Slates from Mariposa County 🛘

I’m posting this to show some tile “trash” some folks were throwing out. I cannot fathom why they would! Look at these layers. It looks like a microcosm but literally a landscape.

How long did this take to form? I assume it’s from a slow build up of run off sand in our rare rains (I’m a desert rat)

Ok but also I just wanted to share the beauty of these. Hope everyone has a great weekend

Found this slab laying on the shore of Lake Michigan (WI) and I was curious to know what caused these gouges. My best guess is glacial scouring but the multiple directions makes me think perhaps not. I’m not even close to a professional so sorry if that guess is silly! I’d love to hear some thoughts on the origin of these marks.

Looking to see if this is safe for aquariums and any pictures of this rock to see if its the one i have. Thanks

Good afternoon!

We haven't announced it anywhere, but r/whatisthisrock (with an I in is) is no longer affiliated with r/whatsthisrock (no I in is)!

Myself and some of the OG mods from the original sub spooled it up as an alternative to the original with less intense moderation. None of the bans from the original sub should carry over! If you are currently banned our our sub (the photo is an olivine in xpl from a meteorite), please send myself or the moderation team a message.

We could definitely use some more professional IDs!!

Hi,

I am developing an engine that simulates deep-time landscape evolution from first principles (combining stress-driven brittle/ductile crustal deformation, multi-layer lithology, and fluvial/gravity transport).

Rather than generating standard visual heightmap fractal noise, the pipeline uses multi-layer 32-bit raster strata stacks (mapped in Krita as discrete compositional layers with individual silica/carbonate/clay fractions and mechanical rock states: regolith, sedimentary, metamorphic, magma). The engine translates these layers into a 3D volume, accumulates tectonic stress until it exceeds failure criteria (Byerlee's law), and routes surface/subsurface weathering based on differential lithological resistance.

"I’m currently calibrating the physics for this simulation and want to make sure the structural behavior is scientifically grounded."

some quuestion I would like answered are

1. Differential Weathering & Dip Slopes: In the stepped terrain slices, does the scarp-and-dip geometry convincingly reflect what you would expect from alternating competent/incompetent strata (e.g., sandstone vs. shale beds undergoing tilted block faulting or homoclinal shifting)?
2. Drainage Realism vs. Structural Control: In the central valley between the two main massifs, does the channel incision look like genuine antecedent/subsequent drainage capturing fault lines, or does it look too artificial/regular?
3. Talus & Angle of Repose: In the high-relief peaks, the scree/avalanche slopes are driven by friction angles based on rock state. Does the slope angle and valley wall steepness look physically defensible for crystalline/metamorphic basement rock under rapid uplift?
4. Missing Mesoscale Features: What key mesoscale structural or erosional landforms (e.g., flatirons, knickpoints, specific colluvial apron behaviors) are noticeably absent that would immediately break your suspension of disbelief?

Any critical observations or suggestions for physical tuning will help refine the physics for the simulation

Looking for reviews/suggestions about any of the winter field camps from SDSMT. The Hawaii trip piqued my interest, but I’m open to Death Valley or Arizona. I’m not very skilled when it comes to mapping, which I understand is pretty much the point of field camp, so I’m very nervous.

The SP stands for Shitpot :D

Hi guys! Lately, I've been fascinated by extreme underground structures and ended up researching the Kola Superdeep Borehole again. It’s crazy to think we’ve barely scratched the surface of our own planet, even with all our tech.

I wrote a quick piece summarizing the journey and the strange conditions they faced at that depth: https://www.lyxplanet.com/kola-superdeep-borehole/

For those who love deep underground anomalies, what do you think is the wildest thing hidden beneath our feet?

Hello everyone, I am currently a Geology major in University and I just had my mineralogy midterm yesterday. As one does after an exam, I looked through my notes to see how I did on the questions and I don't feel as confident as I did when I first finished the exam. I may have either barely failed or barely passed. I've heard that mineralogy is a difficult class, is this a normal experience? Its not worth a crazy portion of my grade so its not as if I am going to fail overall, but I studied super hard and I thought I would do better. Any advice?

A few monts ago i made a travel to a park where one of the places had a big formations of compressed sand that had a texture like sandpaper, in one of the formations it had a strange red line that got me curious since then, i hope someone here can help me to even get a starting point to investigate this.

PS: I´m gonna leave some extra photos of the place at the end.

I think I might have found a one of one, or at the very least a very rare finding at herkimer, I can’t find any information online or in any other forums whatsoever, as well as the fact that google AI claims this is impossible to find at this locality but clearly it isn’t since this is proof

I live in South West England, where the coastline is typified by cliffs of typically 30-100m asl.

Offshore the bathymetry doesn’t exceed 100m until you get a long way offshore, and the sea bed is broadly flat in most areas.

My understanding is that sea level during the LGM was up to 120m lower than today. So what did the coastline look like then? Was there a wall of cliffs where the current coastline is, several miles inland, surrounded by lowlands to the contemporaneous sea? Or has the cliff line been eroded that many miles inland during just 20-30,000 years?

r/whatisthisrock r/rockhounds

I saw these limestone blocks in some landscaping. There wwre these inclusions in the limestone that look like they were filled in holes. They were circular, so it looks like they might be filled in has bubbles. Am I thinking about thos right?

Glacial till and stratified drift exposed on the north shore of Long Island, New York after the Sept. 26 noreaster

You can play it there: https://gesla.itch.io/silt-inquiry

So far, there is only one level. I would like to add Raman spectroscopy later. I tried to make this fun but I wonder how unrealistic it is and whether I made mistakes. Thanks

Hey Everyone, this google earth image is taken in Rural South-East Queensland, Australia. These streaks are a few hundred meters long, and 5 - 25 meters in width. They seem to go in low areas/ go from a top of a hill down it, but not exclusively.

Is this quartz? sand? just water paths? Old river beds?

Would love to know what these are, and what causes the colour. Sorry if this isn't the right subreddit.

Thanks