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As a native of Maine? And still live here? AND as a geology geek? Well done❤

I would include introducing what we are looking at. you did say tillite and cobble but not gowganda. nice find!

I hiked all those trails: Old Rag, Little Devil's Stairs, Catoctin. Indeed I climbed Old Rag about 45 times since 1981 when I first arrived in the US. Amazing to find out that the Old Rag granites are a billion years old. In related news, what caused the earthquakes in 2010 and 2011, the first epicentered in Germantown, MD and the second in Orange, VA? Both of these are located squarely in the Piedmont. (I experienced both of these: the first one, at 5am was a single pulse where we were, which told me that (a) it was an earthquake, and (b) we were right on top of it. I called in in to the USGS, but they already knew about it).

I made it to GNP in May 2024 and this video greatly enhanced my appreciation of the rocks in the park. Thank you!

Frickin’ awesome demonstration! And, THREE new vocabulary words: concentric ribs, plumose lines and hackles.

At the 7:00 mark you can see that there is no evidence of “bio-turbation” that would be caused in modern deposits by burrowing worms and mollusks. The thin laminae are perfectly preserved. You can see living stromatolite mounds at the Hamelin Pool at Shark Bay in Western Australia. Access is limited, by there are plenty of images on-line.

8:20: for the summary, what is the sample (water or ice) from which you calculate H/D? thank you

much appreciated to talk at the outcrop, it makes it so much more interesting

Thanks for sharing! Do you know if they will be offering other 2YC instructor expeditions in the future? Seems like a fantastic experience.

Great video thank you

The measuring of Hydrogen isotopes is new to me. Makes sense. My understanding is what you mention later in the video, in measuring the oxygen isotopes stored in oceanic creatures, like diatoms, that use the oxygen available at the time to generate a shell. And then when that creature dies and it sinks to the bottom of the ocean. Over time you get ocean floor layers that are sometimes rich in Oxygen 16/18 alternating with ones that have lower in oxygen 16, as they have evaporated and been stored in ice sheets. Cool presentation though, much more thorough in the whole picture. Your students are lucky to have a teacher like you.

That was such an amazing demonstration! Helped a lot by your explanation. I had no idea that was what the rest of a dike looked like. I drive by a few magmatic intrusions into granite canyons, darker intrusions that have a much finer crystalline composition than the surrounding granite. But yeah, all I see is the crack like feature as seen from the side. I am a total newb to geology, just do it for fun. Lucky to be surrounded by cool geological features. Granite. Basalt columns. An old volcanic vent. And even a moubtain littered with oceanic fossils. Realizing enjoyed stumbling on your channel. Cheers

This is great, probably the "cleanest" description (sometimes cartoons serve their purpose) of how we arrived at the current formations around the Blue Ridge, to be fair I've heard bits and pieces of this story before but this helps tie my understanding together and will help me when I'm hiking sections including the AT and seeing greenstone, various Chilhowie formations and intrusive granite like at Old Rag Mountain.

thank you 💪🏼💪🏼💪🏼💪🏼

Lots of good information in this video for depositional environments. Very helpful thanks.

The peninsula rock outcrop tends to have a copper-color patina on it. Any idea what causes that?

Are there any fossils present (ichnofossils maybe) to help further pin down the depositional environment? Or even to help with determining the age, or was there another way the age has been radiometrically determined if not relatively through fossils? First video i stumbled upon and definitely won't be last, keep up the good work! 😁

Thank you for Sharing!

I thought you were a very big fish at first which I guess considering evolution is sort of true in a way

That community college is lucky to have you

Thank you for sharing your knowledge

Thanks for another field trip geo explain! I'm really enjoying experts getting out in the field and presenting "roadside geology" to the public. You, Shawn Willsey, Myron Cook, Dr Nat and, of course Nick Zentner are all doing some great outreach. I wish every state had an outreach expert, with their own YT channel.

First! 🪨

I’ve been looking for detailed info on glacier’s geology for year! This is great. I’ve made several video guides on GNP and want to add more geology learning. this will help a lot. FYI my GNP vids over a million views are you available to answer Qs? Or maybe even be interviewed via zoom? Could be good publicity for your channel.

Fantastic! 👏

Man, a night on CZcams is great stuff. I was very pleased to stumble on this.

Very nice demo, Callan!

I never knew. I'll never look at a fracture the same way again! Thanks for such an informative presentation.

I was excited to actually know some of the stuff about the formation of the basement complex in this video. Looked at the channel name after I finished and realized you're the same guy who posted the lecture 11 years ago that I learned most of that stuff from. My professor has referenced those lectures several times, good stuff

Thank you for this excellent presentation of the Precambrian sedimentation at Glacier Park. When I was in school, they pretty much skipped this part of Earth history. I was/am a sedimentologist, and your presentation was as good and being on a field trip. I've been looking for information on the geologic history of the park because I'm a retired geologist going there in July for a family reunion. They already told me they want me to tell them what was going on here when the rocks were formed. Thanks a lot.

At roughly minute 20 he discusses two different ages in the same rock, saying that the younger one got raised to a temperature of about 400 degrees, no enough to reset the zircon and lead; but wait, how did the temp rise to in the 400s then? Does anyone know? (Enjoying your presentation Callan!)

Incredible. I deal with foundation performance on expansive clay in Austin. Cool geology there.

During winter when its below freezing, the face of the cut is completely covered in massive ice sickles. I always live passing through this area.

15

Brilliant

This is always so good. I keep coming back too him to listen.well spoken, not boring.

Just found your VA Geology video a couple days ago and diving in on the others now. Learning so much about my adopted state's geology. Have been exploring creek and river beds and finding really unusual rocks. Some I've seen in WA state (granites) and others in Colorado and Utah along faults. But here, so many unusual types in a relatively small area that I feel driven to learn more! Thank you for all the informative videos on VA and West VA, etc. Looking forward to more as you explore!

IM YOUR BIGGEST FAN CALLAN 😁😛

this was such an interesting video! made it extremely fun to learn geology thank you!

Black people are carbon beings.

I noticed they are sea floor mapping. It is so cool seeing how tall some of the mountains, volcanoes, seamounts are!

What a cool experience!

slay

Great video!

Sorry, I didn't catch a couple of typos in my post. I'm usually not that careless.

Nice, quick presentation on the Appalachians. The only thing I would add is that some of us think gravity is the key to explaining Appalachian (and Himalayan) structure. During the collisions of Avalonia and Africa, subduction or "underplating" of contintntal crust thickened and (as a result of buoyancy) lifted up the "welt" and the overlying sediments that were originally the continental shelves. Uplifting and deformation of those sediments, and metamorphism of rocks caught up in the rising collision zone put stresses on them that exceeded their strength (just as is now happening in the Himalayas), and the "thrust" faults (actually huge gravity slides) moved off the uplift under their own weight. Those gravity slides formed what is now the Valley and Ridge and the Blue Ridge. As the effects of the collision died and the erosion of the orogen proceeded, the whole area "relaxed", with progressively decreasing uplift until buoyancy ceased to be a driving mechanism. I think too many introductory geology texts overemphasize the idea of rocks shoving eath other around--if that's all that was involved, the deformation zones would be muich narrower. Unfortunately, the term "thrust fault" implies some things that aren't really realistic (at least for the huge, low angle ones), when you consider rock mechanics. Also, plate tectonics itself is a response to gravitational issues--oceanic "ridges" are actually big, broad uplifts (the one in the Atlantic takes up about 1/3 of the ocean basin), off of which new, "hot" oceanic lithosphere slides away from the uplift under its own weight (as do nearby continents). When the oceanic lithosphere cools enough so that its density is greater than that of surrounding rocks, it sinks, again under its own weight, back into the asthenosphere, forming a subduction zone. At that point, especially if subduction occurs on both sides of the spreading ocean, the ocean may begin to contract, eventually closing as a competing ocean opens. This is a Wilson cycle (named for J. Tuzon Wilson). All of this may go beyond what your purpose is in this discussion, but I think it's important to the story as a whole.

God bless you man.

amazing

Great the way it falls back to the original as the pressure is released, just like real strata.....:) :)

Can you Please further describe the change in the depositional environment by making a rough sketch or an animated video.