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 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!

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

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

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!

Good evening all.

I joined this group to ask a question. I live in an area where (nearby) is a perfectly round and shallow lake. It's interesting because local legend suggests that it wasn't always there and the name of the place in the native language means "landing place"

What could I do to search for evidence that it was Indeed an impact crater?

I'm researching the geology behind the famous pre-Columbian stone spheres of Costa Rica, and I have a question about the raw material.

Most of the large spheres were shaped from hard igneous rocks, including gabbro and granodiorite. But before considering how people worked these stones, I'm interested in a more basic question: how rounded might some of the original boulders have been before any human shaping?

In a hot, humid tropical environment, could spheroidal weathering of jointed igneous rock produce large, naturally rounded corestones that might later be selected and worked by people?

And what field evidence would help distinguish spheroidal weathering from river abrasion or other processes? Would weathering rinds, fracture patterns, mineral alteration, or the surrounding geology be the most useful clues?

I haven't found a published study establishing spheroidal weathering as the source of the Diquís sphere-makers' raw material, so I'm interested in what the geology can actually support—not assuming the hypothesis is correct.

I'd appreciate any geological references or insights, particularly from people familiar with tropical weathering and corestone formation.

Link: I Investigated the Costa Rica Stone Spheres. The Answer Surprised Me

Edit: there may be some confusion about what the photograph is showing — that's not a photo of a Costa Rican sphere, but rather a natural boulder at the Cansót site, which is highlighted in the text.

Here are some photos of Costa Rica sphere: https://cdn.nexusnewsfeed.com/images/2022/3/Diquis-Delta-1649337177079.pnghttps://www.grunge.com/img/gallery/the-mystery-of-the-stone-spheres-of-costa-rica/intro-1597089160.webp

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.

Molten rock may carry an oxygen reserve that standard chemical calculations overlook. High-pressure experiments show that basaltic melts exposed to oxygen-rich conditions can retain substantial extra oxygen, potentially adding a missing component to models of Earth’s interior.

The study in National Science Review combines laboratory measurements with atomic-scale simulations. Yanhao Lin and Ho-Kwang Mao of the Center for High Pressure Science and Technology Advanced Research, known as HPSTAR, led the work with collaborators. The team included Haiyang Niu of Northwestern Polytechnical University and Wim van Westrenen of Vrije Universiteit Amsterdam, with Yongjiang Xu as first author.

The results raise a larger possibility: some rising magmas could transfer oxidizing power from deep reservoirs toward the surface. Establishing that capacity, however, is different from demonstrating how much oxygen natural magmas actually carry or release.

I understand the rocks can split but this looks like a chunk was taken out and it looks like a perfect split. But the other lines and cracks in the rock aren’t not perfectly straight. Is this natural or human made?

A clip from my volcano comedy special, here's the full show: https://www.youtube.com/watch?v=72IwnxnejfE

Greetings friends. I am an economist by education and have come here with a question regarding geological reserves. I live in South Africa. I'm familiar with the fact that South Africa via the Bushveld Igneous Complex contains the worlds majority of Platinoids (Platinum, Palladium, Rhodium, Ruthenium, Osmium, Iridium). However after reading abit about the geologist Hans Merensky there was a mention of Gold in the Free State province. So what is the official geological data on amounts of gold reserves in the Free State province? Thanks for your feedback comrades

Link: https://www.geoshow.rocks/game

Hey everyone! I made GeoShow: Curse of the Golden T. rex, a browser-based geoscience game for my students. It’s a 2D mining adventure where you explore a mountain, uncover fossils and minerals, and upgrade your equipment. You also need to manage your food and backpack weight.

The learning is tied to the gameplay: when you discover a fossil, you identify its type and place it in the right geological period. The accuracy affects what the museum pays you, so knowing your fossils helps fund your next expedition. I’ve also added a global leaderboard, so the competition can go beyond my clasroom.

I’d love to hear what people think!

While exploring the Italian landscape with daevorn-maps, I came across this hill not far from Mount Amiata, which has a curious pockmarked surface. I’m not sure whether these are boulders or holes, but in any case, the pattern seems far too regular to be a natural formation.

Mount Amiata is a Pleistocene volcano, so this could be the result of volcanic eruptions.

Does anyone have any ideas or explanations?

Thanks!

My mother first noticed these when I was a kid, but had no idea why they were this way. It wasn't until I got some geology education, and learned about the joints in my area's bedrock that I figured out the cause. Joint orientations vary, but it's fairly common to find orthogonal or nearly orthogonal joint sets.

Garnet in Limestone. So we are having drilling exploration in the limestone terrain and we found garnet patches on limestone. What could be the reason ? The terrain is of Granulite region as the basement rock but we are yet to hit the basement rock ?

In 1877 Grove Karl Gilbert, a geologist with the Powell Survey, passed through and recognized this ridge of gravel as a giant sandbar built by a lake that no longer exists. Waves and currents on Lake Bonneville piled it up in the strait between South Mountain and the Oquirrh Mountains.

Three years later he came back with the U.S. Geological Survey and mapped it in detail as "The Great Bar at Stockton, Utah."

This is my own render of the bare-earth lidar. The bar is the long curved ridge running from the left edge to the middle, where a road and rail line cross it.

1. Bare-earth lidar: the Stockton Bar curves in from the left edge
2. Air photo of the same area, October 2021

Numbered pins on picture 1:
Pin 1: Crest of the Stockton Bar
Pin 2: Road and rail cut through the bar
Pin 3: A quarry pit in the bar

Lidar: USGS 3D Elevation Program (3DEP), public domain.
Imagery: USGS The National Map (NAIP Imagery service), 2021, Public domain.