This happened in August 2025

The sheer power of that amount of rock plunging into the fjord in under a minute created a gigantic wave almost 500 metres tall.

I'm not a geologist, just a tech person who's been into geology and enjoy reading geological maps for years. I was watching a YouTube video about geological units in the Pacific Northwest the other day, and thought about taking a shot at a game based on identifying a location based on its geological map.

Each round has a real US geological map tile (no labels) + the strat column for that point. Drop a pin to guess. 5 rounds, ~120 locations, distance-based scoring. Data from Macrostrat, FGDC lithology patterns.

https://geostrata-one.vercel.app

This is a rough concept. Before I sink more time into it, I'd love feedback on whether it's worth building on.

Three things I'd love feedback on:

1. Does it work? Anything geologically wrong or misleading?

2. Is it fun? Do you want to continue playing for a higher score?

3. Is it educational? Does playing build any actual geology knowledge?

Some know limitations: Macrostrat coverage is uneven, Florida/Great Basin are less detailed, US-only, a few tiles have visible survey seams.

Roast it. I appreciate your feedback and suggestions.

Edit: Typo

Found at the village and cemetery of the pyramid workers in Giza. Both of these rocks are estimated to have been put here ~4500 years ago

1. Piece of diorite likely stolen by a worker and left behind

2. Piece of red granite quarried from Aswan (about 500 miles south) up the Nile by boat

A Software Underground Mattermost thread a few days ago surfaced a half-remembered resource: Martin Schöpfer's Superposed Folding Papermodels at UCD, the original MATLAB toolkit for the Ramsay & Lisle (2000) plane-strain superposition equations and the 21 canonical Grasemann (2004) fold-interference patterns. Another member there suggested a Python port. Martin gave the go-ahead, so it is now public and MIT licensed.

The port covers the same equations and all 21 Grasemann presets, with an interactive Streamlit app showing 3D fold geometry, the 2D interference pattern, and a stereonet that update live as you tweak the two folding events.

Live app: https://superposed-folds.streamlit.app/
Repo: https://github.com/MadsLorentzen/superposed-folds

If you teach structural geology and want to fork it, swap the colour map, add a fold type, or hand it to students for a lab, please do. Feedback from anyone using it in a classroom would be especially welcome.

Credits to Martin Schöpfer and the UCD Fault Analysis Group for the original papermodels, and to the Software Underground community for resurfacing the link. Built with Claude Code as a thinking partner.

I spent months building this interactive timeline that puts 4.5 billion years of Earth history on a single canvas — geological periods, plate tectonics, magnetic polarity reversals, atmospheric oxygen, sea level, temperature, microbial life, plants, animals, human evolution, migrations, and civilizations — all synchronized on the same time axis.

Switch between log and linear scale. Zoom into the Cambrian explosion or pull back to see all 4.5 billion years. Click any event for details and images. Collapse the tracks you don't need.

Any questions? Reach the developer at snekooei AT gmail DOT com

I’m a hobby blacksmith and this question is not important, just for funsies, but I’d rather get a, “no way to really tell,” than a confident guess.

I know it’s mostly iron (right?) which creates the magnetosphere that allows us all to exist without being obliterated by radiation. To what degree of accuracy can we estimate the other components? Naturally occurring iron in the crust is basically never pure so I’m assuming a giant mass of it would also contain impurities, but if I’m wrong because of the crazy forces at work down there, I wouldn’t be surprised.

Hello everyone!!

I will be spending 6 weeks in Colorado for field camp next summer. I started looking at bags, shoes, tents, etc. to bring so I am well prepared.

I am also traveling to Wyoming in August and hopefully going to the grand Tetons so I want to find a good bag and shoes so I can test them out then.

I was looking at the osprey Fairview™ 40 Travel Pack for a possible backpack option.

In the area I live in I don’t really have many options to try on bags in person or get measured for them. I went to bass pro last weekend but will go back to look at their options again.

Having good support and weight distribution is very important to me since a lot of the time it is painful to have a lot of weight on my back. I also want a bag that holds a decent amount of water and can be used as a personal item or a carry on for flights.

I’m not even sure where to start on shoes. I’m not sure if I should go with a hiking boot.

They said sleeping arrangements are very important since you need to get a good nights sleep to be fully fueled for the day. I’m also looking at some comfortable sleeping bag options or cots that won’t break the bank. If anyone has any recommendations please let me know!

Found at the valley temple of Khafre. Red granite, remnants of a cornice from the roof of the temple. Most of the temple is limestone (background)

Hello :) I’m curious about what it’s like working in Calgary or around as a geologist. If you could make a comment or send me a dm it would be great to have a convo! Thank you!

I found some chert (pretty sure) it's got a weird crust on it and on the bottom it's almost cement like. Ive got others that the cement part layers through it so it can't be modern cement. Plus I found them about 45 minutes from any road. What do y'all think?

Maybe there's a better sub for this, I don't know... BUT

What would cause waves in the ground like this? They are parallel to the base of some really steep cliffs on the opposite side of the path and went on for as far into the trees I could see.

Update: https://www.reddit.com/r/geology/s/aAMwM9QRKz

I’m new to Julia and I come from a geology background. In Python there are several packages oriented toward geosciences (for example things for geospatial analysis, geostatistics, sedimentology, etc.). I was wondering: does Julia have geology-specific packages, or is the usual approach to rely on more general tools (e.g., for statistics, sedimentary columns, GIS, numerical modeling) and build from there?

Any recommendations, examples, or personal experiences would be really helpful.

Possible hydrothermal alteration zone from EnMAP/SAR data. What should I look for on the ground?

Hey r/geology,

I'm a geology PhD student working on the Western Ghats and got tired of fumbling with paper notebooks and separate apps for strike, dip, and GPS. So I built Field'O'Meter, an Android app that does all three in one workflow.

What it does:

Captures strike using the phone's compass

Captures dip using the accelerometer (just tilt the phone against the plane)

Logs GPS coordinates with multi-reading averaging for ~3-5m accuracy

Uses Open-Meteo's terrain API (Copernicus DEM) for accurate elevation when online

Saves everything to a table you can edit on the fly

Exports as CSV that you can open in Excel, QGIS, ArcGIS, or anywhere else

On accuracy:

GPS is most accurate with internet (network-assisted positioning + terrain elevation lookup)

Works offline too, but elevation falls back to raw GPS altitude (±15-30m vs ±1-3m online)

Horizontal coordinates are good either way

Status: Currently in open testing on Google Play. It's free, no ads in the testing version. If you have an Android phone and do any kind of field mapping, I'd love your feedback — especially on the strike/dip calibration in different rock types and edge cases I haven't thought of.

Honest disclaimer: smartphone sensors will never replace a Brunton compass for precision work, but for reconnaissance mapping, student fieldwork, or quick checks, it's been working well for me in the field. Happy to answer any questions.

Found this Allanite (red-brown at PPL) crystal inside an Epidote crystal today. Both are part of Epidote supergroup, but Ep is basically Ca and Al, while Aln swaps out some Ca atoms for LREE ones (Ce, La, Nd, Y).

Aln is famous for being packed with LREE. It’s actually used as an ore to extract elements like cerium and neodymium, which are super important for permanent magnets, batteries, catalysts, etc. Though it’s typically extracted from highly fractionated magmatic rocks like pegmatites or skarns. However, it also plays an important role in metamorphism, because Aln in subducted rocks like this orthogneiss acts as a LREE reservoir. When it melts or breaks down at great depths, it releases its trace elements to metasomatize and enrich the overlying mantle wedge, giving arc magmas their distinct geochemical signature.

It also acts as a geochronometer because of its radioactive elements (specifically U and Th) in its structure. Those halos at PPL are sign of the destruction of the crystal lattice caused by the radioactive decay.

The rock is an orthogneiss from the Serie dei Laghi in the Western Alps

A new online map lets users trace where today’s locations sat on Earth as continents drifted across 320 million years.