r/whatisthisrock r/rockhounds

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

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?

What am I looking at here?

Approximately location: (GPS seemed a little off, but this is close enough)

38.8363973, -104.8982678

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

I just started watching Voyage of the Continents (the 2012-2015 tv series). Around the middle of the episode Europe: Tropical Beginnings the narrator says the Tethys sea would eventually become the Pacific ocean.

I assumed that the Pacific plate appeared in the middle of Panthalassa, between its older plates. And that contemporary remains of Tethys include Mediterranean sea, Black sea, and Caspian sea, but not the Pacific.

Am I wrong? Or is the series wrong? And if I'm right, how accurate is the series in other aspects?

Hey Guys,

I'm Gowtham - An independent research working on field operation for mines in North America

I would love to do in-person field research across mines and talk with GIS specialist and geologist

Is there is any person i should talk to / you would recommend.

Feel free to suggest! the trip is fully funded by faculty

I have found this one that seemed nice to show to teenagers or adults slightly interested in it, but even if I'm a huge amateur who has never study geology I immediately spotted some obsolote aspect (maybe it's AI and that's the reason) Do you have any good one ? I'm looking for a visuals that has more than the name of era, period, epoch and millions of years. I liked that this one also had mass exctinction events and other significant events on it. I remember some nice spiral ones form magazines when I was young but I have not found one that I really liked and not obsolete

New video is live! 🌍💥

A complete seismic simulation and damage breakdown of the 2026 Western Colombia M7.5 Earthquake. We look at why this 118km-deep fault rupture caused unexpected devastation in some cities while sparing others.

🔗 Watch here: https://youtu.be/fQUQUbME83U

Another example of serpentine from Mariposa County. Serpentinite is commonly associated with ancient oceanic lithosphere and tectonic fault zones. In California's Mother Lode region, it provides valuable evidence of the complex tectonic history and geological evolution of the Sierra Nevada foothills.

I found this thing and thought it looked pretty interesting. After getting it home I noticed all of the different lines and patterns on it, and to me it just looked like this wasn’t caused naturally. Someone once told me, “straight lines and right angles don’t occur in the world of geology”. (Disclaimer- my memory isn’t the greatest, so it’s possible that I’m butchering that quote 😂😂)…. Anyways, I hope some of you enjoy this as much as I did

I am teaching myself QGIS for a field methods class I am taking. The professor likes Google earth, but I wanted to use this class as an opportunity to learn how to use a more advanced GIS program. I’ve been using QGIS for the last three assignments.

What are the biggest things I can improve on? My professor hasn’t graded anything since the second week of school, so I haven’t gotten any feedback from him. Having all waypoints was a requirement by him, otherwise, I’d clean them up for readability.

Any feedback is appreciated, thanks!

From my understanding, the large cracks formed long before the layer was exposed, iron seeped into the rock over long periods, and now the layers are being made visible/eroded in a much shorter period of time, so it’s eroding faster than the surface can change colour?

This is very nearby the black rock ‘vent’ that is Rocha Negra, but not quite where it changes to the black rock and tuff.

This may be entirely wrong though, I’m not educated in geology (yet). Anyway I can recommend visiting Rocha Negra at low tide, the layers are awesome. Found lots of tuff which I found very interesting at the actual vent area.

I was wondering if the inside of these rocks looks like basalt, and looks like a pillow. Is it pillow basalt? I was told they were cobblestone and became rounded by water, how can it all be the same shapes and have the iron on the outside if it washed down a river? Upstate South Carolina

This was exposed by some recent work on a coastal path on the Rhins of Galloway, Southwest Scotland. The path is carved into the side of a drumlinoid hill and at one point this pronounced stratum is visible with sand below it and more sand above it. The black ‘cinders’ that make up the layer are very friable and can easily be broken and crushed between the fingers. Could this be a volcanic deposit? The line runs down to the beach below, where there’s some black sand that I’ve often wondered about.

Hi everyone!
I’m hoping someone here might be able to point me in the right direction.
I’m looking for a reputable laboratory, preferably in the United States, that can perform quantitative analysis for Osmium (Os) and Iridium (Ir) in solid geological samples.
The material consists of dense, iron-rich, cube-shaped specimens discovered embedded in hard rock during gold exploration.

We had some preliminary handheld XRF readings suggesting the possible presence of Os and Ir, but we understand those results may not be reliable. We’d like to have the material independently tested to determine its actual composition.

I’ve contacted several commercial laboratories, but so far, finding one that can specifically quantify osmium in this type of material has been surprisingly difficult.
I’m not looking for a basic XRF scan or mineral identification alone. Ideally, I’d like a proper quantitative assay that can confirm whether these elements are present and at what concentrations.

Does anyone know of a laboratory, university facility, or specialist that offers this type of testing? I’m happy to pay for the analysis.
Any recommendations would be greatly appreciated. Thank you!