Overview of Geologic Structures Part 2: Faults and Folds

We just learned about the different types of rock deformation, so now let's get a closer look at some more specific structures. First we have faults, which can be normal, reverse, and strike-slip or reverse faults. We should also take a look at folds, which can be synform or antiform, and syncline or anticline. What do all these terms mean?! I'll show you!
Script by Jared Matteucci
Watch the whole Geology playlist: bit.ly/ProfDaveGeo
Mathematics Tutorials: bit.ly/ProfDave...
Classical Physics Tutorials: bit.ly/ProfDave...
General Chemistry Tutorials: bit.ly/ProfDave...
Biology Tutorials: bit.ly/ProfDaveBio
Microbiology Tutorials: bit.ly/ProfDave...
Botany Tutorials: bit.ly/ProfDave...
Zoology Tutorials: bit.ly/ProfDaveZoo
EMAIL► [e-mail]
PATREON► / professordaveexplains
Check out "Is This Wi-Fi Organic?", my book on disarming pseudoscience!
Amazon: amzn.to/2HtNpVH
Bookshop: bit.ly/39cKADM
Barnes and Noble: bit.ly/3pUjmrn
Book Depository: bit.ly/3aOVDlT

[@philipliao4006]

Likely won't be taking any class related to this topic, but always love to learn

[@sciencenerd7639]

very gneiss

[@LLEvarts]

Of quartz somebody had to start with the bad geology puns.

[@rickkwitkoski1976]

@@LLEvarts Shale I continue? They are quite marbleous actually. Just don't take any for granite. Your CORE assumptions may be at fault!

[@lernaeanhydra425]

kzbin.info/www/bejne/gIG4moisoZang9U

[@nugboy420]

Gneiss cleavage…? -_-

[@GeoGolfer]

@@rickkwitkoski1976 Was gonna make a pun with the mineral cummingtonite but it strikes me as a dip in value.

[@lucyoneill2078]

praying professor dave videos come in clutch for my geo final tmr

[@sx5047]

The only heartwarming KZbinr out there with real critical thinking. Congratulations on your 2 million subscribers man!

[@roypatton1707]

Ahhhh! It's so good to hear Geology again. I miss it.

[@qutopyo4428]

I'm not even close to needing to learn about this, but it can't hurt

[@thjacobi2]

Great video Professor Dave, normally it takes a full semester to explain this. Would love to see geophysics covered too!

[@Hammer2000]

As a fantasy worldbuilder, things like this help me immensely, knowing the reasoning behind structures helps in making realistic environments, or having an idea about the science gives you a baseline to play with when making them fantastic. Thanks so much!

[@rekkwaffle7668]

Yes! I'm not the only worldbuilder here for that reason! Lol amazing

[@TescoMealdeal32]

Congratulations on hitting 2 million subscribers!!

[@gooseart2222]

I can't believe it. Dave Grohl is such a talented musician and still has the time and intelligence to teach us about everything on KZbin!

[@roypatton1707]

I get that you're joking, and it is a funny comment, but did you know that Brian May, guitarist for Queen, has a PhD in Astrophysics?

[@gooseart2222]

@@roypatton1707 Yes, actually I discovered it in one of the strangest ways possible: A couple of years ago I was reading an article about the zodiacal light and when I looked at the references from the article his name was there haha.

[@trashAndNoStar]

@@gooseart2222 must've been quite bizarre to discover that randomly 😁. I read an article on that topic ages ago, the Offsprings singer also has a degree in Biology or something like that.

[@acommunistdwarf]

This is a very exciting topic to learn about, thanks for making this so accessible Dave. I find it amusing how many of the terms, rock formations and types of minerals and rocks I've learned by playing Dwarf Fortress, I'm following this together with the walkthrough of the periodic table to compare how the game distributes some of the metal ores.

[@user-bx3fz8pj8n]

Excellent lecture! As I'm one geology student I'm gain good explanation!

[@stevon2000]

Congratulations on 2mil man! I’ve always loved your normal style teaching videos but the debunking videos are so damn funny.

[@rickkwitkoski1976]

PLUS you can get some good ideas about what to say when you encounter numpties yourself.

[@ashleygilliam6205]

Not only was this a great summary of faults and deformation but you pronounced Appa ”latch” ian correctly! Yay! Will always appreciate any videos about geology, geomorphology, geoarchaeology or archaeology. 🙂 love your content and appreciate all the hard work you do!

[@GeoGolfer]

geoarcheology? you mean paleontology?

[@ashleygilliam6205]

@@GeoGolfer geoarchaeology. Paleontology and geoarchaeology are different disciplines.

[@GeoGolfer]

@@ashleygilliam6205 I know, I'm a geologist. This video was not about archeological side of earth sciences and many don't understand the difference between archeology and paleontology. Obviously wasn't your case. My bad.

[@ashleygilliam6205]

@@GeoGolfer True. That's why I'm grateful for Dave delving into these topics. Just to reiterate, I will always appreciate any videos he makes or will hopefully make about geology, geomorphology, geoarchaeology or archaeology, since those areas are important to me and my experience in the field. The more videos he makes about these disciplines and how they are interrelated the better. Archaeology is definitely not paleontology, folks. ;)

[@iliyanovslounge]

2M Subscribers. Yahooo!

[@9fmradisapratama]

3m soon

[@abenezerwondewosen]

does the earth's crust have that fault?

[@nohbuddy1]

Plunging Folds is a good band name

[@muzikhed]

Nicely explained, very interesting, Cheers.

[@vintinoo1924]

Another great Vid! Didn’t even know I had an interest in this topic until I started watching your geology stuff. Keep up the educational stuff!

[@ebonkrieg]

Good Stuff!

[@Askify]

My Transcript notes of the video 00:00 we just learned about the different types of rock deformation but there are two very important structures pertaining to this concept that must be discussed 00:15 in detail those being faults and folds faulting is the main type of brittle deformation in rocks faults are classified based on the type of deformation that creates them normal faults are caused by extension 00:30 reverse faults by compression and strike slip or transverse faults by shearing normal and reverse faults are called dip slip faults because fault motion or slip is parallel to the false dip this is in contrast with strike slip 00:49 faults where slip is perpendicular to the dip in geology dip refers to the direction that the fault plane is inclined to conceptualize this imagine that you pour a cup of water onto an inclined 01:04 surface the direction that the water flows is the dip which has two components an azimuth representing a horizontal direction and an angle representing the steepness of the plane 01:18 in any dip slip fault there is a hanging wall and a foot wall if you imagine drilling a tunnel longitudinally through the fault when standing in this tunnel you would be standing on the foot wall and the hanging wall would be above you 01:33 in reverse faults the hanging wall moves upward and in normal faults it moves downward reverse faults primarily form in areas where the tectonic plates are converging like along subduction zones and 01:47 continent continent collisions there are also areas where the plates are converging at an angle these transpressional faults experience both reverse and strike slip faulting a fault with both dip slip and strike 02:03 slip motion is called an oblique fault an example of this is the san andreas fault here the pacific and north american plates are converging at about a 10 degree angle 02:16 though predominantly a strike-slip fault it is also slightly compressional as is evidenced by the coastal mountain ranges of california normal faults are most common where the plates are moving apart and the crust is 02:31 being stretched this is currently occurring in east africa the basin and range province of north america and at the center of every ocean basin in the world as the crust thins during extension its 02:44 weight above the underlying mantle is reduced and spread out over a larger surface area this causes the crust to bob up in a process called isostatic adjustment or more specifically isostatic rebound 03:01 it's like walking off a boat when your weight is removed the boat bobs upward and rises in the water get back in and the boat bobs down in response to your weight back to the geological case the crust is 03:15 analogous to the boat and the mantle is analogous to the water with the crust bobbing up and down in response to the thickening and thinning of the crust the same thing occurs in areas that are experiencing compression the 03:29 compressional forces thicken and shorten the crust causing subsidence because the now heavier crust will sink into the mantle this is what leads to the development of four land basins or large areas of 03:43 depressed land located adjacent to large mountain ranges the weight of the mountain pushes the crust down into the mantle not only beneath it but also adjacent to it and it is these adjacent lowlands that sink 03:58 below sea level during isostatic adjustment which in this case is called subsidence basin subsidence is what makes the formation of ultra thick sedimentary deposits possible 04:12 for example as much as 10 000 feet of sediment accumulated in the catskill four land basin over a period of only about 20 million years during the upper devonian period this sediment was shed from the now 04:26 eroded acadian mountains that existed along the eastern seaboard subsiding forland basins like this have fostered deposition of some of the largest sedimentary formations in the world 04:39 in some areas compressional forces cause rocks to become folded like a car that gets crumpled during an accident folding occurs when a rock is being compressed and the temperature and pressure are just high enough for plastic deformation 04:53 to occur folds are classified based on their geometry and stratigraphy or arrangement of strata folds that are concave up are called sin forms and folds that are concave down 05:08 are called anti-forms when layered rocks are folded into a sin form the youngest rocks will usually be at the hinge of the fold which is similar to the local maximum or minimum of a parabolic function To get the full transcript of the video with PDF screenshot notes - Try Askify chrome extension

[@chessematics]

You are such a lord!

[@FriedrichHerschel]

@@chessematics My money is on bot.

[@chessematics]

@@FriedrichHerschel yeah i just forgot about the fact that we have bots on KZbin nowadays

[@Askify]

@@chessematics I am not a bot

[@Askify]

@@FriedrichHerschel :(

[@triadmad]

Anyone that travels I-68 in Maryland is familiar with the Sidling Hill Syncline, located at mile marker 74. When that road cut was completed in the 1980s, geology professors at all the nearby colleges about wet themselves in excitement, because it's a perfect example for their students to study.

[@glennpearson9348]

I drive by Sideling Hill, too. I think it's what is pictured at 9:20 in the video, but I can't be certain. An impressive example of a syncline. I think it's too bad they shut down the visitor's center.

[@trym54]

Do a video about what you think about free will! Would be very interesting

[@kristoferstrauss6475]

well, asuming he blocked comments about topics he is wrong about, he is clearly not supporting that.

[@trym54]

What topics are you referring to?

[@9fmradisapratama]

It's pretty much subjective philosophical argument. But I believe average scientists agree with determinism. As well as predicted chaos.

[@trym54]

Im not really sure if I agree that it is subjective philosophy. I think determinism (with the exception of quantum randomness) can be proven beyond reasonable doubt, at least to some extent

[@9fmradisapratama]

I will personally remain agnostic about predictive chaos or free will. I'll wait for the people to continue uncover things until they see the results. Unfortunately, some people or media will try to assume you if you think you like Einstein's determinism, then you're completely against Stephen Hawking or Michio Kaku and the reverse, if you like scientists who like the concept of free will like Hawking, then you must dislike determinism. But this doesn't mean I don't have any opinion about them as I think both concepts are quite interesting to learn and have their own standpoints.

[@OhmVibe]

8:57 -> 8:38

[@ispylugaw9775]

Im not a geology student but this thing is interesting

[@leviforbes301]

#1 number 1 science Man!

[@turbobrain1342]

How is it that you know so much more about Geology than Kent Hovind?? After all, Kent taught Geology for 15 years.

[@rickkwitkoski1976]

🤣🤣🤣🤣🤣🤣

[@turbobrain1342]

@Emilia he says that he taught Geology 15 years. He has 0 training. He teaches that continental drift was 45 mph, rocks cannot bend and all of the rock layers went down at the same instant.

[@turbobrain1342]

@@rikeshshah3226 So, I assume that, with a script prewritten, you could do just as well as Dave, or even better?? Let's try it on a live stream? I assume that you did not watch Dave debate David Weiss??

[@FirstnameLastname-kj9oi]

I start getting confused by the 5 minute mark and now I'm completely lost😢

[@Killbayne]

"when a rock has cleavage" is a line i didnt expect

[@adhiezulfikar]

I was majored in Geology and turned into Digital Marketer 🤣 This video gave me PTSD somehow hahha

[@fiercemonkey1]

Oh professor Dave! once ur done with the earth can can you do a in-depth dive like this on some of the planets in our solar system? Like the black ices (phase 4 and above) in the ice giants, the metallic hydrogen in Jupiter and Saturn, and the ever renewing Venusian crust? Professor I think your take on it would be epic! Your really good and cleanly explaining complex topics with a high degree of justified specificity while not being dull, long winded or full of superfluous anecdotes. Thank you sir o7 please keep up the quality hard work! 😊👍

[@secularidiot9052]

I'm pretty sure he already did an indepth dive into each of the planets on his astronomy playlist.

[@9fmradisapratama]

I've been a fan of "hot ice" I mean there's a place where that state occurs such as in Neptune's mantle or outer core.

[@joshvoigt5543]

Idk if you've heard of "new physics by Joseph George" on KZbin but I definitely think you should check him out. He thinks thag eisteins theory of relativity is wrong because it doesn't calculate "aether" lol

[@desmond3828]

It’s time for immunology again!

[@pouinkimir]

oh wow, why so many dislikes on this video?

[@ProfessorDaveExplains]

was probably released immediately after a debunk that angered a lot of brainwashed idiots

[@cookieman2028]

Can you debunk passerine birds please?

[@-JA-]

👏👍

[@theartsig]

I think "subsidence" is pronounced with a long 'i'.

[@GeoGolfer]

Both are used in geology.

[@willhayes3095]

Professor Dave is there a topic concerning Spiral Rotation in relation to Spacetime please? Example being that one can draw a spiral dimension as the upper and lowerbounds of both the electric and magnetic field peaks and troughs as they travel in a direction...So Spacetime and relative "spiral rotational clock" frequencies...I am trying to find something about this. Thanks

[@oliver1707]

Bro sounds a bit like eminem

[@bludaizee24]

Thank you so much for your videos David! I love learning new things! I'm trying to figure out how the pretty rocks in my yard were formed. Some are plain and bland looking. Others have quartz in them. Some have pink and black stripes, some look like pink granite. It's quite the selection! Lol My property in in Northern Alberta. I live between Grande Prairie and Dawson Creek.

[@waelfadlallah8939]

That's a well elaborate video thank you

[@alibadra2386]

👏👏👏👏

[@Deus_Vult389]

How the hell did you manage an hour and a half with Jesse Lee Peterson? Kudos to you for that.

[@kvgiris]

clevage

[@masoudrahimi3696]

Rest of videos in this playlist are hidden. I can’t watch them

[@chrisangel6833]

sick video bro

[@najatvlog2796]

🌿❤️🌹👍💋🌿🌿🌿🌿🌿🌿🌿🌿🌿

[@GodlessGranny]

Nice! lol

[@SpacePirateFromSpace]

What about when the two pieces are in a fault where they’re moving in the same direction, but one is moving faster than the other?

[@gordtvradio3465]

It’s all about relative motion. Many faults are moving along a similar azimuth with differences in velocity creating the relative motion that causes the faulting

[@GeoGolfer]

Like all motion, it is always relative to a point of observation. In structural geology, it is assumed to be wrt the other side of the structure.

[@Nikson2981]

yo more geology woo

[@mr.commonsense]

How is Science Jesus doing?

[@Manimmut]

Can you Talk about gaia?

[@9fmradisapratama]

Gaia is like Goop but with quantum mysticism. I think if you watch professor Dave's Quantum Mysticism video, it's pretty much self explanatory.

[@Manimmut]

@@9fmradisapratama the Satellite?

[@9fmradisapratama]

Oops. Apologizes. I thought you meant that channel named Gaia. If you're unfamiliar, there's a video called "Galaxy brain garbage of Gaia".

[@Manimmut]

@@9fmradisapratama is it about the Channel or Satellite?

[@9fmradisapratama]

A channel. Not satellite.

[@Azadi.Iran1402]

❤❤❤🙏🙏🙏🙏

[@Cryptid.Couture]

my dip slip don't jiggle jiggle. it folds.

[@bestman2670]

This man is so knowledgeable on a vast number of subjects! I wouldn't be surprised if his IQ is at least 120.

[@jazmoko]

Wow...Dave underestimated James Tour

[@ProfessorDaveExplains]

Um, did I? Or did he underestimate me?

[@bluespark01]

@@ProfessorDaveExplains I just wanted to let you know, your awesome!

[@9fmradisapratama]

Don't try it!

[@kylejf2108]

Filling in the gaps, in more ways than one.

[@warot359]

Why does the tectonic plates keep moving? Why they haven't reached an equilibrium state after billions of years of earth formation?

[@Tomago9387]

So long as the earth has an active, heated core it will continue to shift.

[@jeffsmith9503]

convection currents keep moving them. convenction currents are from earths core. earths core is still hot. hot means to move

[@gordtvradio3465]

It’s actually mainly radioactive heat within the mantle that powers plate tectonics, about 70%, compared to 30% for primordial heat.