Great discussion. And speaking a geologist who started the journey in 1973... I think that this is just outstanding! Not everyone needs to understand the vast, but arcane distinctions within the field of igneous petrology. And if you teach just a few people -- especially young geology students -- about granites, granodiorites, diorites and gabbros, you still earn your angel wings.
Thanks. I like the Willsey way. It seems maddening trying to keep all the intrusives separate. I roam all over in the elkhorn mountains of Eastern Oregon where each of so many separate plutons are slightly different
Hell YEAH the "Willsey Way" is helpful! I couldn't possibly remember all these without your sampling and your keeping them _simply_ categorized. After this episode I'll know much better what I'm looking at when I venture out to more plutonic landscapes and batholiths like the Sierra Nevada.
Really enjoy all your videos. A great place to see all of the granitic rocks is a large older cemetery. The headstones are made of every type of granite and the minerals really stand out in the highly polished ones.
Many thanks for putting these videos together; really enjoyable, especially the field trips. I'm actually a retired secondary school chemistry teacher from the UK. In the mid 1980s our Dept for Education & Science introduced a national curriculum which, for the first time, included some geology for all 11-16 yr old pupils. Since there were very few geology teachers in schools, the civil servants very kindly slipped the geology into the chemistry syllabus. If only we'd had the internet & your TH-cam channel back then!
Thanks Shawn. I hike and backpack in the Cascades of Washington and often wondered what types of igneous rocks I was walking on. There are a lot of plutons and of course stratovolcanoes so you see intrusive and extrusive igneous rocks. This will help me get a general sense of what they are. So thank you!!!
Very well done! My detailed knowledge of intrusive rocks is about the same as yours. I was taught that, as in your notes, the defining difference between Granite and Granodiorite is the relative abundance of K-spar and Plagioclase, so K-spar>Plag means granite and Plag> K-spar means granodiorite, regardless of the mafic content. By that definition,when you line up the rocks for comparison at 15:00 the version of granite you show looks to my eye like granodiorite, with an abundance of white Plag. Gabbros often confuse my students because the Ca-rich plagioclase dominant in the first example you show here is medium gray, making the rock appear lighter in color than they expect for a mafic rock (much lighter than basalt, for instance). As someone mentions below, wandering through the Sierra or any granitic mountain range brings this all back, as there is always such variability from pluton to pluton!
@@shawnwillsey It absolutely works! For those of us avocational geology nerds who didn't get formal training in this stuff, the "Willsey Way" has simplified this for me tremendously. A big thank you. Looking forward to the extrusive series.
Thanks again Shawn for another really good video. It’s ok. I only really need to know and understand these 4 intrusive igneous rocks for now. If I could just learn to tell the difference, I would be very happy! I have several granite or granitic samples here. I must line them up like you did and see what I have. I am amazed how different the granites are. From bright white from Yosemite to pinky from the Idaho Batholith to Golden Horn batholith.
Thank you for these videos! I have always been interested in geology, but I never had the opportunity to study it, your videos given me the chance to learn. I am getting to the stage where I can recognise and name features, all because of your videos!
Thanks so very much for this. I have just discovered you last week. I'm really dipping into geology in my old age. I trained in Anthropology and education. I have been following Nick Zentner for a bit over a year. Although I was aware of him through PBS. I live in Central Washington a valley north of where Nick lives. I am also a half hour drive from the edge of the Mt Stuart batholith. The "granite" I love is in the Stuart's. I believe it is a granodiorite. This video is very helpful to me. I also watched your video on old Yellowstone. That is another place dear to my heart. I also love the basalt flows that edge parts of my valley. I am happy to find another geologist explaining to people who are at the beginning level. I would like to learn more about Craters of the Moon. I was there in '81 when we camped there on the way to Yellowstone. Thank you again.
Thanks for another great video. I really enjoy the field trips. In being around the Sierra Nevadas here in California, these samples you are showing have a Field Classification as Leverite. Keep up the great work you are doing.
I'm a hobby machinist and bought a granite surface plate. It is very dark colored. Called black in the trade. The granules seem quite fine. For a lot more $ they sell "pink" granite surface plates that are claimed to be harder and longer lasting. True? The counter top shop nearby has a huge selection of granite slabs. Some really wild in color & pattern. I think almost all granite counter tops are treated with resins to fill the fine voids.
I live in the UK, in Cornwall at the foot of Carn Brea, Redruth. This was a four mining area especially in the 1800 s. Carn Brea is comprised of intrusive granite into Devonian slate. Carn Brea is only one lobe of a larger granite mass below Cornwall and west Devon. Good video!
I'm not a geologist, maybe a rock hound, but by design an artist that works from the natural world. Made many rock and rocky landscape works so I'm enjoy understanding when gathering source information. Shawn have you been to the Acadia region of Maine and the coastline? Perhaps my own favorite place in the US.
I like the Willsey way. I do think you should include peridotite. Who can resist a green rock? We used to have a cat named Peridot, and when she was naughty we addressed her as Peridotite.
This was a great introduction to igneous rocks. I live in an area that has tones of igneous rocks, which I have generally called granite in the past. Your examples really help with the differences. Can you suggest a fellow TH-camr or a webpage where o can dive deeper with an Igneous petrologist? I’m wondering about Grus and the chemical weathering involved with creating that. There are places where I live that have large granitic rock outcrops right next to large hills of Grus.
OMG!, Shawn. Thank you for this short, concise discussion and demonstration. I am a rabid fan of Nick Zintner. I am a slow leaner and needed this format to be able to focus on the subtle differences in the igneous rocks. Will make flash cards to help cement them. Watched the sinking Valley, have you considered looking at the slipping cliff side at Union Gap near Yakima WA off I-84? Potentially, a real large event. Don't know why it separating. Thanks for the video.
When we think of people from the Stone Age, it would be entirely wrong to think of them as less intelligent. The people of that age knew their stones intimately, at least from the entirely observational perspective. The atomic (modern chemistry) perspective developed slowly, later on. But they must have had considerable knowledge that was lost later because technology hadn't developed good methods yet for preserving detailed information developed from reflection, like complex writing. Knowing the rocks that surround us has always been part of human survival and continuity (so far, at least). If you were person living in the Stone Age, you had to understand a great deal about the rocks. Otherwise you weren't going to survive against the ravages of nature and competition from unfriendly sources that were doing their own thing to survive.
How about granite that's used for countertops? Are they all real granite or are they also gabbros and diorites that are sold as granite for countertops? Can they even be mined in that format?
Is there a way for an uneducated amateur to have some of their rocks identified? I have a few that are interesting to me and my kids that we'd love to know more about.
The earth continues to cool, despite the contribution of heat from the atomic decay of the heavier atoms and elements that are increasingly drawn into deeper layers. The outer, lighter, silica rich layers continue crystalize. Extrusive blobs (lava) tend to form without significant crystal formation due to the time it takes crystals to form in the matrix solution. Intrusive rocks (much slower cooling) tend to form much more complex and tighter crystals, largely related to their chemical composition. Bowan's Reaction Series is very useful in understanding the sequence of this crystal formation. The mantle is somewhat turbulent, partially related to tectonic processes. Bowan's Reaction Series does not (cannot) account for the all the variety in plutonic rocks...granites. hth
Always seemed to me growing up it was more TWO main types of rocks..sedimentary formed one way, then igneous & metamorphic were two forms of the same process....melting of rock materials & then the cooling & various amounts of pressure over eons that made them ..obsidian or granite or other various types, but on the same heat/pressure continuum as opposed to sediment piling up & hardening, and calcites, other seepage, through the porous sediment,
Potassium contains parts calcium sodium Rock salt sodium colors test white red.seasalt sodium glass's... ..cristlaiginh .180.dig.90 dig eq.moon. sun. 24 h.trams.agate😊
And now people know where their countertops come from. Heh. You invite your geologist friend over for dinner and for smalltalk he describes the mineral content of your kitchen counters. Also, coming spring 2023: Godzilla vs Granitoid.
Intrusive features like dikes, batholiths, etc. have always fascinated me. They give you a peak into the behavior, distribution and movement of magma underneath our feet. So fascinating.
Thank you for these rock idenitifcation vlogs. They make me feel like I am actually in class. Love it!!
You are so welcome!
Great discussion. And speaking a geologist who started the journey in 1973... I think that this is just outstanding! Not everyone needs to understand the vast, but arcane distinctions within the field of igneous petrology. And if you teach just a few people -- especially young geology students -- about granites, granodiorites, diorites and gabbros, you still earn your angel wings.
Thanks. I like the Willsey way. It seems maddening trying to keep all the intrusives separate. I roam all over in the elkhorn mountains of Eastern Oregon where each of so many separate plutons are slightly different
Hell YEAH the "Willsey Way" is helpful! I couldn't possibly remember all these without your sampling and your keeping them _simply_ categorized. After this episode I'll know much better what I'm looking at when I venture out to more plutonic landscapes and batholiths like the Sierra Nevada.
Really enjoy all your videos. A great place to see all of the granitic rocks is a large older cemetery. The headstones are made of every type of granite and the minerals really stand out in the highly polished ones.
Many thanks for putting these videos together; really enjoyable, especially the field trips. I'm actually a retired secondary school chemistry teacher from the UK. In the mid 1980s our Dept for Education & Science introduced a national curriculum which, for the first time, included some geology for all 11-16 yr old pupils. Since there were very few geology teachers in schools, the civil servants very kindly slipped the geology into the chemistry syllabus. If only we'd had the internet & your TH-cam channel back then!
Hi Shawn, oh good, rock id.. I've been able to ID some rocks I collected. No fancy, I'm hanging in so far.
What a treat to see your samples of lava and rock types! Thank you!
Thanks Shawn. I hike and backpack in the Cascades of Washington and often wondered what types of igneous rocks I was walking on. There are a lot of plutons and of course stratovolcanoes so you see intrusive and extrusive igneous rocks. This will help me get a general sense of what they are. So thank you!!!
That is awesome!
This was great. I really appreciate you covering the basics. Helps it sink in a bit more.
Thank you for these videos, very helpful as I try to share more of the outdoors with my children!
Wonderful!
Very well done! My detailed knowledge of intrusive rocks is about the same as yours. I was taught that, as in your notes, the defining difference between Granite and Granodiorite is the relative abundance of K-spar and Plagioclase, so K-spar>Plag means granite and Plag> K-spar means granodiorite, regardless of the mafic content. By that definition,when you line up the rocks for comparison at 15:00 the version of granite you show looks to my eye like granodiorite, with an abundance of white Plag.
Gabbros often confuse my students because the Ca-rich plagioclase dominant in the first example you show here is medium gray, making the rock appear lighter in color than they expect for a mafic rock (much lighter than basalt, for instance).
As someone mentions below, wandering through the Sierra or any granitic mountain range brings this all back, as there is always such variability from pluton to pluton!
Thanks! It's tricky teaching this stuff. Hope my simplified approach works for some folks. Thanks for watching.
@@shawnwillsey It absolutely works! For those of us avocational geology nerds who didn't get formal training in this stuff, the "Willsey Way" has simplified this for me tremendously. A big thank you. Looking forward to the extrusive series.
I really enjoyed this, I have some nice examples of Pink Shap Granite ( Northern England ) in my collection.
Thanks again Shawn for another really good video. It’s ok. I only really need to know and understand these 4 intrusive igneous rocks for now. If I could just learn to tell the difference, I would be very happy! I have several granite or granitic samples here. I must line them up like you did and see what I have. I am amazed how different the granites are. From bright white from Yosemite to pinky from the Idaho Batholith to Golden Horn batholith.
Yes so much variety. Good luck and hope this helps.
Thank you for these videos! I have always been interested in geology, but I never had the opportunity to study it, your videos given me the chance to learn. I am getting to the stage where I can recognise and name features, all because of your videos!
Glad you like them! Love that it’s helped you.
Thanks!
thanks for your enthusiasm teaching us about Igneous rocks as it was my phobia before back in the class of geology , you made it again
Thanks so very much for this. I have just discovered you last week. I'm really dipping into geology in my old age. I trained in Anthropology and education. I have been following Nick Zentner for a bit over a year. Although I was aware of him through PBS. I live in Central Washington a valley north of where Nick lives. I am also a half hour drive from the edge of the Mt Stuart batholith. The "granite" I love is in the Stuart's. I believe it is a granodiorite. This video is very helpful to me. I also watched your video on old Yellowstone. That is another place dear to my heart. I also love the basalt flows that edge parts of my valley. I am happy to find another geologist explaining to people who are at the beginning level. I would like to learn more about Craters of the Moon. I was there in '81 when we camped there on the way to Yellowstone. Thank you again.
I have three or four videos from craters of the moon here for you to enjoy.
Very informative and should prove useful. Thank you.
Really a treat. Thank you for your simplified description.
Glad you liked it!
Thanks for another great video. I really enjoy the field trips. In being around the Sierra Nevadas here in California, these samples you are showing have a Field Classification as Leverite. Keep up the great work you are doing.
Thank you!
I’m spreading the news. Local Rock Clubs are looking for just this kind of information.
Such a great series. Thanks for doing this.
Glad you enjoy it!
I'm a hobby machinist and bought a granite surface plate. It is very dark colored. Called black in the trade. The granules seem quite fine. For a lot more $ they sell "pink" granite surface plates that are claimed to be harder and longer lasting. True?
The counter top shop nearby has a huge selection of granite slabs. Some really wild in color & pattern. I think almost all granite counter tops are treated with resins to fill the fine voids.
We'd need to see the mineral composition of both materials to asses their durability and hardness.
I live in the UK, in Cornwall at the foot of Carn Brea, Redruth. This was a four mining area especially in the 1800 s. Carn Brea is comprised of intrusive granite into Devonian slate. Carn Brea is only one lobe of a larger granite mass below Cornwall and west Devon.
Good video!
16:35 This part was really interesting to me. Lava chemistry. ;-)
I'm not a geologist, maybe a rock hound, but by design an artist that works from the natural world. Made many rock and rocky landscape works so I'm enjoy understanding when gathering source information. Shawn have you been to the Acadia region of Maine and the coastline? Perhaps my own favorite place in the US.
Thank you
Looks like the rocks we have in abundance around here and abouts... Mt San Jacinto, in So Ca. I like to see a lot of K spar in my Granite!
That was helpful. Thank you again.
You're welcome!
Beautiful work brother😊
Thanks. Learning a lot.
Incredibly helpful! Thanks so much!
Glad it was helpful!
Thanks ❤❤❤
I like the Willsey way. I do think you should include peridotite. Who can resist a green rock? We used to have a cat named Peridot, and when she was naughty we addressed her as Peridotite.
Excelente video resumen. No soy de la rama pero estoy aprendiendo sobre rocas . Gracias y saludos !
Muchas gracias amigo. Me alegra que to gustan estos videos.
Great job on diorite!
The Willsy way works for me!
Agates. If you haven't talked about them yet I'd love to hear more about them. Thanks!
These were mentioned in the mineral video series along with other varieties of quartz. th-cam.com/video/hR11k0S3SiI/w-d-xo.html
HAVE MY SELF COLLECTED ROCKS IN FORNT OF ME TO GEET THIS RIGHT
THANK YOU SHAWN
This was a great introduction to igneous rocks. I live in an area that has tones of igneous rocks, which I have generally called granite in the past. Your examples really help with the differences. Can you suggest a fellow TH-camr or a webpage where o can dive deeper with an Igneous petrologist? I’m wondering about Grus and the chemical weathering involved with creating that. There are places where I live that have large granitic rock outcrops right next to large hills of Grus.
Thank you for information
Thank you!
You're welcome!
OMG!, Shawn. Thank you for this short, concise discussion and demonstration. I am a rabid fan of Nick Zintner. I am a slow leaner and needed this format to be able to focus on the subtle differences in the igneous rocks. Will make flash cards to help cement them. Watched the sinking Valley, have you considered looking at the slipping cliff side at Union Gap near Yakima WA off I-84? Potentially, a real large event. Don't know why it separating. Thanks for the video.
Glad you enjoyed it!
Thank you willsey
I am inspired to go back to college a 4th time and study geology, if I can find a program close to me here in Southeast TX. Thanks for these videos.
Thanj you, iam learning so much . ❤😊❤
When we think of people from the Stone Age, it would be entirely wrong to think of them as less intelligent. The people of that age knew their stones intimately, at least from the entirely observational perspective. The atomic (modern chemistry) perspective developed slowly, later on. But they must have had considerable knowledge that was lost later because technology hadn't developed good methods yet for preserving detailed information developed from reflection, like complex writing. Knowing the rocks that surround us has always been part of human survival and continuity (so far, at least). If you were person living in the Stone Age, you had to understand a great deal about the rocks. Otherwise you weren't going to survive against the ravages of nature and competition from unfriendly sources that were doing their own thing to survive.
Very helpful.
Plag in felsic rocks would be mainly sodic end member of the plag solid solution series.
Hey got any tips for shaping diorite?
THANKS
How about granite that's used for countertops? Are they all real granite or are they also gabbros and diorites that are sold as granite for countertops? Can they even be mined in that format?
Is there a way for an uneducated amateur to have some of their rocks identified? I have a few that are interesting to me and my kids that we'd love to know more about.
Maybe contact a local college or museum?
If Andesite cools quickly does it lack the Chrystals that identify it but still be Andesite but just a flat dark grey in colour
Yes, although most andesites will have visible crystals.
Thanks for reply
❤❤
The earth continues to cool, despite the contribution of heat from the atomic decay of the heavier atoms and elements that are increasingly drawn into deeper layers. The outer, lighter, silica rich layers continue crystalize. Extrusive blobs (lava) tend to form without significant crystal formation due to the time it takes crystals to form in the matrix solution. Intrusive rocks (much slower cooling) tend to form much more complex and tighter crystals, largely related to their chemical composition. Bowan's Reaction Series is very useful in understanding the sequence of this crystal formation. The mantle is somewhat turbulent, partially related to tectonic processes. Bowan's Reaction Series does not (cannot) account for the all the variety in plutonic rocks...granites. hth
Never heard of potassium feldspar.
❤
Always seemed to me growing up it was more TWO main types of rocks..sedimentary formed one way, then igneous & metamorphic were two forms of the same process....melting of rock materials & then the cooling & various amounts of pressure over eons that made them ..obsidian or granite or other various types, but on the same heat/pressure continuum as opposed to sediment piling up & hardening, and calcites, other seepage, through the porous sediment,
No melting is involved with metamorphic rocks. Otherwise, they would be igneous rocks (melted rock).
👍
Potassium contains parts calcium sodium Rock salt sodium colors test white red.seasalt sodium glass's... ..cristlaiginh .180.dig.90 dig eq.moon. sun. 24 h.trams.agate😊
You shouldn't just take things for granite (said the igneous petrologist to the field geologist)... 😉
Also: Don't mix up Gabbroids with Graboids (ref.: Tremors et al. 1990) 😂
Those are enough names.
I hope you translate all of your clips into Arabic so that we can benefit from them and learn from them
And now people know where their countertops come from. Heh. You invite your geologist friend over for dinner and for smalltalk he describes the mineral content of your kitchen counters.
Also, coming spring 2023: Godzilla vs Granitoid.
Intrusive features like dikes, batholiths, etc. have always fascinated me. They give you a peak into the behavior, distribution and movement of magma underneath our feet. So fascinating.
Thank you for the info