Southern California Geology | A Volcanic Plug of Dacite Columns

[@davekim6549]

I'm a mailman who has been delivering mail in the area where this volcano is. I've wondered for years the history of this volcano as I drove by it daily in my mail truck. Lately I became curious about this area and found your video. It was just what I was looking for. Now I know so much more regarding the area I have been delivering mail for years in. Thank you.

[@socalpal8416]

Before the developers came in, this area was pretty much wilderness. We used to ride our dirt bikes here as well as leap into the lake from it's rather high cliffs. This area was a rock quarry at one time hence the lake. Glad to see it's been preserved. Fun video mate.

[@ryanfritts1574]

Remember the paintball and bmx

[@joshmcdonald9592]

i was wondering if that was the quarry. doubt i could find it again.

[@socalpal8416]

@@joshmcdonald9592 Easy to find Josh. Just East of Carlsbad and South of Hwy. 78.

[@sdmike1141]

WOW! How friggin cool! I was thinking while watching a recent Nick Zentner video of Cascade geology, ‘it’d be cool if someone covered SOCAL geology in similar fashion”. BOOM! Thanks for posting! Very well done!

[@geologicallyspeaking]

Well that's an incredibly kind compliment. That man is one of a kind!

[@sdmike1141]

@@geologicallyspeaking Yes, a nice bar to aspire to as a human! By the looks of your videos, you’re pointed in the right direction!!

[@miqsh70]

He might cover some with new Baja BC A-Z series, starts next week 16 November!

[@Naturallystated]

Never heard the description of the transition from subduction to transform described and shown so clearly. That info-graphic should be required in all SoCal intro to geology courses.

[@geologicallyspeaking]

I agree. All credit to Tanya Atwater for her great animations.

[@tonidougsmith-congratulati1522]

Awesome! Didn't know there were columns in the plug. When you showed the spherical weathering shot, I thought you had found a skull!!😂 very informative and you make it easy to understand. So glad you survived!! Mom

[@geologicallyspeaking]

💀 Hahaha! I can't unsee that now. Thanks Mom.

[@dr.OgataSerizawa]

@Toni &Doug Thought I saw a skull too in the spheroids. Freaky!

[@1234j]

Excellent again! Thank you for scrambling the risky heights to get up close - great to see those joins. Cheers from England.

[@geologicallyspeaking]

Thank you kindly!

[@Kompressor989]

Wow. Great find Todd! As you told the story and then explained, light bulbs kept lighting for me. Columnar Dacite. I have seen the Columnar Basalt in the NW, but, I never thought about Dacite cooling and developing columns. Geology is made cool by teachers like you. Great Video! Oh, and thanks for not falling off the wall.

[@geologicallyspeaking]

This is the best feedback you can give me; light bulbs lighting up is my goal. I endeavor to make, what could be complicated concepts, easily understandable to those not necessarily well-versed or familiar with geology.

[@dr.OgataSerizawa]

@@geologicallyspeaking I gotta say, you’re doing a remarkable job of explaining👍

[@charliedoyle7824]

Great job zooming in on the map, and with the charts. They make your field trips even better!

[@geologicallyspeaking]

Thanks, I agree with you. Visual aids while explaining concepts are so beneficial. Thanks to Tanya Atwater for making those great animations.

[@vernonvillasenor6338]

I am an armchair geology fan and absolutely love your videos! I live in Southern Orange County. Would you ever consider hosting a field trip? Any ideas on if any geologists do local tours?

[@geologicallyspeaking]

Thank you! That's an interesting idea, I'll let you know if I decide to do that. I attended a geologist-led hike at the Aliso & Wood Canyon Wilderness area in Aliso Viejo years ago, but I don't know if they host them anymore. There are 4 geologic formations there!

[@laurenrobinson9219]

Yes, more videos, please! Would be so cool if you went to different places around the country and tell us about althe cool formations you see!

[@rdgurule]

I live at the west end of the Columbia R Gorge. Very lucky to see all the basalt layers and columns. This video was very informative. The Nick Zintner KZbins are amazing.

[@geologicallyspeaking]

What a beautiful area you live in; I've yet to get up there and visit. Yes! Nick Zentner videos are the absolute best.

[@johnnynephrite6147]

Lived in SD County since the early 80s and never even heard of it. Driven by there a few times and thought it was just remnants of an old gravel mine.

[@TnTMyers2010]

Thank you so much for a very informative and easy to understand geology trip!

[@JonnyHuman]

This was fantastic. Thanks for this -- more pls! :)

[@geologicallyspeaking]

Thanks!

[@oscarmedina1303]

Thank you for posting your video. Me and a bunch of geology enthusiasts visited the location just because of your video. Six of us Zentnerds explored the volcanic plug. Your video helped a lot.

[@earthandtime5817]

Excited to explore this area next time I am in Carlsbad. Thank you for the informative and fun video :)

[@geologicallyspeaking]

Thanks for watching! Yes, give it a visit!

[@earthandtime5817]

Finally made it. What a cool hike and amazing geology. The factor columns were a first for me. However I couldn’t find the flows down the hill. Was hoping to see those also. Maybe next time. Thanks for the info.

[@earthandtime5817]

I posted an episode from here as well and plugged your channel in the pinned comment. Thanks again for all of the great info. Hope we cross paths sometime.

[@rogercotman1314]

Thanks for such an informative and educational video. Loved the effort to hike up to the various locations for closeup observations. 115 like ...........

[@geologicallyspeaking]

Thanks for watching and the feedback. I aim to educate, entertain and please!

[@rogercotman1314]

@@geologicallyspeaking Thanks, found some basic information: Columnar jointing forms in lava flows, sills, dikes, ignimbrites (ashflow tuffs), and shallow intrusions of all compositions. Most columns are straight with parallel sides and diameters from a few centimeters to 3 meters. Some columns are curved and vary in width. Columns can reach heights of 30 meters. Most columns tend to have 5 or 6 sides but have as few as 3 and as many as 7 sides.

[@stevenrey56]

Your an allstar! I found that very interesting.

[@geologicallyspeaking]

Thanks!

[@richcolby4184]

Very helpful, I truly appreciate the effort you have made to educate so many. Thank You, you succeeded with me, Rich

[@geologicallyspeaking]

Thanks Rich!

[@davehalliday9399]

Great video thanks for sharing.

[@eddieagnich1875]

Very informative and interesting. I really enjoy these little facts of nature. Thanks,

[@Naturallystated]

Take a trip out to the Southern edge of the Salton Sea to discuss Obsidian Butte in the Brawley Seismic Zone.

[@geologicallyspeaking]

I know the area well. It's on my list to create a video.

[@dennisyardn1ten238]

@@geologicallyspeaking On the way to Obsidian Butte or back from it, go through the San Andreas fault zone via Box Canyon at Mecca, CA. It runs between Mecca and I-10. Lots of thrusted and folded sediment layers.

[@geologicallyspeaking]

@@dennisyardn1ten238 nice was just here 2 months ago. Made a brief video and some pictures on my Instagram channel.

[@IDNHANTU2day]

Looks like I just found another geology channel I like am subscribing to. Thank you!

[@geologicallyspeaking]

Thanks so much!

[@mikethierry725]

Just flipped your channel . And I tripped out on the fact you were in Carlsbad . I live and have been in Carlsbad since 84 . I found just by chance and watched the video .keep it up . Maybe talk about the old hot springs that are around the lower dam towards the coast .that's how aqua hedionda got its name.n

[@geologicallyspeaking]

Thank you and thanks for the tip!

[@gwolfeman]

Another great explanation and visuals. Would love to see the story of what happened from the badlands in Riverside thru the Hemet valley into Parris. 🤙

[@geologicallyspeaking]

Thank you. And thanks for the suggestion. Are you talking about the San Timoteo Badlands near Moreno Valley?

[@gwolfeman]

@@geologicallyspeakingyes, exactly

[@jessilynn9760]

These videos are great. I have been watching geology videos here for a long time now, and these have helped me grasp geologic processes in the real world better than any other videos I have seen. They have also made my hikes way more interesting. Thank you!!

[@miqsh70]

There is a very similar rocks formation at Bowling Beach in the North. Looks so cool!

[@ryanfritts1574]

Great place to party when I was a kid

[@socalpal8416]

After diving/swimming at the lake, we'd head over to the RR trestle at Agua Hedionda Lagoon in Carlsbad to dive into the water. Best thrill was waiting for a passing train and jumping off just as it's wind shock wave hit you. Seemed like you sailed out 20' from the trestle. Good times.

[@ryanfritts1574]

@@socalpal8416 I would fish there but didn't try to beat the train

[@socalpal8416]

@@ryanfritts1574 lol.......guess I was a lot crazier back then. funny, 'cause it all made perfect sense at the time.

[@tonecola4552]

Definitely, many wonderful memories! Grew up in Carlsbad over the hill from the quarry, wish I knew them it was a volcano great view and great party spot.

[@tonecola4552]

You have family here if so next time your in town check out the waterfall below there to the north. There was another quarry there next to the I 78. Now there's a Walmart and a kohls well drive to the kohls sign and look over the fence. It was way better when I was a kid although still cool to check out. We would follow the river west through the marsh . There's still a couple of lakes there too. Actually now that I think about it the whole area is interesting. Also check out De Luz Canyon, really cool.

[@geologicallyspeaking]

Thanks for the tips Tone Cola. I'll have to check it out.

[@astrogeo1]

Very interesting video ! Watching this from Norway. We have such magma / lava columns in parts of Norway too, not basalt. Strangely not even recognized. Been talking to top geologists about it, they hardly believe me. Much of the Earth's surface have yet to be explored by a discerning eye.. 🧐 🌍

[@geologicallyspeaking]

In California I've seen columns made of basalt, andesite and now dacite! ....so far!

[@johnlord8337]

need to show the grapevine basalt triangle holding back all of the LA-Baja peninsula movement - and reason for the Richmond earthquake swarms ... as you show part of it is torn off and spun around in your video model. And how it was formed, and what is its immediate and future existence with tectonic forces being applied by the Pacific Plate, North American plate, and such remants of the Farallon plate underneath it ...

[@Rachel.4644]

Quite the field trip. Great visual to explain the transformation! Really cool perspectives. So much to see in your area....I'm starting a list.... 👍🏻 Spheroidal weathering...huh! Joshua Tree boulders are so beautiful. As always, thank you Todd.

[@geologicallyspeaking]

Thanks for the kind words, Rachel.

[@stevep5736]

Tremendous video, nice work!!

[@RR_1138]

This is probably one of the most unfamiliar areas for me being in SoCal. Did not know some areas West of the 15 , very cool ! Great info of North SD

[@geologicallyspeaking]

It blew my mind when I read about, and visited, it as well.

[@canadiangemstones7636]

That vertical jointing is endlessly fascinating, thanks for sharing awesome geology!

[@Romasulmona]

That vertical jointing is biology......from giants....DNA SAMPLE WILL clearly identify and end all this nonsense

[@ryanbabin5178]

Love the geology lessons, and love the Cali Roots music on your vids. Greetings from Big Bear Ca! Peace Brother✌🏽

[@virgo714]

thank u for sharing

[@geologicallyspeaking]

Thanks for watching. 😀

[@cbwoolley]

Brilliant and informative.

[@dakotarose8990]

Thanks so much for posting this; it's really interesting :-)

[@geologicallyspeaking]

Thanks for watching. 😀

[@soaringbob]

Glad to have found another geology channel covering southern California. I've been a follower of Prof Nick Zentner covering the Pacific Northwest, Jeff Williams covering mostly gold mining geology in Arizona and Nevada, plus there is Myron Cook's channel in Wyoming. Another YT channel covering SoCal is Joseph Wright, but his videos are few and far between. I've never heard of southern California volcanoes other than the cinder cones and lava fields out in the desert, so this one near Carlsbad is a surprise. I have found boulders that look like red lava up Whitewater Canyon north of the I-10 in the Mt San Gorgonio foothills, and wonder how they got there as the nearest volcanic hills are about 15 miles away and northeast of Pioneertown. I wonder if these boulders are related to the nearby Red Dome up Whitewater Canyon! Also near the entrance to Whitewater Canyon, I remember as a kid finding fossilized clams on the ridge labeled as Painted Hills. The elevation there is around 2200 feet now, but could this have been the shoreline of an ancient inland sea?

[@geologicallyspeaking]

Thanks for watching! I'm a big fan of all those channels you mentioned. I love your musings about White Water Canyon; I've been there only two times, briefly, and didn't have time to really explore. So much geology, so little time.

[@harmonyway09]

Awesome video !!! Awesome knowledge !!! Thanks for sharing !!!

[@evekinglehman84]

Thanks much. Good explanations. The first time I saw spheroidal weathering was at Yosemite. An easy hike up Sentinal Dome shows a huge example of the granite being weathered in a spheroidal shape. The granite sluffs off in curved sheets, big and small. Thanks also for including the Felsic to Mafic chart. Good Job.

[@geologicallyspeaking]

Thanks! The spheroidal weathering up in Yosemite puts this to shame. What a beautiful area!

[@drbobinski1]

Thanks Tod, great episode. Just grabbed me a really beautiful piece of Sandstone from Sand Dollar Beach on my way south from Big Sur last week. Check out the beautiful metamorphic green shiny bluff along the south of the beach (composed of serpentinite and talc?). Worthy of one of your excellent videos.

[@geologicallyspeaking]

Love serpentinite outcrops! Thanks for the tip!

[@Migalido]

Dude, I guess I am lame too. I grew up in Oceanside and did not know that was right next door.

[@stevemercer6198]

Cool place thanks 🤙

[@JCSaves714]

I live about an hour from Carlsbad towards LA county.. got a crazy story..I have been having (literally) the same dream for 20+ yrs (since I was 10yrs old). And it’s about lava, and it’s not a pretty dream. So I grew up terrified of volcanoes! I truly hope that volcano wake’s up. Or any dormant volcano in Cali! Have fun exploring! And you need to go to Morro Bay. Another gorgeous town with a dormant volcano and I think it’s a lot younger too 😂

[@geologicallyspeaking]

Scary dream. Don't worry, no evidence that these volcanoes in SoCal will flare up. The only ones that might would be on the southern shore of the Salton Sea, but they're small and would be extensional eruptions. I've been to Morro Rock several times, which is also a volcanic plug. What's interesting is that it is one of nine volcanic plugs (some say 23!) that trend NW-SE almost in a straight-line across the landscape!

[@kathywilliams785]

Wonderful video (again), thank you so much!

[@antoniodelrio1292]

You're making me want to travel to see SoCal! Very interesting.

[@juliamarple3785]

That's pretty cool!

[@davidemmons7154]

I did my senior thesis in geology in 1974 at San Diego State University. Did you notice that the jointing is perpendicular to the sandstone at the contact? There are pinkish red rattlesnakes like those on Catalina Island. It was a rock quarry. Nice video!

[@solorana1]

This is great. I am getting ready to move back to San Diego from Lone Pine. 😃

[@geologicallyspeaking]

Welcome back! I love Owens Valley, but you can't beat the weather in San Diego.

[@purelyrod9310]

Yes! Thanks for bringing it once again bro. Excellent location choice. I had to look up the difference between tonalite and granodiorite midstream watching this LOL…pretty similar, guess the latter is “intrusive” and the former is plutonic, so hopefully help distinguish in situ. You ever make it out to Saline Valley? Really hope that your YT success continues to grow and you keep these videos coming, they are fantastic!!!

[@louiscervantez1639]

Good stuff

[@AndrewJ951]

The Paloma Valley Ring Complex in between Murrieta and Menifee would make for an awesome video.

[@geologicallyspeaking]

Thanks for the tip Andrew. I'll check it out. I love the Perris Block of the Peninsular Range; great stuff out there.

[@MostlyIC]

very much enjoyed this video!. they say most of geologic history is recorded in sedimentary rock, but here we have some recorded in igneous rock, very interesting !

[@geologicallyspeaking]

Thanks Peter.

[@wtglb]

So interesting! I wonder how high that volcano was at its peak.

[@geologicallyspeaking]

Right?

[@gerardoavila681]

Love your videos. ❤ Can you please come to Ventura County and make a video on the Topatopa Mountains and the Conejo Montain volcano?

[@bradriney919]

Great Video by the way!

[@SamtheIrishexan]

Great video hope ya enjoyed making it

[@dennisyardn1ten238]

Congrats from a SD County Zentnerd. Something completely unknown to me as a 40 year resident of San Diego and an Earth Science graduate.

[@edwardhanson3664]

I am encouraged to see inspired, enthusiastic science teachers, especially in geology, I majored in that at Chaffey College in Cucamonga. 69-72 My professor was a great photographer and knew his material..

[@KT_571]

Thank you for the great and informative videos! Please make more similar videos about the popular national parks! You're handsome, by the way!

[@Roy-uz9ri]

This video is so full of information

[@pacolote]

I have a rock sample that looks just like that dacite, I wasnt sure until now, thanks

[@karentrimmer]

How does this compare to Cucamonga Peak? I am from Ontario, CA, and studied geology at Chaffey College where I was taught Cucamonga Peak is a volcanic plug. When I would try to expain that to friends they didn't believe me. Also, how do the Pisgah crater and lava tubes relate to the San Bernardino Mountains?

[@geologicallyspeaking]

Thanks for the questions Karen. I'm unfamiliar with those areas, but it sounds intriguing. I'll have to check it out.

[@tolson57]

I have always been fascinated by columns. I lived in SoCal for 50 years and never knew that I could find columns in Carlsbad. Thank you! Are there other volcanos in San Diego County like this?

[@geologicallyspeaking]

I was so surprised too when I found out about this. I'm not familiar with any more columns in San Diego, but there is an outcrop of andesitic columns in Laguna Beach right on the coast (Crystal Cove State Park).

[@joshyosfan9597]

Can you do Vasquez volcanics? Different from Vasquez rocks

[@davidkaplan2745]

Welcome to Carlsbad, we hope you like our volcano!

[@geologicallyspeaking]

I've got family here in Carlsbad! Love Carlsbad and your volcano.

[@glendabarton45barton48]

This is great. Hardly ever hear about volcanos in Southern California. I'm collecting facts about California, superlatives (biggest trees,oldest trees, tallest trees that sort of thing) maybe for a book? I read recently there are 20 volcanoes in California,some active, including the second biggest stratovolcano in the U.S. (after Yellowstone), Long Valley Caldera. Correct me if I'm wrong Just read about many eruptions millions of years ago in Clear Lake near where I live....considered somewhat recent. Clear Lake is the oldest lake on the continent. The volcanic field here in Sonoma and Lake Counties is the biggest or at least one of the biggest geothermal fields in the world,magma still beneath and steam fissures, a smaller copy of Old Faithful and a Petrified Forest of old giant redwoods one of the finest examples in the world. Once I took a field geology class all the way up the San Andreas fault,mind-blowing all the way to where it goes on the ocean around Bodega Bay. And the first seismograph in California at San Juan Bautista Mission with the jagged lines of the 1906 earthquake. Fascinating! We live in a unique and beautiful State!

[@geologicallyspeaking]

Very interesting! I'm unfamiliar with that area, but yes, I whole-heartedly agree that we live in a wonderful state, geologically speaking. 😉

[@xavierares8464]

Out here where i live in diamond bar /pomona ca there is also an old volcano on the elephant hill site you should come do a video....Vee and Gary re: Pomona. South of Pudding stone reservoir (aka Frank G. Bonelli regional park) is Elephant Hill. A volcano located just east of the I-57 by the railroad tracks. W.Mission road cuts right through the center of it, you can see the cone shape from inside of the volcano as Mission turns into Diamond Bar. Gypsum can be found in the road cut. This is the epicenter that cause the pudding stone to rise and create the hills and formation to the north of the I-10. Info came from Geology class 1977.

[@geologicallyspeaking]

Thanks for the tip and information Xavier. I'll have to check that out!

[@MrJonnywanderer]

This is great! Have you ever done the cliffs at Dana point harbor?

[@geologicallyspeaking]

Ah yes the San Onofre Breccia of the Dana Point Headlands, one of my favorite formations. It's definitely on my list.

[@glendabarton45barton48]

There's the remnants of a volcano turned inside out in the Berkeley of Oakland Hills. I never knew that. Considered a rare glimpse of an inside-out volcano. I'm not sure what they mean by that. Berkeley OR Oakland Hills. I want to take geology again!

[@geologicallyspeaking]

Awesome. There has to be a geological paper written on it!

[@glendabarton45barton48]

@@geologicallyspeaking I just found out about it! Also I never knew about the shell mounds.

[@Zyworski]

Why does basalt cool into more linear columns like crystals, is it the silicon content or something else? The dacite looks much different than the basalts, andesites, and rhyolite that I see in the PNW, it is white and there is no white rocks anywhere around Eastern Washington.

[@atomdent]

Very Cool!

[@johnkmatsch]

there are some amazing fossils at very bottom of Torrey Pines cliffs at low tide, south of the state park parking lot. The San Diego coast has risen and receded numerous times. There are beach stones all over. be cool to get some information on that.

[@geologicallyspeaking]

I made a video on Torrey Pines! Check my channel.

[@johnhubbard6262]

There was a couple mines located there, wonder what they were mining.

[@SCW1060]

North America crossed over the East Pacific ruse which may have supplied the magma but this is the most plausible source of that magma

[@bradriney919]

Just south of the beach access staircase at South Carlsbad State Beach, exposed within the sea cliffs is a series of latest Oligocene non marine sandstones and siltstones containing a grey layer of bentonite. I've alway wondered if that ash puff that weathered into that bentonite originated from from the calaveras volcano. If it is, the date of the bentonite would be 28 to 30 million years as evidenced from the late Arikarrean age vertebrate fauna found within the surrounding sandstones above and below that bentonite. I'm unaware of any radiometric dates on either. Any thoughts on this?

[@MegaTriumph1]

I would like to see a live example of columns forum in a almost liquid state to create such a column. Do you have one.

[@geologicallyspeaking]

So would I, but these typically form well-underground hidden from our view. It's only once the layers above them have eroded away that we are blessed to see their grandeur.

[@inyobill]

I had no idea that we had such nice columnar basalt in San Diego County ^^. Oh. Not basalt. I learned something. Now my head hurts, thanks a ton.

[@ManambeLavaka]

Ohhh do Dictionary Hill please!

[@wfweingold8675]

Excellent video! 👍Did this volcanic activity occur at the same time as Cowles Mountain?

[@JeffreyPhillips]

Cool channel bro

[@geologicallyspeaking]

Thanks!

[@curtiscroulet8715]

Maybe you said and I missed it. Has this volcano been mined for aggregate? That's not a "crater" that we see -- is it? Why are the dacite columns exposed?

[@geologicallyspeaking]

You are correct. It was quarried in the past. In fact, most of the fill to make the dam came from the volcanic plug!

[@curtiscroulet8715]

@@geologicallyspeaking Thank you for confirming one of my occasionally correct hypotheses about geological features. :) This isn't the place for my following comment, but there really isn't a good place. I live in Anza (more exactly, Terwilliger), in interior Riverside Co., CA. I've never seen a study or authoritative book or paper about our region. Most books just throw it into the general province of Peninsular Ranges, and then they go on to describe the mountain ranges and batholith. I once read that the elevated, rolling terrain of Anza, Terwilliger, and Parks (Lake Riverside Estates) valleys was once continuous with the extensive peneplain surface of southern San Diego Co., which continues into northern Baja C. Methinks there's a PhD dissertation in our area awaiting a geology student. One specific feature I'd like to draw your attention to is Cahuilla Mountain. The mountain is notable for the sheer "granite" outcrops exposed on its south side. This feature is readily visible to the north from Hwy 371, and it's even visible from Temecula from elevated locations. It appears to me -- just my uninformed opinion -- that the mountain once presented a generally rounded profile, but that the south side of the mountain actually collapsed, exposing the mountain's "granite" core. It looks to me like the terrain between Hwy 371 and the mountain is a large landslide. But I don't know. It'd be nice if some geologist would take a look at it.

[@joseangeltorresespinosa7997]

Es un buen video y su contenido geológico felicidades, observe en una toma del video que se encontró unas estructuras arredondeadas, puedo deducir que se trata de pillolavas, originadas en un ambiente marino, hoy en día se encuentran erosionadas, así también creo que ese volcán tuvo varias erupciones a través del tiempo por tener varios tipos de rocas felsicas con algunos rápidos enfremientos de la lava volcánica, un buen saludo desde México DF.

[@geologicallyspeaking]

¡Saludos desde el sur de California! Sí, debo admitir que pensé que esas formaciones también eran almohadas de lava, pero por lo que he leído, se trata de patrones de meteorización esferoidal.

[@masatosway4558]

I love your videos! What book are you referencing?

[@inyobill]

20:26: Pretty apparent quarry cut into the hill

[@markvanleeuwen6678]

Driven by a 1000 times. Never hiked there.

[@geologicallyspeaking]

You gotta make time and do it! Relatively easy hike to the plug. I'd recommend later afternoon as the lighting is better at the columns.

[@dontask8979]

Its a baby Devil's Tower. It just needs a few million years.

[@geologicallyspeaking]

Hahaha! Right?

[@amariebeaubien]

I'm curious as to how old the pegmatite near Pala is?

[@geologicallyspeaking]

Shooting from the hip here, but that's part of the Peninsular Range batholith, so around 100 million years old (+or- 20 million years).

[@johnbollenbacher6715]

These basalt columns cooled from the bottom? I would’ve thought they would’ve cooled from the top.

[@geologicallyspeaking]

I added an annotation on the screen when I said "from the bottom up" that it could also cool from the top, down. You're right, in this instance since it was a volcanic plug, the cooling and subsequent jointing probably began from the top down; however, if columns occur within a lava flow over cool country rock, the cooling and subsequent jointing could occur from the bottom, up. Also, surprisingly this isn't basalt! It's dacite! Similar composition to granodiorite, however since it cool relatively quickly (compared to a magma chamber miles below the surface), the mineral grain sizes are imperceptible to the unaided eye.

[@jamiedbg51]

Mt. Lassen is Dacite as well. The blue rock to the right of the unconformity looks like the Paloma Schist.

[@seeharvester]

I wonder what those ancient pictographs mean?

[@IBRAKEFORBEDROCK]

I would think that lake would be crystal clear with all the environmental regulations in California

[@dickey5556]

Just built a pool right there a couple months ago. I am not allowed to fish in the lake .

[@davidkepke1435]

I see why they named it Calavera Hills. Calavera is Spanish for skeleton. Some of those little round rocks look like human skulls. Never knew about this place before. Been to Carlsbad quite a few times.

[@davedavis5809]

that red mineralized rock with clasts of rounded 4iver rock looks alot like what ive been working on... I would like to see what a sample of that compared to the red Rock in the pinnacles near Paso Robles.the same material on The western side of mt whitney.... compared to the red stone in the San Juan mountains in Colorado I would like to see that all listed out I would bet there's very little difference and the same trace minerals what I'm saying is they're all connected and that's probably not a volcano igneous yes volcanic no at least not in the way that you think

[@jonnelson9059]

crazy eocene

[@jonnelson9059]

oops myocene...lol

[@geologicallyspeaking]

@@jonnelson9059 The Miocene is crazy, the Eocene is crazy....it's ALL crazy!!

[@virgo714]

what type of volcano is that one? Also, its safe to say its an extinct volcano right now

[@ralphhancock7449]

How can the magma cool from the bottom up?

[@geologicallyspeaking]

Great question Ralph and I added an annotation to correct what I said about this particular volcanic plug which most likely cooled from the top down. However, think of a thick lava-flow flowing over a landscape, the bottom of the lava flow is in contact with cool ground and, in that instance, the lava could cool from, not only from top down, but also, from the bottom, up.

[@ralphhancock7449]

@@geologicallyspeaking Thanks. I recall my geology teacher talking about columnar joints forming in a lava layer that had 'wet feet'. I assumed that meant 'wet' like in soldering - hot liquid state melt. When I gingerly approached the teacher about that, she indicated that it had something to do with a wet steemy footing. I didn't press the issue. I just figured she didn't know about the soldering/welding terminology. I didn't want to embarras her in front of the class. But I've never bothered to check up on the assumtion I made. We here in Oregon have a lot of lava flows sitting on top of pillow lava layers, so it could be a matter of lava flowing into shallow sea water - thus the 'wet feet'.

[@alanbelasco2931]

Did you see any evidence of pyroclastic flows? I’m guessing not because you didn’t mention it. Thanks for the tour