Igneous Rock Classification & How to Use The QAPF Diagram- Igneous Petrology #1 | GEO GIRL

[@dandur1649]

I watched a lot of petrological/geological videos out there but nothing matches the quality of your channel has, thank you so much!

[@GEOGIRL]

Oh my gosh, this made my day! Thank you so much, I am so glad you find my videos helpful! :D

[@alanbelasco2931]

“What the heck does that mean?” is my favorite Rachel expression. It means an explanation in plain English is coming up! Thank you

[@GEOGIRL]

Hahaha this comment just made me laugh out loud because I didn't realize I do that but you are totally right I do LOL! I am so glad you enjoy the plain english explanations (or at least my attempt at explaining things more clearly haha) ;)

[@alanbelasco2931]

@@GEOGIRL Please don't stop using that phrase. It's awesome!

[@firstnamelastname9918]

LMAO!! I love your answer!!! ❤ "It means an explanation in plain English is coming up!"

[@KerriEverlasting]

I'm following the feldspar trail armed with the ability to sort of read a phase diagram! I'm embarrassingly excited to have found this playlist! Yes, I already watched the mineralogy playlist, excellent excellent stuff! Thanks 💖

[@KerriEverlasting]

Igneous rocks rich in quartz! Woooo! Intrusive, platonic. Omg im finally finding the rocks I look at every day. This is so epic. I'm so grateful 💖

[@KerriEverlasting]

Ohhh I get it now!!! Omg you are amazing I love you so much!! I can read the graph better wowee!

[@pukulu]

I was an undergraduate rather a long time ago, but I took lower division geology and remember a field trip to a beach in Humboldt county where there was a large outcropping of green-colored olivine. Since Olivine weathers very fast when exposed to water and air, the outcropping was fairly recent.

[@TomG-f4r]

Cords?

[@JoesFirewoodVideos]

Rachel you rock! Very informative and interesting video. I ❤️GEO GIRL

[@GEOGIRL]

Thanks! Glad you enjoyed it ;D

[@reshavgupta1172]

Ma'am all these lessons are exceptionally good and easy to understand. Is there a way we can download these slides as well?

[@navamilal26]

I was in search of something like this and hopefully found it! Thank you for such an informative video.

[@GEOGIRL]

Thanks so much for the comment! I am so glad you found the video helpful ;D

[@jan_kisan]

oh, yeah, i remembered! we'd just had a class on describing space objects with that student, and i was looking for a video about Europa. yours popped up, and that's how i found your channel. yeah i know i'm writing that in the wrong place, but who cares)))

[@TheIibb2007]

Thanks for this excellent video

[@GEOGIRL]

Of course! So glad you found it informative ;)

[@christianchayna9634]

Geo-girl an amazing channel, thanks 4 sharing bro!

[@GEOGIRL]

Of course! Thanks for the comment, so glad you like the channel! ;D

[@brijbalasingh6470]

Amazing content , yet it would be helpful to understand for people whose english is 2nd language , they need to hear every word , clearly. This would help a wider genre of people who are intrested , & you seem to know a lot , like your own knowledge, its very insightful ,keep up the good work 🙏🙏🙏

[@GEOGIRL]

Thanks so much! And thank you for the feedback I appreciate that. Would subtitles help? Or would you rather hear the lecture than read it?

[@brijbalasingh6470]

@@GEOGIRL can we listen as well as read , the content on the screen is okay , can read with pause , yet your side notes that explains & inform further , must be read & learned, cause they seem more important if ever to research or do field work , Thank you very much ... 🙏

[@achyutapandey5934]

Good contet...

[@GEOGIRL]

Thank you! :)

[@roshansharma868]

Basalt is a mafic Igneous rock with 45 to 52% silica content ....but the IUGS classification (pic attached) define basalt as a rock that contains a max of 20% quartz .....why this difference is there plzz can you clear this doubt?

[@GEOGIRL]

Well basalt is a fine-grained volcanic rock so we use the volcanic classification diagram at 19:18 to define basalt and on this diagram, it is correctly defined at containing ~45 to 52 % silica. Now, if you are asking about gabbro (the coarse-grained equivalent to basalt), which is defined as containing a maximum of 20% silica on the IUGS diagram, it is because for the IUGS classification of coarse-grained (extrusive) igneous rocks, we use modal mineralogy (which is volume percent), whereas in the fine-grained classification system, we use normative mineralogy (which is weight precent), so they are just a bit off. Hope that makes sense, if you want to see the video where I discuss the difference between mode and norm, here it is: kzbin.info/www/bejne/qJ3bmmyJf7ymgLM Thanks for bringing up this important question! ;)

[@rautenbruder1426]

Thanks !

[@crabcrab2024]

You created a wonderful channel. Thank you. My like and subscription.

[@GEOGIRL]

Thank you so much! :D

[@natinaelkassa1411]

you are a sign of quality

[@GEOGIRL]

Wow, this is so nice, thank you so much!

[@kobytavel8631]

thank you

[@ahsankachannel6430]

when will the part 2 coming of igneus petrology ...i am anxiously waiting...and you videos makes me liteally to fall in love in everything you have. You are insane , your every word is full of depth and thats my most fvrt part in geology.Stay blessed , love from Pakistan

[@GEOGIRL]

So far, there have been 6 igneous petrology videos now, I hope you have found the others, you can go to the playlists page on my channel if you want to watch all ig pet videos in order: kzbin.infoplaylists. But if you are asking about the 2nd part to classification with the examples, I am still trying to get the materials I need for that video, because I want to make sure I have all the rock examples I need, and so far my search has not been complete. Hopefully it will be soon though :) ALSO, thanks so so much for the kind words of support and encouragement, you are the best ;)

[@sleepygrumpy]

Very detailed -- excellent work

[@GEOGIRL]

Thanks so much! Glad you enjoyed it ;)

[@stephenelberfeld8175]

I followed an old Essex Co. MA geology book to locate a nephaline-syenite dike in Salem, MA and found some green nephalene with a little blue sodalite. There was some greyish dark material that had a purplish appearance through the edges that I at first thought to be labradorite, but later realized that feldspar type was on the wrong end of Ca-Na-Ka grouping for nephalene syenite. What I was finding was a pseudomorph gradation between nephalene and sodalite, which the old geology book seemed to confirm. The curious thing about sodalite is it must have at some point been exposed to salt water to pick up chlorine to change from nephalene. Otherwise it may have picked up a Sulphur molecule to become lazurite. I once attended a lecture about Japanese ultramafic minerals where rare iodine minerals were formed when magma was exposed to ocean water. The subjects of your lectures always draw me into places where I can put most of the puzzle together but never completed.

[@محمدسعيد-و8م3ج]

I dont understand it ever like that before ❤ thank soooooo much

[@محمدخالد-ع8ر2ن]

Amazing video thank you, but i have a question how can we measure the mineral percentage in thin section

[@emmah794]

Hehehehehe, pregaming my igneous petrology class with these videos :)

[@GEOGIRL]

Oh wow! You are on top of it! You are going to ace that class ;)

[@abhinavpandey7632]

Informative talk 👍🏻

[@GEOGIRL]

Thanks! Glad you found it helpful :D

[@RaviKumar-ls5un]

very helpful viedo at the time of exam..thanks

[@GEOGIRL]

So glad you found it helpful! Best of luck on your exam! ;)

[@teneoaristocrata3270]

Very helpful. Thanks

[@GEOGIRL]

Hey, thanks for the comment once again! haha, I just noticed you commented on both this and the optical mineralogy video, thanks so much, your support means a lot

[@lobstapartay]

komatiite pronunciation! Thanks for the super videos!!

[@oliverweeweepie3132]

Love Theo ❤️❤️❤️

[@varshayadav2343]

Thanks 😊

[@adamc1966]

My favorite type of rock.

[@partm1297]

Hello, at 12:23 where were you able to obtained the square-shaped diagram?

[@GEOGIRL]

That is a figure from the textbook I used, Earth Materials by Cornelis Klein & Anthony Philpotts: amzn.to/3CwyBwY

[@kayalvizhi7611]

@7:08 so the mineral composition of volcanic and plutonic rocks are the same? The different names for volcanic and plutonic basically just tells you whether the rock cooled inside & is coarse grained or if it cooled outside and is fine grained? Like for example basalt and gabbro are compositionally equivalent except for the location where they cooled-right? Also the diagram at 7:08 is a much more simplified version of QAPF /volcanic rock diagram classification correct?? QAPF (& ultra mafic chart) are much more detailed diagrams to identify plutonic rocks and the IUGS volcanic diagram is used to identify volcanic rocks?

[@GEOGIRL]

Yep, the composition is the same between volcanic & plutonic rocks, the only difference is the grain size, see this video kzbin.info/www/bejne/pWOaanWiaaeLbsU for more on identification of the two types. But yes, you are exactly right that the different names just give you an idea of the cooling environment/rate. Also, yes, the 7:08 diagram is a simplified version a bit easier to read than the QAPF (and it is based on silica content and mineral volume % rather than Quartz, Alkali feldspar, Plagioclase, & Feldspathoid content). And yes, IUGS for volcanic (fine grained) rocks, QAPF for plutonic, and ultramafic for ultramafic ;)

[@kayalvizhi7611]

@@GEOGIRL thank you so much!! I’ve been binging your videos, you’re a GREAT teacher

[@ameliepamelie_88]

I thought mica's were felsic? at least for muscovite. Or are there mafic mica's as well?

[@GEOGIRL]

That's a great question! Yes, there are mafic mica in addition to felsic ones like muscovite. The most common mafic mica is biotite! :D

[@zenithparsec]

There's a mislabeled granite in the grid with the samples in it: There are two labeled "Q Monzodiorite", but the middle one should be "Q Monzonite".

[@mirsapp]

You have good presentation skills 👍

[@GEOGIRL]

Thank you ;)

[@ritesh-arya]

Hi like your way of presenting the geological information I am making a museum of evolution based on fossil Would love to talk with u regarding this

[@royaleblizzard2460]

Hey Girl, can you explain about Carbon dating in details I know its not always used in Geology but rather for Fossils and Artifacts research.

[@GEOGIRL]

Yea, actually I have a radioactive/absolute dating video in which I discuss carbon dating, but it is kind of an old video and I didn't go super in depth over C dating, so watch that one here: kzbin.info/www/bejne/fInRYp6Xg611e8k and then let me know if you'd like a more detailed one or if the info in that one sufficed. Thanks! :D

[@royaleblizzard2460]

@@GEOGIRL Thanks.......I need to learn more for my Archeology Studies

[@stevegerry8693]

perfect

[@user-uj8qh8rh2f]

Can you tell me differences & similarities between basalt&gabbro! Also rhyolite&granite?!

[@GEOGIRL]

Yep, basalt and gabbro have the same composition but have different grain sizes (basalt if fine grained, gabbro is coarse). Same for granite and rhyolite (same composition, but rhyolite is fine grained, granite is coarse grained).

[@user-uj8qh8rh2f]

@@GEOGIRL Good, Thank you.

[@colubrinedeucecreative]

Before we get started, so nebula happens and then it is time and temperature that determines the make up, so does this mean in other systems potentially would form similar if not the same materials given the time, speed, and temp were similar? Is the sun kind of like lava in a way? I mean I know that sun is a plasma but we can create plasma in the microwave so it melts minerals, well dangit I have a real hard time understanding the sun. lol

[@GEOGIRL]

Haha, don't worry I don't understand the sun that well either lol. But to attempt at answering your questions, yes, other planets/systems with the same elements are able to (and do) form the same materials/minerals as found on Earth. In fact, all of the rocky planets in the inner solar system have the same bulk composition for this very reason. However, I think that the sun isn't able to make these types of materials because it goes back to that concept of if it gets too heavy into element making (up to Fe) and it explodes, and given that our sun is relatively young, it hasn't even gotten to making elements much heavier than H and He (I think the sun is something like 98% Hydrogen and Helium, the lightest two elements), and this means that it is nowhere near as heavy as the elements that make up lava on Earth (which is mostly Si, O, Fe, Mg, Na, K, Al, etc.). Once our sun does get old enough to start making heavy elements, it will still only make a very small amount (relative to H & He) at its core before it explodes, so I don't think it is possible for stars to create the minerals that we have on Earth. The reasons for this are very physics-y and I am no physicist so I am sorry but I can't explain further haha. But I really appreciate the question, I bet a lot of people think the sun is lava because it looks that way!

[@colubrinedeucecreative]

@@GEOGIRL Awesome, thanks so much! I haven't really thought about that as a comparison before, but sunspots look like a spew of lava almost.

[@jawadsyed6385]

I decided to listen to you than to download various research papers and study

[@GEOGIRL]

Great plan, best of luck! ;D

[@RaviKumar-ls5un]

whats the scope of geology in future

[@GEOGIRL]

What a great question! I don't think I am qualified to answer that with my limited experience, but I am hoping that geology becomes very popular among young students as we need to understand the complex processes of Earth better than ever now! I know that currently geology is going down in popularity among undergraduate students, but I hope they will soon see how much variety geology holds and that it is not only oil, gas, mining, but also climate and environmental science, and pretty much anything that happens on Earth and that we need people in all of these fields in order to unravel the geological mysteries that Earth and other planets still hold. :)

[@RaviKumar-ls5un]

@@GEOGIRL 🤔🤔❤️❤️

[@abdidaniel1162]

how each mineral for first time on wo done see then how understand

[@Grapevinemammi]

Geo test on igneous petrology in a few hours😅

[@SilasSulei]

🎉

[@airuca4330]

I didn't see diorite igneous LoL I'm trying so hard to identify this stone

[@GEOGIRL]

Check this video out: kzbin.info/www/bejne/pWOaanWiaaeLbsU (I talk about and show examples of diorite in that one at around 9:50) ;)

[@airuca4330]

@@GEOGIRL thank you I have 1 I believe is diorite but it has iron spots and the mica is damaged from the water. I wish KZbin allowed us to upload pictures LoL thanks again 😁

[@Selva..yb3iv]

How do I get the PPT???

[@sushil1484]

I love you😍😘

[@musharafkhan7668]

it is very interesting video.please send me mineralogy notice.

[@GEOGIRL]

Thanks! But what do you mean mineralogy notice? You mean when I post mineralogy videos? I have a whole mineralogy playlist if you are interested: kzbin.info/aero/PL69bBhmsrgftKxwTlJAvkSlQ-gTB8o_Xp Hope this helps! ;)

[@padogeology1776]

Hiii miss's I m from India can you send this book

[@GEOGIRL]

Hey there! Sure, here are the links to the books I used for this playlist: Essentials of Igneous Petrology by Ronald and Carol Frost: amzn.to/3fJ94XD Earth Materials by Cornelis Klein & Anthony Philpotts: amzn.to/3CwyBwY The one I used most for this video specifically is the first one (Essentials of Igneous Petrology) Hope this helps ;)

[@TomG-f4r]

Grology deserts me , earrh has held me down ! Astronomys to far ,distant an remote ,ly glitterefferious...nightlights fo pixies...the present and the future tis in meteorites . Come run away , wit me !

[@anarcho-geologist4528]

OH MY GOD IGNEOUS ROCK CLASSIFICATION THIS IS ONE OF MY FAVORITE SUBJECTS I CANT BELIE- Hsj83655jdje5h8o72ndheyeukxiijjjjjjj🤪🤪🤪

[@GEOGIRL]

AHHHH YAYYY!! hahaha So glad you are excited for this playlist, hope you enjoyed the first video, the second comes out this Sunday! ;D

[@koboldgeorge2140]

Yo you should start adding lofi hip hop beats to your videos. I feel like it would add a very chill vibe and help me focus more easily on what you're saying

[@sebuktegin4403]

Hell No! Not everyone can focus with music playing in the background. Play your own lofi in another tab if you want it so much.

[@kronigen]

please don't, I can't study with music playing in the background

[@happygwayi7600]

Aaaaah i can't even get anything from your video, your too fast eeeh

[@GEOGIRL]

Haha, Sorry about that, you can actually slow down the speed of the video if it is too fast for you to follow ;)

[@paulsmith3968]

Slow down

[@DeeDurand-wm4sf]

Geico sucks , sorry but it is true .