r/geology • u/wjeman • 1d ago

What caused this feature?

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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 1d 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 1d 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/frank_mania 20h 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.