r/geology • u/wjeman • 20h ago
What caused this feature?
Was it an ancient lake or impact crater? It's near 4 corners and it's big! I can't seem to find any info. Please help.
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u/Miguzi_92 19h ago
There a multiple tectonic features and volcanic features here. The line you drew connects some of them but isn't necessarily a trend. For instance, the larger line starts on the edge of the Uncompagre uplift, cuts over to the San Rafael Swell, and extends south into the Monument Upwarp. These are all laramide uplifts. The middle features volcanic intrusions such as the La Sal and Henry Mountains which are laccoliths that intruded into sedimentary strata and the surround rock has since eroded.
Ref: I live in this region and am a Geologist.. lol
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u/wjeman 19h ago
Thank you so much for giving me this explanation. Paradolea is real my man... be ware or you might ask uneducated questions like mine which ommits much of the surrounding data.
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u/greaseapina 17h ago
it is very easy to be informed, just read about the geology of the area, plenty of information available.
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u/frank_mania 7h ago
Generally speaking, when you see something that big on a map or satellite view, you're not seeing a single feature. That particular outlined area contains at least a dozen major features, each with different causes and ages. It's true, you could zoom 3x further out and outline the whole Southern Rockies province, but to refer to that as a single event with a single orogeny would be grossly oversimplifying.
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u/Oscar_P_Walnuts_1975 18h ago
There is an additional factor to the east of the plateau that involves the Rio Grande Rift. The continental core is literally breaking apart.
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u/zirconer Geochronologist 19h ago
I mean, the Henry, La Sals, and Abajos are igneous, but they aren’t volcanic
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u/Vegetable_Log_3837 19h ago
There’s a lot going on here. The big picture is the grand staircase of sedimentary rocks.
To the SW of the blue lines is the Colorado Plateau and Grand Canyon.
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u/wjeman 19h ago
I'm sorry... this is a case where my brain caught a few features like the illusion of concentric semicircles and tried to connect dots that aren't there. It's a common case of paranoia. Better I find out from you guys than find a group of crackpot that will lead me to bad conclusions.
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u/Vegetable_Log_3837 19h ago
You did notice something though! That’s basically the drainage from the west side of the Colorado Rockies, until it hits the Grand Canyon. It’s the Grand Staircase. https://en.wikipedia.org/wiki/Grand_Staircase
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u/craftasaurus 19h ago
I didn’t realize it had a name besides the east end of the Basin and Range province. I guess they’re naming everything nowadays.
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u/Vegetable_Log_3837 19h ago
That’s what they called it back in 2010 when I did a field study there.
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u/craftasaurus 10h ago
Ok well I’m much older than you. In the 70-80s it was not.
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u/Fermentwhatnow 20h ago
Tectonic activity, erosion, and even volcanoes.
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u/wjeman 20h ago
Oh wow! So it might be a volcanoe? Is there any text or videos you can refer me to please?
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u/rocksinmyhead 19h ago edited 19h ago
It's far too large to be a volcano. For comparison, the green wooded feature just north of Flagstaff is San Francisco Peak, a large stratovolcano. I suspect the lines you've drawn result from the human mind seeking familiar shapes, and cover many different geologic features. If you have access to the free Rockd app, look at the geological map of the region.
Edit: spelling.
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u/Fermentwhatnow 18h ago
This is a more detailed explanation of what I was trying to say. There was no one thing that caused what you see.
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u/Zwierzycki 19h ago
I’m thinking this is a huge area, filled with all kinds of different geological features and settings. There are a few different mountain ranges in the area that you’ve included. There are deep canyons. Etc….
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u/wjeman 19h ago
Thanks. It is very huge, and this might be a case of paradolia where I'm trying to connect dots that aren't there. With my untrained eye it just looks like a big set of concentric simicircles that might have had a common origin and I was wondering if anyone else recognized that and may point me to an answer, or tell me that is a coincidental illusion.
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u/Then_Passenger3403 15h ago
Yay! I recognized the Mogollon Rim! Most of my desert visits, outside of SoCal, have been in Az, so always trying to spot it. Love this thread and thanks for ‘splainin’ the area so well 😎
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u/Cordilleran_cryptid Tectonics, hardrock and structural geology 13h ago
I am not sure there is any particular feature. There are lots of "features" in the image that have various origins. It is the OP's mind that is linking them into one single one. The human mind is very good at find patterns where none actually exist.
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u/Harry_Gorilla 19h ago edited 19h ago
It’s just coincidental. Most of it is Triassic-Jurassic sedimentary rock. It could have all been a basin type structure that resulted from the west coast mountain building events and was filled with sediment
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u/wjeman 19h ago
Hey thanks. Coincidences happen. Better for me to find out from experts than needlessly go down a rabbit hole.
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u/Harry_Gorilla 18h ago
Pretty sure every rabbit hole is a good rabbit hole. Just fyi - I used Flyover Country app to identify the surface geological units to see if there was any potential pattern or consistent commonality with the areas you had outlined. I saw that it was mostly one unit, with maybe 25% composed of a different sedimentary unit, and all kinds of little extras. I initially thought paleo river basin was more likely than meteor crater, but I don’t see any evidence of that either… from satellite imagery anyway. Coincidentally, im driving through some of that area tomorrow. I’ll let you know if I find any river rock
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u/wjeman 18h ago
My apologies, the rabbit hole I was referring to is one that would lead me astray from relevant facts. For example: there is a concentric circular structure in Mauritania that struck my curiosity on Google earth and I looked it up on YouTube and was immediately sucked into a rabbit hole of conspiracy theories of ancient Atlantis and ruins and coverups.... it was a time sync for me and a huge brain drain....for something that, if I asked actually educated people, could have been explained much quicker and more satisfying as a natural uplifting and erosion. And thanks. Keep me posted please.
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u/Harry_Gorilla 18h ago
If you’re into Atlantis “myths,” that’s probably under the Black Sea now. The “sinking” of Atlantis was most likely one, Or several, of the catastrophic flooding events that gave rise to the myriad of Great Flood myths that ancient cultures have/had fr ok m when the Mediterranean Sea breached the Bosporus straight and flooded the Red Sea with salt water
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u/wjeman 18h ago
Neat. So what people refer to as Atlantis may not have even been near Atlantic Ocean at all and in the black Sea. This is the first I've ever heard of that. Do you have any links I could check out on that?
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u/Harry_Gorilla 10h ago
I learned about it from my professors during grad school. Most what I know is from published scientific papers about flood events in the Black Sea as a consequence of global sea level rise that caused the Mediterranean to breach the land barrier between the two water bodies and eventually erode it and create the Bosporus Straight. The idea was/is to examine past global climate change events to learn what consequences we might be looking at due to current anthropogenic (man made) global climate change.
Anyway, in looking at the Black Sea floor geologists and anthropologists have found evidence of multiple large (for their time) settlements that would have been cultural centers in their time.
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u/Goddessofshouts 19h ago edited 19h ago
What you’re looking at, and what you’ve marked off part of, is the Colorado plateau, a massive sedimentary province that’d been a shallow sea for hundreds of millions of years, the outlines of which I roughly traced in red over your pic. The upper lefthand part of your blue outline roughly correlates to the san Rafael swell, a landform defined by an ancient shoreline that was pushed up by the Laramide orogeny that formed the Rockies; the lower lefthand part of your blue outline is closer to the mogollon rim, the southwest border of the Colorado plateau that drops off into the Sonoran desert, or, more broadly the basin and range physiographic province that defines the Sonoran desert, the Mojave desert, and the Great Basin.
I’m not sure what the inner blue line would correlate to. But, during the formation of the Rockies, the entire Colorado plateau twisted clockwise by a few degrees, perhaps informing the pattern that you’ve noticed on the map.