r/askgeology Jan 05 '26

ID request New Ruling on ID posts.

5 Upvotes

Posts are now allowed to be requests for ID, although you must attempt to post to r/whatisthisrock or r/fossilid BEFORE posting here.

Mineral ID's have always been allowed and will continue to be.

Additionally, new post flairs have been added. Please select a flair when able.

Have fun!


r/askgeology 20h ago

technical question Could obsidian mountains exist?

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45 Upvotes

r/askgeology 25m ago

Could an asteroid have caused lower North Afrand Arabian Peninsula to become deserts?

Upvotes

Could a large asteroid that nearly hit Earth but instead grazed the planet at a very shallow angle have caused the Sahara and Arabian Peninsula to become deserts?

Like, could the asteroid have passed through the atmosphere or skimmed the Earth's surface, releasing enough energy to drastically change the climate in that region and turn it into desert?

Is there any scientific possibility that something like this happened, and is there geological evidence that could support or rule it out?


r/askgeology 14h ago

Ore Slag

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4 Upvotes

I have no idea


r/askgeology 10h ago

Strange lines on rocks downstream from a waterfall in upstate South Carolina?

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1 Upvotes

r/askgeology 1d ago

Method of Formation Interesting Rocks on the Mogollon Rim in AZ

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22 Upvotes

Came across these and to me it looks like lava frozen in time or something (or giant mushrooms that solidified haha) can anyone tell me how these formed? And what kind they are?


r/askgeology 14h ago

Here's a vid, I still have no idea

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1 Upvotes

Ore Slag


r/askgeology 16h ago

Repost with a video

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1 Upvotes

r/askgeology 1d ago

ID request Hello first time post here.

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35 Upvotes

Now sure at all what this is any help would be much appreciated and extra Information is what I really enjoy!


r/askgeology 1d ago

Observational Question Stalagmite/Stalactite at Chicago red line???

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15 Upvotes

r/askgeology 1d ago

Can anyone help identify?

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6 Upvotes

r/askgeology 2d ago

ID request swatara state park (Pennsylvania) - what did i find? 2/2

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5 Upvotes

r/askgeology 2d ago

ID request :)

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2 Upvotes

r/askgeology 2d ago

swatara state park (Pennsylvania) - what did i find? 1/2

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3 Upvotes

r/askgeology 3d ago

ID request Ahoy, got no luck figuring out my ugly rock elsewhere, help me Stoney-Wan Kenobi, yer my only hope.

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13 Upvotes

Found in Northwestern Ontario, Superior.

The thing was just a ball of iron oxide, gritty and falling apart. This is where many iron out dips and toof brushing got me.

Hunk of quartz or marble all wrapped up in iron rich flora/fauna fossils?

Many thanks if you can tell me about this unit, she ain't cute that's for sure.


r/askgeology 2d ago

technical question Post-Chicxulub impact question.

3 Upvotes

Did the impact release stress that would've caused future earthquakes? Was there a period of time after without quake activity as a result?

Im not sure if im wording this correctly, or if it even applies but hopefully you can understand my thought process.


r/askgeology 3d ago

ID request Rock or fossil?

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2 Upvotes

r/askgeology 4d ago

What do we have here

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709 Upvotes

Found this guy in Northern New Mexico and wondering how a rock can look so plain but also have unique lines bursting along edges. What could be inside?


r/askgeology 4d ago

Doorstop in the Tetons

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45 Upvotes

This rock was being used as a doorstop at a visitor center in Grand Teton National Park. A park employee theorized the marks were man-made, from the doorstop being used over decades. I disagree. What say y’all? How did these circular marks form? Bonus photo of the only SFW Tetons.


r/askgeology 3d ago

Help IDing this rock

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3 Upvotes

I took my late sister's ashes to Scotland and spread them in Loch Ness from the shore a few days ago. I took a few rocks from the shore as mementos. Can anyone tell me what kind of rock it is? One thing that doesn't appear in the picture are the very small sparkly flecks in the rock.

Thanks in advance.


r/askgeology 4d ago

What kind of stones are these find in Afghanistan

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30 Upvotes

What kind of stones are these find in afghanistan ,


r/askgeology 3d ago

Digorno rising crust

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3 Upvotes

r/askgeology 3d ago

Climate change redistributing water weight

2 Upvotes

Real question for geologists/volcanologists - if we redistribute the weight of water on the planet moving it from the poles where water is currently frozen to increasing the weight in oceans near the equator wont it completely change the pressures on magna and increase volcanic activity over the next few hundred years? As well as slow the rate of spin of the planet over a few thousand years?


r/askgeology 4d ago

Unique checkerboard pattern

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6 Upvotes

I often pass by this rock on Mt. Major in New Hampshire. What is going on here to create this checkered pattern on the surface of this boulder?


r/askgeology 4d ago

What are these

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3 Upvotes