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Questions tagged [geology]

The science comprising the study of the rocks Earth is composed of, and the processes by which they change. Some subfields of geology are petrology, mineralogy, and geophysics.

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What has formed this rock and its colours? [on hold]

I found this rock in Oregon as a boulder in the countryside. It almost looks like a cut of meat in pattern with white crystal look and pops of lavender it weighs about 25 lbs
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Can someone identify these dark red rocks?

It has pretty even color - dark red rock with white snowflakes all over it. I found it in MA, near lake, where water seems to wash out the shore. The main block was too big to take (but I saw it), so ...
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why igneous phosphate rocks contain less uranium than sedimentary rocks?

Sedimentary rock phosphates contain much higher concentrations of potentially hazardous elements (As, Cd, Cr,Pb, Se and U)than igneous rock phosphates. Why? Is it because U concentration in magmatic ...
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Need help identifying rock formation

so this is my first time here because I need help in identifying the features on this rock formation. https://www.flickr.com/gp/158064920@N05/6USrY9 Thank you in advance.
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What clays from XRD analysis should be taken into account in Vshale calibration?

I'm working with Well Logs and I want to calibrate my Vshale model with the clays from an XRD analysis that I have from the lab. There are muscovite and biotite, chlorite (secondary), detrital clay ...
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1answer
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When will the weight of melted polar ice release the (currently stuck) subduction of the oceanic plate West of the Oregon coast?

Melted polar ice water makes the oceans deeper on average. The extra water on top of the oceanic plates makes them sink relative to the continental plates. This relative vertical displacement will ...
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Why are there no deep caves in the continental US?

According to http://www.caverbob.com/wdeep.htm and http://www.caverbob.com/usadeep.htm, the only cave over 1000m deep in the US is a lava cave in Hawaii. In the continental US the deepest is 505m. On ...
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Rock type identification

Found this rock in western Ireland among many other like this one, its scratch resistant to a stainless steel blade, its blackish with light green spots and some tiny Pyrite crystal inclusions, it ...
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Formation of Hematite on Mars via Perchlorates as an Oxidizer

Hematite on Mars is generally thought to have formed either in pools of water or from volcanic activity. A comment to the answer to the question: How do hematite and magnetite form? states that ...
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1answer
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Brown rock with hollow black interior?

We found a brown hollow rock in the woods in Sabine Parish, Louisiana , US. The tip of the rock had broken off, exposing the inside which is a black shiny rock. Someone told us that it may be a ...
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1answer
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Do there exist reasonable numbers on the density/radius/mass of the various geological layers of the Earth?

I've been doing some math on the radius of the core (inner core in particular), and I keep getting what look like nonsense results. The composition is supposedly nearly all iron, close enough to it ...
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1answer
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Carbonaceous Chondrite [closed]

Can you please help me identify this rock? Is it a meteorite; if so, what kind? I sought the advice of the only scientist I know, but geology is not his primary field. He suggested a mineralogist ...
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Rock identification: Black mineral with quartz streaks

This rock is just under 2 inches, weighs 2 ounces and has a smooth feel to it. It has some milky quartz streaks and some black mineral that's moh's hardness of 6-7 (tested with steel pin scratch test)....
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1answer
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What is diffuse plate rifting?

For example in the Philippine Sea Plate the West Marianas Ridge has formed due to diffuse rifting in the south of the Marianas trough. What does it mean?
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1answer
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Identification: mystery rock with golden features and shimmer

I found this rock in our backyard in Germany. As our garden is filled with bushes it was very oddly placed and I have carried this rock around with me ever since, wondering what sort of rock it might ...
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1answer
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What is this rock. Solid, Heavy, Metallic. Unknown origin

A few weeks ago i found this rock in the geology collection cupboard that my Geography teacher inherited from his predecessor. It is numbered 3729 but no list exists of the collection so we can not ...
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Which is naturally more radioactive: a tertiary or cretaceous sandstone? Why?

I've come across this question in a Petrophysics exercise regarding the Gamma Ray well logging. And I don't know how to solve it. This is the "believed" AFAIK session Natural radioactivity on a ...
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1answer
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Identify yellow-tinted translucent mineral

I found a mineral near the hexagonal rock formations in High Island, Hong Kong that I'd like to get ID'd. It has a greasy and subadamantine lustre. It can scratch a U.S. Quarter Dollar and some types ...
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1answer
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would someone be so kind as to identify this rock i found? [closed]

What is this rock I found, it's got little glittering things on it. I found this in Sussex county New Jersey, it was used to line my driveway with a bunch of other rocks, other than that I don't know ...
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Is it ever possible for an continental plate to subduct under an oceanic plate?

It is well known that oceanic plates subduct under continental plates. This may be attributed to the plate's age and density, plus the water on top of it. So I was wondering if it is ever possible for ...
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how best to preserve the color of my amethyst geode?

Will bright indirect light cause an amethyst crystal to fade? How about an overhead LED light? How is best to preserve the color of my amethyst geode? Thank you!
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1answer
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Where to start searching to find more radioactive minerals?

I'm pretty new to all this... I've recently purchased a Geiger counter, and am hoping to locate rocks like pitchblende and other radioactive minerals for my collection. I'm based in the North West ...
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Formation of foliation in predominantly dolomitic marble

How can foliation form in a predominantly dolomitic marble which includes pervasive chert in the form of beds and nodules. The marble appears extremely pure which would lead me to believe there is a ...
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1answer
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Please explain how this rock could be shaped like this [closed]

i found this amongst some river rock. Please explain why or what happened to it.
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Is this Jadeite Jade? [closed]

Bought this online, shipped from India, I was told that it is Jadeite Jade and not Aventurine, it comes from China and India, I tumbled one piece. The piece on the left is 2 3/4 inches. A beautiful ...
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1answer
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Using acoustics to measure the composition, density, and hardness of layers

I am an engineering student at Alfred University and some fellow classmates and I are doing a competition, but one of the tasks we need to complete is autonomously measuring the composition, density, ...
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1answer
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Asking about type Fossil [closed]

Can any one help me to identify this type of fossil ? Its dolomite limestone
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Identification of a rock. White marble? [closed]

Could you please help me identify the rock found commonly near many of the ancient Greek foundations and rubbles? This one was at the base of Poseidon's temple. White in colour with a smooth texture ...
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1answer
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What are these Pebbles

Found these Pebbles at a lake edge where a Serpentinite belt runs through, there are lots of serpentine pebbles along this lake in Co. Sligo Ireland. The larger pebble is 1 5/8'' a Yellowish white ...
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2answers
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I found this strange spherical stone in Gillette Wyoming. I have no idea what it is. Please help.

These are recent pictures of it. It’s heavy, I see small minerals that catch the light in it, very bumpy, spherical, doesn’t seem to be magnetic, I was falling down a deep trench and kicked it up at ...
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1answer
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What kind of purple stone is this?

I found this stone and I do not know what type of stone is this?
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2answers
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Is this Mutton Fat Jade?

Found this near the Shannon River close to Carrick on Shannon Irelandenter image description here Could this be Mutton Fat Nephrite Jade? Thank you
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1answer
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What is this rock found in the Illinois Valley of Southern Oregon?

I found this odd shaped rock along a rocky river bed (dry) near the Illinois river in Cave Junction, Oregon. It is shaped like a Club and is super heavy. It has a distinguishable ring around the ...
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1answer
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Please identify- no origin known but given to me by a geologist

A very dear man who love his job as a geologist gave this to me. He’s been all over the country so I have no idea where he may have picked it up
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1answer
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Please help identify

I have had this rock in my yard for close to 10 years. It was left behind by the previous tenant. Can you help identify it? It has layers, a mixture of soft and hard, and is tan to white in color. ...
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1answer
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heavy, brown, rock with crystals, please help identify

please help identify this rock. it is heavier than most. dark brown color. picture is shown with streak test. found in Philadelphia pa. at home demolition site. crystals seem to be different type and ...
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Rock identification - origin unknown

I'm trying to identify this rock. It's fairly fine-grained and has a green tint. It's fairly heavy for its size, I cannot scratch it with a figernail but I can make a scratch with a knife. The rock is ...
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What types of stone are these rocks I found in Scotland

Please could someone tell me what type of stone this is I came across it while walking my dog. I'm in the highlands of Scotland!
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python generate 3d unstructured grid

I would like to create a 3d unstructured grid based on data points with xyz and property. Can Python do this and what tools? My question is quite generic but i can provide more details: the data has ...
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What gold colored rocks are these?

I found these golden coloured rocks while digging on a construction site in Surrey. Can someone help me identify what they actually are?
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1answer
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Rocks sparking under water

I have searched for an answer to this question for years, to verify if it was true. A man that lived on a river in the rugged part of the northern Washington Cascades told me an interesting story. He ...
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1answer
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Historically, how did the total amount of salt / NaCl on Earth develop?

After reading this question about the origin of NaCl on Earth, I'm wondering: How did the amount of NaCl develop historically? Is it a more or less linear growth until today? Was it such a linear ...
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How do I generate a Moho depth model from seismic refraction data?

There are several permanent seismograph stations in Eastern Canada that have been recording arrival times for over 25 years. Using refracted Pn arrival times from natural earthquakes I would like to ...
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2answers
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How do the different densities of the oceanic and continental crust affect earth's outer shape?

I am currently reading a textbook and I am slightly confused at a paragraph that deals with some general facts about earth's outer shape. It mentions that the density of the continental crust is ...
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1answer
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Is astrochronology a proper method?

Wikipedia's definition of astrochronology is: "Astrochronology is the dating of sedimentary units by calibration with astronomically tuned timescales, such as Milankovic cycles,1[2] or even ...
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2answers
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What caused this waterfall to have rounded formations?

This is at Bua Tong Waterfalls in Chiang Mai, Thailand. Tried to find scientific information about this waterfall, but google turns up only travellers' vague guesses, suggesting calcium carbonate ...
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What are the name of these stones?

There are some kind of stone, I collected them and I want to be sure of their identification.
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1answer
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Please identify this pink transparent stone?

Pink transparent stone it maybe obsidian but my research indicates pink colour is very unusual for obsidian It’s translucent, all pink, slightly refractive you can read letters through when stone is ...
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Peculiar Piece of Petrified wood? Or just another piece

Multiple years ago I found a chunk of petrified wood in my grandmothers yard in Northern Utah, what is unique about it is you can see the transition from rock to wood. But the wood feels like wood, ...
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Please help identify this! Rock? Glass? Crystal? It's big and very heavy [closed]

About 1.5 feet tall, 1 foot deep and 2 foot wide. Very heavy and very hard. I will get a better picture posted asap. You can read a newspaper thru it. Was left to me by my uncle years ago but never ...