava section cools much faster than the bottom. Since the rate of cooling varies linearly with depth, the cracking that was initiated at the top propogates vertically downwards. 

This is how we get the columns we know and love, because the bottom of the column of rock cools slower than the top, so the perturbance that was initiated at the top will just continue downwards rather than start anew. As with most things in life, these cracks take the path of least resistance, which happens to create nice vertical columns.

But wait!!! Something about all of this doesn’t add up. If you have been to the Grotto you know there are at least 3 things wrong with the idealistic hexagonal column picture I just painted. First of all, none of the columns appear to be hexagonal. I mean there is no way I would be able to grip the corners of AC Devil Dog if they were flaring at 120 degrees. This particular column is square, but I saw others that even looked triangular. Most notably none of them seemed perfectly hexagonal. 

Secondly, those vertical cracks are not the only cracks in the columns. There are huge longitudinal cracks that cut across the columns sometimes causing the columns to break off. On climbs like the 5.11 rated Snake Bite, you actually start on one crack system and then you get to a point where one of the columns has broken off, and have to maneuver yourself onto another crack system while also getting around a small roof. 

Finally, and most notably, the climbs don’t actually top out at the top of of the columns. There is actually at least 50 more feet of volcanic Latite that looks a lot more chaotic than the orderly vertical columns before reaching the top of the mountain. In fact, there are actually a bunch of very difficult extensions on the column climbs that go up this next section of rock. 

So what’s going on here? Well lets break it down (pun intended) piece by piece. Ok so first of all, while hexagons are the ideal best shape, if the lava isn’t perfectly homogeneous in its composition, you start to get cracks that aren’t at the perfect 120 degrees to each other. It really just takes one crack that decides to protrude at a 90 degree angle instead of 120 and boom, your whole system of perfect hexagons is ruined. Take that youtube videos on hexagons in nature

Secondly, what are the other cracks in the columns that cause these things to break? Well those longitudinal cracks, in my observation, are most likely caused by spheroidal weathering. I’m not going to get into it too much in this episode since a) it opens up a whole new can of worms and b) I talked about it extensively in my Joshua Tree episode. Basically, it’s a type of chemical weathering where some of the crystals that make up the rock dissolve over time which cause cracks to expand and edges to round or break off. Some of the columns look like they have bites taken out at the bottom which is most likely from chemical weathering creating a horizontal crack that caused the bottom portion of that column to come tumbling down.

Lastly and most interestingly, lets talk about what is going on with the remaining rock above the columns. Rather than have perfect vertical cracks, this above section is a slightly overhanging with joints and fissures that propagate at random. If I didn’t know any better I would think that this was a different rock type or at least part of some different event. That’s how starkly different the upper section appears.

However, this is actually pretty common with cliffs that exhibit columnar jointing. In fact, geologists have broken down columnar jointing systems into different zones. The zones with the columns are called the colonnade and the ones with the irregular cracks and such are called the entablature, and it almost always happens where the entablature sits on top of the colonnade.

The reason the entablature exists is because in order to have those perfectly vertical cracks, you need every part of the rock horizontally to cool at the same rate and then cool slower and slower as you go further down. If for some reason the cooling process is disturbed like a particularly long and penetrative rainfall event, the isotherms (or regions with similar cooling rates) can be disturbed causing the cracking to happen haphazardly. This is more likely to be the case towards the top of a cooling lava rock section where the cooling rock is most disturbed by the elements. 

So to recap: we have giant columns because of regular cooling of a homogeneous lava. However, since in reality the rock doesn’t cool regularly and isn’t perfectly homogenous, it didn’t result in perfect hexagonal columns from the top down. 

But hey, if we wanted things to be perfect all the time we probably wouldn’t make it as climbers, or geologists, or enthusiasts (big shout out to the climbing and geology enthusiasts that listen to the podcast who don’t actually climb or go to these places that I talk about).

OK to finish the episode, I want to circle back to the beginning and talk about where the lava that filled the stream bed even came from, because as you will see, it is very closely related to a bunch of other rock climbing spots in California.

The lava actually wasn’t from a volcano like we normally think of them. It was from an ancient fault line pulling apart and letting magma just kind of spew outwards. 

Essentially the land mass of California had been in a state of compression which created the volcanoes and volcanic fields of climbing areas such as Mt. St. Helena, Pinnacles, and Bishop Peak down in San Luis Obispo.

However, just like when you squeeze a spring and let go, after being squished in compression California went into a state of stress relaxation meaning that the land literally spread back out. This stress relaxation opened up an old fault line in the area around Table Mountain causing lava to spew out and fill the ancient stream bed, thus creating Table Mountain.

I think the interesting takeaway here though is that all these crags that I just mentioned including the grotto are related by being formed from a similar event. Granted Table Mountain was more of a reaction to the events that created those other 3 places I listed. I find it fascinating because none of these climbing locations look or climb like each other, but because volcanoes can have many different ensuing rock types, these similarly created climbing crags take wildly different forms. 

You could honestly put together a pretty sweet road trip down the state of California and hit all of the coastal volcanic climbing crags, and come out a very well rounded climber. Like you could practice your crack climbing at the grotto, get ripped on the pumpy climbs at mt st helena, practice patience and slow careful climbing in pinnacles, and then finish with some sporty long link ups down at Bishop Peak. And all of these climbs would be connected by a common geologic event, which I dont know for me is freaking cool.

With that thanks so much to all of you listening! Feel free to reach out to me with any comments, questions, or critiques through any of the provided avenues in the episode description. Also, if you follow the link to my blog you can find the full episode transcript with photos. Before I close the episode I want to leave you with this quote from 1882 in a journal entry titled “The Ancient Man of Calaveras” W.O Ayers that talked about the gold mining at Table Mountain. 

He writes: The question occurs to us: How came Table mountain to exist? That basalt, when it was erupted, was fluid like other lava. How could it be piled up so thick and so abrupt (for its sides are often perpendicular) on that high mountain ridge, and remain there? Why did it not spread itself out laterally and cover the plain? But one answer to these questions can be given: There was no plan. 

Thanks again for listening, and I’ll catch you guys eventually on the next one. Jazzhammer out.

Sources:

https://www.tandfonline.com/doi/full/10.1080/00206810902978265 

https://www.researchgate.net/publication/233188590_An_in-depth_look_at_distal_Sierra_Nevada_palaeochannel_fill_Drill_cores_through_the_Table_Mountain_Latite_near_Knights_Ferry/link/00b4952a03565585bf000000/download 

https://www.jstor.org/stable/pdf/2449590.pdf - ancient man of the calaveras

http://hayesg.faculty.mjc.edu/Gold_Rush.html - gold rush

https://www.kqed.org/science/8032/how-californias-warping-microplate-makes-its-faults-creep - Sierra Microplate and creep

https://touchstoneclimbing.com/trip-report-table-mountain/ - Table mountain climbing history

https://ohp.parks.ca.gov/?page_id=21534 - gold mining around table mountain

https://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=10214295 - punch bowl gold mine that was right next to the grotto trying to mine underneath the mountain

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2007JB005018 

https://watermark.silverchair.com/2068.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAApwwggKYBgkqhkiG9w0BBwagggKJMIIChQIBADCCAn4GCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMdfhpYBYOqLUemreIAgEQgIICT5wDzQhYNYh6cJWvFWyIDZhaog6ksf0Bz0VTcw39Ap0VdGjyAURXKFI5eT49dhrN43zrSBANBjxOjnZMfjy-v2VPaAhF5HxQR3ciqSVpNIsALXPrMRQ-IIObsyk375MIdmewVpUSmMJCaMeHYW95a_OdMRm9p2yfH0UDqcUNXNniCARxwPMy4JqeIh38P7rL19FGkPFR5-eq85NCAEdkxQmQdAHfKmyfB4xEcH-mayn6T_rWwWlXbwysml2JqNpEahhA_tje490U80j56tm6bNl4Mn4RfUHO628DbWtBtkpkBdEYy_VGH3sC4VeclPY7Uv9wzkKFr3W8s9cyEx5FUTVLM8HVqBzvLrmb1d0_joqjI6hOwC87hRs02fIlK6bfGLoHaWUzQNcuBEBP74wgZZR8YjcXiCxaUxMrejUfBbjRWXTFWOrzI6BfzPkr7l-6EmWTMUtpyMTQuBdTNhQVARxh5JbUm4MU5p4EsW1mTgfm6nOuFSXCm2BsoJjdzAWBZwAbivOqvucarJgriZl4a510FtZ3gMtY2MasUrKMDve7NRgWHenGKefQAL1248WEcBGY4rJmb_uxID98EB_6AraFvp1apQQ9sYnng4Q-ebBZwF-2GhS7IBT4Jzzdkyjn1ESd2-t5QHcqCGRjRJ_BSLIXRbwdaoeAP-64ueOwcIdUn_IdyweDB_ualOUGPXe0VihS_uSBf3tzocwPOoph9Pdmhv1YPezORP66BYNyUj5b_BTfQMHRTpuIHelDTNid1gq4glLDVzJbsq04pFuMbA - transpressional

https://pages.mtu.edu/~raman/SilverI/IRKeweenawRift/Columnar_Joints/Columnar_Joints.html - colonnade vs entablature

The Struggle to Protect the California Coastline Episode Transcript and Notes

Episode link: https://soundcloud.com/quinn-todzo/the-struggle-to-protect-the-california-coastline

Note this is a painting of the cliffs in Malibu, CA (which is not where this story takes place)

Episode Transcript

California is being swallowed into the Pacific Ocean, and it is really hard to stop or even slow down that process. With sea levels that are rising at increasingly alarming rates, 800 miles of shear beach cliffs along the California coastline are eroding at rates as much as 5-10 feet per year. From houses to highways to important infrastructure, there is a lot at stake on the edge of California, so what are we doing about it. Well, today I am going to bring you a boots on the ground story of how we are trying to protect our coast from erosion, and the difficulty in doing so.

Before I go any further I do want to mention that I am not going to really talk about rock climbing in this episode. As I discussed in my last rock behind the climb episode on Mickey’s Beach this issue is affecting some of our crags. But, today I ask that you indulge me a bit, because I think my small scale story of trying to protect just one guy’s house from collapsing into the ocean will give you some perspective on the massive issue that is trying to mitigate coastal erosion, so stay with me.

So, the project that I am working on is for a single story home built right on the edge of a beach cliff. About 15 years ago the homeowner constructed a shotcrete based seawall embedded into the existing bedrock to prevent the erosion of the cliff and subsequently his house collapsing into the ocean. About a year ago, though, my geotechnical engineering and geology consulting firm got a call that a huge cave had formed underneath the previously constructed sea wall.

Basically the rock that the original sea wall was constructed on top of was more erosive than the concrete wall above, so the ocean continued to carve into the rock underneath burrowing a 4 foot high, 80 foot wide and 26 foot deep cave underneath this guy’s house. If we had let this cave get much deeper, it could have seriously once again endangered the house from collapsing into the ocean. The first order of business here was to fill in the cave with high pressure shotcrete, or concrete that you can spray out of a hose. A couple months after the cave was infilled with shotcrete, our client secured the permit to begin working on the construction of a new sea wall that we designed to protect from further undercutting. This is where I came into the project.

As an engineer out in the field my primary role on a project like this is to ensure that our design is being constructed correctly. In an ever evolving environment like this one, I’m also the guy on the ground to point out anything that doesn’t make sense in the design in a constructability sense and help make changes if necessary. In my line of work there are a lot of assumptions made when designing structures in an ever changing environment, variability within the construction contractor, and high stakes, they tend to send someone with engineering or geological knowledge to do the inspections, because the directives are never simple. So that’s what brought me out.

But before I get any further, I want to take a step back and talk about why the California coast is eroding so quickly, and traditional ways in which people try to protect coastal bluffs. So a lot of the coastal bluffs are made up of marine terrace deposits. These are rocks that are comprised of sands and clays originally deposited by the ocean, and now make up the weak sedimentary rock near the shoreline. Through millions of years of tectonic action these marine terrace deposits have been uplifted to form the coastal mountain ranges along the California coast. However this doesn’t explain why the cliffs are so shear. This comes because of wave action from the ocean. Waves constantly bombard these weak sedimentary beach cliff rock formations at the bottom eventually causing the entire cliff to shear off. As sea levels have risen and fell over millions of years, they have created multiple levels of sheared beach cliffs separated by nearly flat platforms that are a result of the ocean spreading out the collapsed material to make a terrace, hence marine terrace deposit. All of this is to say that we have constructed a lot on top of the flat, weak terrace deposits that are now being reconsumed by the ocean.

So how do we protect the communities and infrastructure that we have resting on these unstable beach cliffs?

Well one idea is to get out in front of the ocean. The primary cause for the eroding cliffs is giant waves crashing into them, so why don’t we just take the waves, and put them somewhere else. So we’ve actually tried this. There are structures called jetties and breakwaters which are these barriers made out of giant rocks or chunks of concrete that extend out off the coast perpendicular into the ocean to hopefully curb the wave action coming in. You see these a lot near harbors. Anyway there are a number of major problems with these structures including problems with surrounding ecology but they can actually have a pretty negative effect on coastal erosion.

These structures can do a good job of redirecting some waves from pounding the coastal area you want to protect, but they can also trap sand from being able to land onshore. Now I know what you might be thinking right now: “I hate sand. Its course, and ruff, and irritating. And it gets everywhere.”. However, the reality is that sand is actually really great for protecting our coastlines. A built up sand bar can act as a buffer to block waves from running up against the cliff or at least slowing them down. So these breakwaters and jetties can actually do more harm than good in terms of preserving the cliffs, because they trap the sand from landing on the beach

Piggy backing off of this discussion, another solution that has been used is to literally pump more sand onto the coastline in a process called dredging. This process is actually very costly though to pump enough sand in place, but is helpful in that it maintains the coast in a more natural way than building structures.

In my opinion, one of the most effective ways to protect a sea cliff in general is to build a riprap buttress. This is basically a pile of giant super heavy rocks that get piled up next to a sea cliff to protect it from getting pounded by waves. These are actually really effective in protecting the sea cliff, but they can actually redirect waves to be more forceful on the sea cliffs adjacent to where they are placed. Also they look like crap and in many cases decimate any hope of having a functional beach that can be used by the public.

That brings me back to the project I am currently working on, a concrete based sea wall. Concrete sea walls are exactly as they sound, vertical walls that stand between the sea cliff and ocean. In many cases including the project I am working on this is paired with a shotcrete finish meaning that the weak friable rock is sprayed with concrete to create a façade that holds everything together and still kind of looks like the cliff face so it still has the marine terrace feel to it. On top of that, these cliffs are anchored by a series of soil nails or tie back anchors which are huge strands of steel that are drilled into to the cliff side and tensioned to hold it in place and protect it against a slope failure.

All of this was in place in 2005 when our client’s original wall was constructed. And it worked. Actually pretty well. However, as I discussed in the beginning of this episode, the ocean, not to be outdone, actually burrowed a cave underneath the sea wall with the constant swell forces. The rock that the old sea wall is founded upon is weaker than the concrete wall, so the ocean found a way to still eat at the cliff side. However, that old wall still remains hanging over where the rock used to be.

That last bit of background you need to understand going into the project has to do with the California Coastal Commission, which is a California state regulatory commission that regulates the land use on or near the California coast, and oversees any development near the shoreline. This is great in theory as it helps protect the coastline and ocean for the general public. However, it also makes it so there are a lot of hoops you need to jump through to get and maintain a permit to do construction like this. As I go forward with this story, you’ll see what I mean.

Ok, now let’s get back to about a month and a half ago when I was first brought out on the project. Our clients had just secured a 2 month long emergency permit to go forward with the new sea wall portion of the project. Without a ton of forethought or planning, the construction contractor was sent out there to build this thing. After all, they just had to dig a 4’ deep ditch, put in some steel, and spray it down with shotcrete. Boom. Easy. Right?

Eager and ready after a long car ride down to the project site (which I’m not allowed to tell you the exact location of), I was immediately turned around. The tide was way too high. In a project where you trying to prevent the effects of the ocean slamming against the area where you are building, it is likely that the work area is going to be flooded with tidal water. And regardless of whether you think that we should have just thown on our wetsuits and got going, nevermind how dangerous and polluting it is to operate heavy machinery in the ocean like that, it is against our permit to work when there are still tidal waters present in the work area.

There are very few times when the tide is low enough for us to get out there and work, so the solution became to try to place temporary barriers seaward of the cliff to try to extend the time that they could actually get work done in those short windows of time when the tide is receded enough to work. Without the barriers, they only have roughly 3 hours of time, but with the barriers they were looking to extend that by at least a few hours.

However the idea to place temporary barriers utterly failed. Their first temporary barrier were these giant 6 foot tall bags filled with sand and rocks that they would drag out every single day. At the beginning of the day carry them out via crane and bobcat loader, and every day take them back to the staging area up on top of the cliff. This process of carrying the giant bags of sand and rocks out and back took so long that it actually afforded the contractor next to no time to actually work.

So, after that they decided they would try putting giant blocks of concrete out on the beach plane and leaving them in place overnight so that they wouldn’t have to waste so much time moving these barriers. Well, even though these were multi ton giant blocks of solid concrete, they were no match for high tides and large swells, and they were nearly thrown into the side of the cliff after just one night. They were then promptly removed.

It was also during this time of experimenting with the failed temporary barriers that the contractor also realized that their initial plan for digging the 4’ deep ditch called the keyway was not going to work, because of a few details that proved to be quite problematic. First, by nature of the permit the new wall cannot extend outboard of the original 2005 alignment, meaning that the wall can’t be constructed in front of where the old one overhangs the cave that formed. Also, by nature of the permit anything that the contractor chipped whether it be old concrete or the underlying rock, has to be offhauled from the beach into a dumpster on the road.

They initially planned on using a mechanical excavator to chip away the old overhanging shotcrete wall to then use a different attachment on the same excavator to dig the keyway. This proved to be ineffectual because it takes a really long time to chip and off haul the large amount of overhanging shotcrete needed to clear an area large enough for us to work, and there was about half of the length of the wall couldn’t even be accessed by the excavator because it cannot track over this one section of beach area that is mainly just rock, no sand.

I’m not sure if any of that made sense to you, but in effect we were one month into our two month permit and had barely even broken ground. Around this time we had a particularly excrutiating daily project meeting These meetings had transformed from simple daily check ins to 2+ hour tirades with a lot of yelling and finger pointing. Anyway, I remember they were discussing another option for temporary protection from the tidal waters when I brought up that regardless of whether or not they fart around with another shoring system that probably won’t work and mind you doesn’t actually do anything to construct the wall, they do have time to at least get some stuff done with a bunch of guys with jack hammers and rock drills. Honestly it’s not really my place to comment on the means and methods in which this project gets done, but whatever, things were getting ridiculous.

Luckily my point was taken well, so me and the now third site supervisor from the contractor devised a plan of attack where some workers would go ahead and predrill some pilot holes with the rock drills to release the confinement in the rock, and then guys with jackhammers would come through and chip around those pilot holes to excavate the rest of the trench. We called this method the “swiss cheese” method because the predrilling made the excavation area look like a block of swiss cheese kinda. Anyway, this actually worked pretty well and soon enough we were making progress, especially as they continually sent more and more workers out to aid with the operation.

However, it may have been too little too late because the reality is that we were only actually able to work for about 3 hours a day maximum. In fact there have been entire weeks where the tide is too high to be able to work at all. On top of all of that, before we could continue to excavate downwards, each day had to be started with shoveling out all of the sand and rocks that collect in the keyway each night. So even with the revolutionary swiss cheese method, progress has been slow.

And that’s not all. There are still battles over the constructability of the wall during our limited permit window. As of right now we have a few sections of the wall mostly trenched to depth. No steel has been placed, and no concrete has been shot and our current permit ends in a few days.

Now you may be thinking that the contractor is to blame and is inadequate, but the reality is that they weren’t given a whole lot of time to prepare for this work because the permit was issued so close to the actual start date. In fact, we have had a number of other construction contractors check out the project and none of them have given any better ideas than what the current contractor is doing.

Maybe you are thinking that the Coastal Commision is to blame by instituting too many regulations and by making us jump through a lot of hoops during the permitting process.

The reality is, though, that this project is freaking difficult, no matter how you slice it. Lucky for us, we have a client that is really committed financially to building this wall, because a project like this isn’t cheap. And for what? The wall is designed to last maybe 15-20 years. All of the prior infill, this wall which is going to take much longer than expected, and a number of tieback anchors all for another 15 years.

Now you might be thinking to yourself is it worth it? I mean obviously for this guy it is. He gets another 15 years in his beautiful home. But is any coastal remediation worth it if we the public are the ones who have to pay for it? I mean this is a stretch of 80 feet among 800 miles of bluff on the California coast, and these 80 feet are causing a lot of smart people some big headaches.

Well, you wouldn’t be the only one to think it’s probably not worth trying to protect the California coast. I mean who cares if a few rich people lose their seaside homes. Really, just say screw it and let the ocean consume everything in it’s path. In places like Pacifica, California which is just south of San Francisco, the 80 foot cliff is receding at such an alarming rate that they literally had to abandon apartment buildings and homes to demolish them before the ocean did so. I linked a couple of interesting articles on this from 2016. Also, as many of my friends like to point out, the Big Sur coastline in California is consistently plagued by rockfalls and landslides that make the beautiful highway 1 impassable. It’s just cheaper and more feasible to just roll with the punches than try to actually fix the cliff in these areas.

But in reality there can be problems with the do nothing approach too. I mean people aren’t just going to let their homes get destroyed without some sort of legal battle. Most of the time when something like this happens it is on the city or county to reposses the property that is subject to falling into the ocean, meaning that the public has to purchase the buildings that can’t be saved. Also it’s not like the ocean stops eating away at the cliff. I mean there are places in California where the ocean is eroding the cliff at a rate upwards of 5 feet per year without defenses, and sooner rather than later that will cut past the beautiful sea side homes, and into valuable infrastructure and more houses.

So right now, my view on this is nuanced. I think there are certainly places that are not worth saving. Rural locations where there isn’t too much at stake. But, in more urbanized areas it can be hard to justify going down without a fight, and decisions should be made on a case by case basis with engineers, geologists, and other scientists at the forefront to weigh the options.

I’m going to be honest, I’m not too sure how to close this discussion. We are going to be faced with some really tough decisions in the coming years concerning this coastal erosion issue and I am sure that this podcast that you are listening to right now will not be the last you hear of this.

But thank you so much for listening. I know this is a bit of a divergence from the rock behind the climb but I haven’t had too much time to climb as of late because of this project, but I promise I have more rock behind the climb in the works. Please let me know if you liked this episode, and especially if you are curious to hear how we finally get this wall completed, a part of the story that I don’t even know yet. Otherwise, thank you so much for listening and I’ll catch you on the next one

Jazzhammer out.

Links to articles and Resources

More on Coastal Protection 

https://pubs.er.usgs.gov/publication/70033640 

https://www.researchgate.net/publication/285969581_The_impacts_of_coastal_armoring/link/568fe4b708aee91f69a13733/download

 Pacifica, California abandoned communities

https://abc7news.com/in-pacifica-demolition-crews-continue-work-on-an-abandoned-apartment-building-crumbling-cliff/1243926/

https://www.dailymail.co.uk/news/article-3455513/Homes-teetering-brink-California-cliff-demolished-six-year-battle-destroyed-comes-end.html