Overview of Geologic Structures Part 1: Rock Deformation, Stress and Strain

Now that we've briefly gone over the history of the Earth, it's time to look at some different geologic structures that span all those eons. This will require gaining an understanding of rock deformation. We need to discuss the terms stress and strain, as well as Young's modulus, which describes their relationship. From there we can describe the different types of rock deformation. Let's go!
Script by Jared Matteucci
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[@MM-vs2et]

I can't believe that the best description of myself is a geological term in 4:00

[@glennpearson9348]

Nice recap of my materials science course in college. Then, a bit later, spending hours in the Civil Engineering Lab stretching and crunching things with the hydraulic press. Thanks for the trip down memory lane, Professor Dave. Excellent presentation, as always.

[@jbirdmax]

Just a couple weeks ago my family and I felt a huge thump throughout our property. After some investigation we discovered that our driveway had nearly exploded. There’s a huge tree nearby that had its roots running under our driveway and put the 8inch concrete slab under so much stress that it finally gave way to that stress and exploded and shattered a 15 foot section. Incredible.

[@TheReaverOfDarkness]

The plant used hydraulic pressure to do that.

[@MisterItchy]

Wow! Glad nobody was hurt. Sounds expensive, though!

[@rporta]

damn

[@brassman7599]

This is a cool one to explain. The most likely cause of the actual failure of the material was due to thermal expansion. Concrete takes compression loads well but cannot handle tensile forces and falls apart easily (cracks). the roots growing under the concrete imparted a tensile force on the concrete. The slow growth of the roots allowed the material to deform slowly until it reached the limit of the tensile strength of the material. Rapid temperature change such as what happens when the sun rises and sets causes thermal expansion or contraction in the material. If the material was already at it's stress limit then the rapid change of temperature importing additional tensile forces would cause catastrophic failure. I've seen something similar happen in several quarries after recent removal of overburden. The newly exposed rock, no longer subjected to heavy compression starts to exfoliate. Often around noon to early afternoon when daytime heat was at its height I would witness numerous literal explosions of rock. It's quite the experience to just be walking along and suddenly the rocks themselves start exploding.

[@mauski24]

I live 20 minutes from the badlands in western North Dakota and being able to see all the different types of rock layers, ash layers from past Yellowstone eruptions is so beautiful and amazing!

[@fatimahaidari]

I love You professor. I am learning italian with your lessons and math also. Thank you so much for getting time to help us.

[@anasal-qaisi6392]

Started with history of earth part 1, I can’t stop now, wish I knew your channel long before The best content, best language, very good audio quality, and super informative pictures, videos and charts. 10/10 Wish you all the best

[@subductionzone]

When arguing with creationists that claim that rocks cannot deform without breaking I have a favorite picture of two trilobites at ninety degrees to each other. one had been compressed lengthwise, the other is of course compressed on its sides making it longer. And structural geologists frequently use fossils as strain markers. They do not care what species they are, well some species are preferred since they demonstrate strain so well. Various bivalves act as natural strain markers.

[@richardcolton1009]

i gotta say if ur really interested in any of the topics Dave delves into this is like instant knowledge--he is the best!

[@jonathon5075]

I haven't engaged with anything geology related since middle school. Thanks for providing this approachable resource for someone trying to learn the basics from basically scratch

[@qzh00k]

Salt domes are a great example of the fluid dynamics involved in geological time. What we do with them is another story and an industry in itself

[@lewas91]

Professor Dave, you're a gold mine of knowledge, thank you for your hard work. These contents helped me a lot many times in my studies.

[@temperatemix8268]

Great presentation and in general correct. One nugget to pick up on is pressure does not always increase in with depth. It’s a function of fluid fill as well. A good example is hydrocarbons causing overpressure or a really good acquirer causing under pressure in a rock formation

[@frufrujabenderps]

1:38 The Illustration in this frame is incredible. The form of the earth is so well emphasized by using a single point for the flow to emerge. This would make a good tech-death metal album cover.

[@adigozelov-enjoyer]

My favorite subject! Keep it up, Dave!

[@nicholas1173]

Been loving the geology series so far. Very nice >:]

[@GARYTHDawson]

Thanks Professor Dave, been on a derp trip watching flerfs and science deniers, this cleansed me.

[@GodlessGranny]

Thanks for the geography course. I failed Steve Bauman's initial test to understand his courses. So I'm taking yours to get enough base knowledge to understand his.

[@urbashiphukan1155]

Nice explanation Thank u so much sir..lots of love from India 🇮🇳

[@brassman7599]

As an introduction to these topics it was ok. most of the topics presented here require at least a basic understanding of thermodynamics as well as a number of other subject to really understand how they work. I'm hoping further videos on geology do more than just scratch the surface. I know it's not Dave's specialty so it's interesting to see how a teacher with a different focus tackles the subject matter.

[@kiwi_2_official]

how much work are you putting into these videos? it feels like every time i go on youtube there's a new video from you and each time it's a good (and long) one that half of the time is in a new series / starts a new series.

[@deepquake9]

Thank you Dave!

[@jessicadeines]

During certain time frames it seems like geological activities can speed up or slow down. Can they also reverse direction?

[@planetearth2249]

I guess it could be said that this overview is pretty rock-solid.

[@chasezobl4248]

YES, A GEOLOGY VIDEO!!!!!!!!

[@GodlessGranny]

Thanks!

[@fakhrulnawawi9681]

Thanks very much

[@pridelander06]

I realize the main topic of this video/series is geology, but the concepts of stress/strain and elastic/plastic deformation also form an excellent introduction to materials science.

[@gonzalosuarez7461]

Yeah, structural geology relies in his bases heavily on rheology

[@chair547]

Is there an olds modulus

[@jokaerojim1666]

Hey Dave, could you recommend me a good geology introduction book please? 🙉

[@donchristie420]

This helps toward my debates with a retired engineer YEC (he thinks Noah’s flood did it)about the folded rocks in the Grand Canyon, thanks

[@MaryAnnNytowl]

So, competence in rocks is akin to stubbornness, eh? Then I'm really competent! LMAO! 😄😄❤❤ Wow, Professor D, you're almost at TWO million subs! We just saw Anton reach one million, and that's pretty great for s science communicator, but you're about to DOUBLE it! I hope you have a special when you hit that mark! (Edited for clarity)

[@marvin.marciano]

Hello Dave, i can see some videos on this playlist are private. I wonder what happened to them

[@ProfessorDaveExplains]

They will all be released around one per week!

[@kamion53]

Thanks, I needed this video after having seen one this week by Mattia Peel Powellina in which he without even blicking claims all those huge faults in mountain ranges were caused by THA FLOOD.

[@50_foot_punch99]

this and forehead fables are the two things I watch constantly

[@TheN0odles]

I experience sheer stress on a daily basis.

[@sciencenerd7639]

wow!

[@brianh870]

Love your videos. One quick correction, at 2:44, you say, "If an object experiences sufficient stress to cause deformation... it undergoes strain". Stress doesn't have to build up to get to a strain. Every stress will cause a strain, no matter how small. The strain just may not be visible on the macro scale. If you look at the graph of Young's Modulus at 3:22, you'll see the graph starts out linear and passes through the origin of 0 stress and 0 strain.

[@gordtvradio3465]

No, the video is correct. Stress causes strain, which is synonymous with deformation

[@brianh870]

@@gordtvradio3465 I’m not sure you understood my reply. I wasn’t saying that stress doesn’t cause strain, I was saying that you don’t need “sufficient stress” to cause a strain. Every stress, no matter how small, causes strain.

[@gordtvradio3465]

@@brianh870 In that case, you are nitpicking big time

[@brianh870]

@@gordtvradio3465 I disagree. This was drilled into us in my mechanics of materials class. Every stress, no matter how small, causes a strain in the material. I wasn't trying to nit-pick, I was trying to add more information into the discussion. That's all.

[@gordtvradio3465]

@@brianh870 In that case, good on you!

[@mikhailquashie9899]

New video upload soon? @ProfessorDave

[@MooCowKris]

I freaking love science

[@frufrujabenderps]

4:08 there are currently no known jokes about incompetent rocks.

[@40g33k]

"But how rock become man?" - Some Flerfer/YEC.

[@columnarbasalt4677]

hell yeah

[@otisbrown420]

Need some help crystals..do they have anything in them? Anything

[@wesleyverity7310]

Slope is the most important concept in all of learning. Change my mind

[@alanthompson8515]

I'll level with you. That is flat out ridiculous!

[@inexpl]

Who made the end music?!!!

[@ProfessorDaveExplains]

me and my friend

[@inexpl]

@@ProfessorDaveExplains came here for the science, left with this wholesome knowledge.

[@soldierbhiya6294]

Your intro is nostalgia

[@backstreetfan2887]

hooray, geology!

[@Azadi.Iran1402]

❤❤❤

[@-JA-]

😊👍

[@cbzc1035]

Keep up the great work educating the masses. Unfortunately when it comes to changing people's dogmatic ancient ways of thinking its going to take a lot more than just education. You can't teach a willingness to learn if their life's meaning is contradicted by what educators teach (any anti science organization) Critical reasoning should be taught in elementary and high-school.

[@cbzc1035]

Minerals Marie!

[@kaantax8666]

oh god am i the only one who read the thumbnail's title as "young Morbius" ?

[@fartpants90]

Faults?? That thar means gold in them thar hills yeeeeehaw

[@MisterItchy]

Imagine thinking that rocks are hard!

[@ProfessorDaveExplains]

Weirdest troll ever.

[@lorditsprobingtime6668]

Matt Powel needs to watch this. That clown has some very ... odd and different beliefs about this subject.

[@sooraj8093]

Heii ✨

[@alifrahman5430]

Hi dave, I watched your debate with flat earth dave, in that debate he asked you that why the sun don't pull the moons of the planetsto which you responded that the g.f between planet and the moon would be greater than that of the sun and the moon, since g.f is inversely proportional to the distance between two objects. You were incorrect in that. After calculations, the g.f between sun and the moon is 4.3 × 10^20 N and the g.f between earth and the moon is 2.0 × 10^20 N. You can calculate it yourself. We can see that g.f between sun and the moon is greater than that of earth and moon. So please explain to me that why the sun doesn't pull the moon. I'm not a flat earther nor a gravity denier. Thank you.

[@ProfessorDaveExplains]

Did you notice that the moon does indeed orbit the sun while orbiting the earth?

[@alifrahman5430]

@@ProfessorDaveExplains oh ok. Both orbit the sun while exerting gravitational force on each other. Thanks.

[@alifrahman5430]

@@ProfessorDaveExplains also can you explain how zero gravity planes work or make a video on it.?

[@ProfessorDaveExplains]

Well it’s not zero gravity, it’s just freefall. Same with orbit too, there’s gravity but everything is in constant free fall.

[@alifrahman5430]

@@ProfessorDaveExplains is this the same phenomenon happens in space station.

[@tylersamuels4438]

I know this is the wrong vid, but I just listened to the first 10 seconds of JLP speak and I need somewhere to express how eye wideningly hilarious that was 🤣. He straight up said "I grew up on a plantation under Jim Crow laws and we didn't have any of this so called 'race problem'". That brother is so far gone

[@knightclan4]

Uniformitarianistism versus Catastrophism. The real question is how catastrophic global floods occured to produce 6 main sedimentary strata mega-sequences. Scripture claims just one global flood. C14 in coal and diamonds. Human relics inside coal. Bent strata to the extent that uniformitarianistism can't explain. (Don't say heat and pressure, because that would cause metamorphosis) If I were you, I suggest you start trusting God's Word and put your faith in Jesus

[@henry7486]

Hey Professor Dave Explains, Did you know that you look like Jesus himself? Would be keen to know.