great video and if a person keeps driving along north shore road its considered the most amazing 40 miles of exposed geology in the world. I live in Vegas and I like hiking to and spotting "time zones and occurences" such as the great dying and we also have cretaceous just east of town as well. Also in frenchman mountain I will be looking to document that there must be alamo impact breccia in the layers roughly half way up from the comet/bolide impact that occurred north of Las Vegas.
That sounds like an awesome project. Please keep me posted and I would love to visit an impact site next time I am out in Las Vegas. I visited the shatter cones outside of Santa Fe and have a video in those if you are interested. Will link.
@@earthandtime5817 thanks. I will be uploading various videos soon especially on cretaceous willow tank formation and other geology of the area. This is a new channel. My other one has 3,000 subscribers but had videos going back 2 decades so I started a fresh channel mainly for geology. I will also be going up Frenchman to locate the alamo impact breccia that reached the area. It would be roughly half way up.
@@joeoutabout2947 thanks for the kind words. It is a beautiful place. Hope to get back and do another video in the geology across the entire Frenchman Mountains.
as far as the uncomformity I am a believer that it represents snow ball earth time in which glaciers helped grind away alot of material which washed away
I actually don’t know much about snowball earth other then what I read about it as an undergraduate. I will need to read up on it. Thanks! Appreciate the comment and knowledge!
Yes! In at least one place in Wyoming in the Big Horn Basis just east of Yellowstone Park, the Great Unconformity exposes 2.8 billion year old Archean gneisses and granites with thinly bedded Cambrian limestones and shales of the Flathead formation deposited on a red granite that looks like it had been smoothed by giant grinder! Here the marine sediments may be peeled back to reveal rock last exposed to daylight more than 500 million years ago! That is evidence of ice sheet abrasion roughly 800 million years ago, .sometime before the supercontinent Rodinia broke up, later to join other fragments to become Pangea.
There used to be a set of nicely thought out informational panels set up at the Great Unconformity site and along the trail leading up the ridge. Frenchman Mountain as a whole is a remarkable geologic phenomenon, known sometimes as "The Mountain that Moved." The block that makes up Frenchman Mountain migrated some 40 miles from its eastern origin site over about a 2 million year period during the Miocene, leaving a trail of volcanoes and shear zones behind it. Unfortunately, those explanatory panels have been destroyed by vandalism, illustrating one of the hazards of trying to preserve and appreciate an urban unconformity.
Thank you for sharing. I read about the info panels and was bummed they were not there. I hope to get back to Frenchman and do a video about the stratigraphic package there and its structural history. Appreciate the extra info.
@@bluwtrgypsy happy new year. 🎆🎊. I hope you and your family have an amazing one! Thanks for being a regular commenter on the channel. I appreciate you!
Hi Garrett. I love to watch those old 1930's B Westerns that were filmed up in Lone Pine, CA. I've never visited, but find the Alabama Hills to be very interesting geologically. If you ever get a chance and can get up that way I would like to learn a little bit about how and why they were formed and their relationship to the nearby Sierras. Thanks.
I enjoy content like this. We live in an amazing world/universe, and thanks to folks like you, I learn more about it every day. The time scale of what you are showing, is mind blowing. The geology tells part of the story, would love to know the rest, which make it a compelling mystery. One of my own local geological places of interest is... A section of cliff face, next to Lake Natoma, in Folsom California, exposed by erosion from the Lower American River. I often see it on bike rides, as it is next to one of my favorite bike paths. It has many layers of sediment including some with fist sized round rocks. What I always wonder is, why such variety of texture, and how that variety got deposited there. I assume it was put there by the river, but I don't understand why it changes so drastically in composition, and even vertical/horizontal orientation. EDIT: I googled it, and learned a great deal about it. Fascinating. Your video inspired me to finally investigate 🙂 Best wishes for your continued success/fun with geology 🌎
So an old geologist here. After a quick look online it appears that at that unconformity in the Cambrian there were no land animals and little in the way of land plants. So what was the rock surface doing over the course of a billion plus years? Was it slowly eroding (of course it was)? Is there evidence in the lower metamorphic layer of differential erosion and stripping away of sediment? Are there erosional features to see? There is enough time for mountains to have built and then eroded to a peneplain during that time.
Good observation. I am not as familiar with the geology there, however there are a lot of granites in Southern California and it could be similar rocks! Thanks for the comment.
For years, I've been hoping that someone would explain the coastal area between Malibu and the Oxnard military base, I get so excited when we drive through there, So. Cal.
Just stumbled upon your channel! Pretty interesting! Anyway, have you been to see the Morton Gneiss in Minnesota, the oldest rock in the US? There's supposedly a display of it in situ at its namesake site of Morton, Minnesota. Of course, there might be some on some buildings in Houston and other big cities you've been to, since it's a popular decorative stone. Also, since I live in Seattle (which has at least one building clad in Morton Gneiss), I have to advise you to check out Nick Zentner's videos on Northwest geology.
While it's not as easy to get to as just driving down Lake Mead, the great unconformity in the Grand Canyon is much more pronounced. Thank you for a great video.
@earthandtime5817 Just below Havasupai Garden, before you get to the Devil's corkscrew you'll cut through the tapeats and can stand with your feet on the vishnu schist and your hand on the tapeats.
Great question. I didn’t take any samples. A thin section would be helpful. I was wondering if it is related to iron staining. I saw evidence for iron staining there.
@@peteklover2923 thanks for sharing. That spot is on my bucket list. I have been in the Grand Canton but I never visited the contact. Someday! Happy new year.
Snowball earth caused sea levels to drop and the ice ground down most of the land. Eventually new volcanoes emitted enough CO2 to warm the earth, melt the ice, cause sea levels to rise, then erosion of the remaining land deposited sand into the new shallow seas.
I'm confused. I thought the Great Unconformity was worldwide. I was about to ask if there are places on other continents were it's visible. I've seen pictures of it in the Grand Canyon, Frenchman Mountain, and in the Rockies in Colorado and Wyoming, where there are exposures right by major highways. In fact, I think it's visible right by the road that goes to the airport in Payson, AZ. But that's all in North America. In any case, I thought the Great Unconformity was worldwide. No?
What kind of unconformity do you think the Great Unconformity is?
Nonconformity
It does not comply with uniforitarianism.
@@stevemiller1517 interesting thought. Tell me more about why it does not comply? And thanks for the comment.
I thought it had something to do with "Snowball Earth" ??? I am definitely not a geologist so please educate me if I am wrong 👍
Nonconformity
great video and if a person keeps driving along north shore road its considered the most amazing 40 miles of exposed geology in the world. I live in Vegas and I like hiking to and spotting "time zones and occurences" such as the great dying and we also have cretaceous just east of town as well. Also in frenchman mountain I will be looking to document that there must be alamo impact breccia in the layers roughly half way up from the comet/bolide impact that occurred north of Las Vegas.
That sounds like an awesome project. Please keep me posted and I would love to visit an impact site next time I am out in Las Vegas. I visited the shatter cones outside of Santa Fe and have a video in those if you are interested. Will link.
th-cam.com/video/4gVT-wErgy0/w-d-xo.htmlsi=q5BTvyciEpcHGktz
Thank you for the kind words and the comment. Excited to hear more about your research as you continue working on it!!!
@@earthandtime5817 thanks. I will be uploading various videos soon especially on cretaceous willow tank formation and other geology of the area. This is a new channel. My other one has 3,000 subscribers but had videos going back 2 decades so I started a fresh channel mainly for geology. I will also be going up Frenchman to locate the alamo impact breccia that reached the area. It would be roughly half way up.
I've been hiking there before and didn't know what I was looking at. Now I know. It's great to listen to you explain it.
@@joeoutabout2947 thanks for the kind words. It is a beautiful place. Hope to get back and do another video in the geology across the entire Frenchman Mountains.
as far as the uncomformity I am a believer that it represents snow ball earth time in which glaciers helped grind away alot of material which washed away
I actually don’t know much about snowball earth other then what I read about it as an undergraduate. I will need to read up on it. Thanks! Appreciate the comment and knowledge!
Yes! In at least one place in Wyoming in the Big Horn Basis just east of Yellowstone Park, the Great Unconformity exposes 2.8 billion year old Archean gneisses and granites with thinly bedded Cambrian limestones and shales of the Flathead formation deposited on a red granite that looks like it had been smoothed by giant grinder! Here the marine sediments may be peeled back to reveal rock last exposed to daylight more than 500 million years ago! That is evidence of ice sheet abrasion roughly 800 million years ago, .sometime before the supercontinent Rodinia broke up, later to join other fragments to become Pangea.
There used to be a set of nicely thought out informational panels set up at the Great Unconformity site and along the trail leading up the ridge. Frenchman Mountain as a whole is a remarkable geologic phenomenon, known sometimes as "The Mountain that Moved." The block that makes up Frenchman Mountain migrated some 40 miles from its eastern origin site over about a 2 million year period during the Miocene, leaving a trail of volcanoes and shear zones behind it. Unfortunately, those explanatory panels have been destroyed by vandalism, illustrating one of the hazards of trying to preserve and appreciate an urban unconformity.
Thank you for sharing. I read about the info panels and was bummed they were not there. I hope to get back to Frenchman and do a video about the stratigraphic package there and its structural history. Appreciate the extra info.
So much fun to check off our bucket lists. This was very interesting, thank you. Happy and healthy New Year to you and your family.
@@bluwtrgypsy happy new year. 🎆🎊. I hope you and your family have an amazing one! Thanks for being a regular commenter on the channel. I appreciate you!
Thank you ! My next trip to Vegas,Ill be checking this out . I did learn something :)
You are welcome and I am glad you enjoyed. Please
Let me know what you thought once back!
I'm about a mile away from that mountain. Dumping in that area is really becoming a problem.
Over time that dumping may fill in the missing billion years. And far into the future that will really throw geologists for a loop!
Thank you sir 🙏
Happy New Year friend.
Happy new year. I hope 2025 will be a great one.
Good presentation! Thank you!
You are welcome and thanks for the kind words.
Hi Garrett. I love to watch those old 1930's B Westerns that were filmed up in Lone Pine, CA. I've never visited, but find the Alabama Hills to be very interesting geologically. If you ever get a chance and can get up that way I would like to learn a little bit about how and why they were formed and their relationship to the nearby Sierras.
Thanks.
Thank you for the info. I will add the Alabama Hills to my list. I appreciate the kind words. Happy new year.
I enjoy content like this. We live in an amazing world/universe, and thanks to folks like you, I learn more about it every day.
The time scale of what you are showing, is mind blowing.
The geology tells part of the story, would love to know the rest, which make it a compelling mystery.
One of my own local geological places of interest is...
A section of cliff face, next to Lake Natoma, in Folsom California, exposed by erosion from the Lower American River.
I often see it on bike rides, as it is next to one of my favorite bike paths.
It has many layers of sediment including some with fist sized round rocks.
What I always wonder is, why such variety of texture, and how that variety got deposited there.
I assume it was put there by the river, but I don't understand why it changes so drastically in composition, and even vertical/horizontal orientation.
EDIT: I googled it, and learned a great deal about it. Fascinating. Your video inspired me to finally investigate 🙂
Best wishes for your continued success/fun with geology 🌎
So an old geologist here. After a quick look online it appears that at that unconformity in the Cambrian there were no land animals and little in the way of land plants. So what was the rock surface doing over the course of a billion plus years? Was it slowly eroding (of course it was)? Is there evidence in the lower metamorphic layer of differential erosion and stripping away of sediment? Are there erosional features to see? There is enough time for mountains to have built and then eroded to a peneplain during that time.
Today I drove past the Granite Mountains in the Mojave National Preserve. The rocks looked like those of Joshua Tree.
Good observation. I am not as familiar with the geology there, however there are a lot of granites in Southern California and it could be similar rocks! Thanks for the comment.
That area is always made me wonder. Looking on Google map the eroded sandstone jumps out at you. thank you.
It is a fantastic and beautiful place. Thanks for the comment.
For years, I've been hoping that someone would explain the coastal area between Malibu and the Oxnard military base, I get so excited when we drive through there, So. Cal.
Just stumbled upon your channel! Pretty interesting!
Anyway, have you been to see the Morton Gneiss in Minnesota, the oldest rock in the US? There's supposedly a display of it in situ at its namesake site of Morton, Minnesota. Of course, there might be some on some buildings in Houston and other big cities you've been to, since it's a popular decorative stone. Also, since I live in Seattle (which has at least one building clad in Morton Gneiss), I have to advise you to check out Nick Zentner's videos on Northwest geology.
While it's not as easy to get to as just driving down Lake Mead, the great unconformity in the Grand Canyon is much more pronounced. Thank you for a great video.
@@captdoug thanks for sharing and the kind words. Hope to get to the contact in the Grand Canyon someday!
@earthandtime5817 Just below Havasupai Garden, before you get to the Devil's corkscrew you'll cut through the tapeats and can stand with your feet on the vishnu schist and your hand on the tapeats.
@ thank you.
I’d like to know what the black spots are in the Tapeats. I have lots of samples I took from this location.
Great question. I didn’t take any samples. A thin section would be helpful. I was wondering if it is related to iron staining. I saw evidence for iron staining there.
I also put my hand on the Great Unconformity in the bottom of the Grand Canyon, the time involved in the gap is beyond our comprehension
@@peteklover2923 thanks for sharing. That spot is on my bucket list. I have been in the Grand Canton but I never visited the contact. Someday! Happy new year.
Snowball earth caused sea levels to drop and the ice ground down most of the land. Eventually new volcanoes emitted enough CO2 to warm the earth, melt the ice, cause sea levels to rise, then erosion of the remaining land deposited sand into the new shallow seas.
Thank you. I need to read up on snowball earth. Been since my undergraduate that I have thought about it! Thank you for sharing.
The dike has to be younger than the gneiss. Did it intrude into the Toroweaps Sandstone?
It is definitely younger. I did not see or read about it crossing into the sandstones. I believe the dikes are also in the billion year + range.
I'm confused. I thought the Great Unconformity was worldwide. I was about to ask if there are places on other continents were it's visible. I've seen pictures of it in the Grand Canyon, Frenchman Mountain, and in the Rockies in Colorado and Wyoming, where there are exposures right by major highways. In fact, I think it's visible right by the road that goes to the airport in Payson, AZ. But that's all in North America. In any case, I thought the Great Unconformity was worldwide. No?
Another reason it is "great" is because it can be seen all over the world.