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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If an asteroid strikes a glacier, does it make a print on the land below?

If an asteroid strikes a glacier, does it make a print on the land below? For example, a 10 km wide asteroid on a 2 km thick glacier, or a 2 km wide asteroid on a 2 km thick glacier.
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86 views

At what rate does Earth's atmosphere shed heat into space? [closed]

If we had a heat bank account (the atmosphere) + heat cash supply (ice) + heat debt (the oceans) could governments find a way to balance our heat economy that doesn't kill ...
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1answer
337 views

What structures form due to the melting of subducting plates? [closed]

What structures form from the melting of subducting plates? Plutons, Accretionary wedges, Deep sea trenches, Faults?
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1answer
261 views

Is altitude of everything decreasing due to sea level rise?

We know that sea level is rising, though some people say climate change is fake. Altitude is defined as the height of something measured from sea level. Since sea level is increasing, and the ...
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3answers
10k views

Would oceans regenerate if removed?

On Earth, there is enough Hydrogen and Oxygen to make 13,88 million km$^3$ of water (calculation below). However, oceans contain only a tenth of that. Clearly, most of the hydrogen must be stored in ...
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1answer
2k views

Newton's estimate of the age of the Earth

I was reading many articles about estimates of the age of the Earth throughout the ages. I was dumbfounded when I read that Newton, arguably one of the greatest scientists ever to have ‘calculated’ ...
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1answer
119 views

Is this Dragon Jasper?

Bought these rocks at a shop they were selling as Dragon Jasper,but when I density tested them they were 3.09 which I thought was a bit high for Jasper, and generally Dragon Jasper has Deep red veins, ...
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1answer
532 views

What is the basis for the Geologic Time Scale

The Geologic time scale was completed in the mid to late 1800s. What methods were used to date the various subdivisions?
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If the Earth were a smooth spheroid, how deep would the ocean be?

At the moment there are deep seas and high mountains. But imagine that the land elevation of the Earth is equal everywhere. How deep would the ocean be in that case?
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1answer
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Is this an agate? [closed]

So I have found these in a creek there are some that look like this and I have broke them open and they were full of crystals these seem to small and I have tried cracking then and they wont budge I ...
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1answer
64 views

Help identify my redbrown rock with crystal like formation on the inside

This rock is red/orange/brown in color. It is slightly clear/translucent when held up to light. Will not scratch with a knife. Has a crystal like structure on the inside.
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1answer
67 views

Identification of limestone type

These are images of a stone found and used extensively in the Jammu & Kashmir region between India and Pakistan. These are called devir or devri in the local parlance. Following is the ...
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Did low $\small\sf{CO_2}$ levels affected Permo-Triassic mass extinction?

After answering this question: How did plants adapt to $\small\sf{CO_2}$ levels past 400k years? Why won't they do it again? I know Permo-Triassic mass extinction is associated to a catastrophic ...
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1answer
137 views

Is this Jadeite Jade?

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
168 views

What is an isolated land area of one type of rock surrounded by land of a differing rock type called?

For example, if there were a large land area with exposed basalt, in the middle of which is a smaller isolated patch of Granite, what is that isolated patch called? I came across the single-word ...
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1answer
44 views

I found this rock on my property years ago and was curious what it was [closed]

What kind of rock is this? I found it on my property a long time ago and I can pinpoint exactly what. I was thinking red jasper maybe?
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1answer
695 views

What is the consensus among geologists about climate change being caused by humans?

I'm terribly frustrated with the way that climate change has been debated in Europe. I live in the Netherlands and members of one of the biggest parties here, the Party for Freedom (PVV), frequently ...
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3k views

What is this black, shiny, smooth, kind of heavy, metallic rock? [closed]

Its kind of heavy for it size, though not extreme - about two pounds. Looks like a chunk of metal, but not quite sure what it is.
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2answers
276 views

Can rocks have pressure signatures?

Since rocks can have magnetic signatures, as is the case with paleomagnetism, can they store past pressures also? For example, when researchers are trying to determine past ocean levels, they ...
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How was Nastapoka arc formed?

As wikipedia says, the Nastapoka arc is a geological feature located on the southeastern shore of Hudson Bay, Canada. (Other description with picture at the Royal Astronomical Society of Canada) No ...
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1answer
123 views

Could this rock be Basalt?

This rock is 2 3/8", weighs 71 grams has a density of 2.958,I tested the density a few times and its always 2.958, has a hardness of 6-7 almost clear streak test, I tested the streak again and I would ...
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1answer
125 views

What kind of lava tube feature is Cleopatra's Grave?

Cleopatra's Grave is a natural feature inside (warning: PDF) Catacombs Cave in Lava Beds National Monument near Modoc, California. Source: LookBeforeYouLive My apologies, as this image is somehow in ...
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4answers
5k views

Why is relative sea-level falling in Hudson Bay?

Why is the sea level in Hudson Bay decreasing so much? Hudson Bay is pretty far up north, much closer to glaciers. Would it make sense for it to recede at this level with sources of fresh water ...
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1answer
73 views

Sink holes in drainage area

I live in Florida (aka the land of sink holes). Due to the flat nature of my area, it is common place for housing developments (and any developments really) to dig large drainage areas to give water ...
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1answer
153 views

What is this green yellow heavy stone?

no known origin,its opaque its 2 1/4" leaves no streak, has a hardness of 6-6 1/2 I drilled it with a diamond plated bit,it is a very tough stone.It weighs 2ozs 56.6 grams.When I drilled it the powder ...
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1answer
305 views

How do you tell if smoky quartz has been irradiated?

I want to purchase a piece of smoky quartz crystal, but am not sure if it is irradiated. Is there a way to tell if it has been irradiated? Thank you.
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1answer
79 views

Can someone identify this mineral? [closed]

I found this in a stream in Medicine Bow-Routt National Forest, Wyoming. One side (2/3 length) has a pointy pyramid with four faces; other side (1/3 length) has four faces but with with an edge ...
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2answers
473 views

Why are South African mountains short and flat?

I drove through South Africa from Cape Town to Mozambique and noticed that almost all heights and mountains were no higher than approx 200-400 meters and had a flat top, just like the iconic Table ...
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1answer
528 views

What does strata mean here?

What does strata mean here ? These consolidated layered strata are known as stratified rocks. The strata vary in thickness and may be tilted or horizontal. The sediments consist of loose ...
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0answers
135 views

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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1answer
192 views

Please Help Identify My Rock

This rock is smooth, heavy and dark grey/black in color with white blotches which are different in shape and size and are also porous. It scratches by a knife and I found it in with many pails of ...
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2answers
3k views

Rock ID: smooth, black, durable rock from Lake Ontario

What is this black rock? I found it beneath the waters of Lake Ontario near the shoreline, it is a dark greyish-black with small flecks of mineral deposits on it that are visible in the light. The ...
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2answers
13k views

Why do crystals, like quartz and diamonds, form in different colors?

Some crystals, like quartz and diamonds, form in a variety of different colors. For example, quartz can be clear, 'foggy', pink, yellow, and even blue. What happens during the crystal's formation to ...
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0answers
28 views

How do people determine initial ratio of the parent nuclide and daughter product in radiometric dating?

I understand that we have zircon crystals that prevent entering or leaving of nuclide or lead after forming. But how cand we understand what was the initial ratio?
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1answer
350 views

What is this yellow stone

I found this yellow stone in a creek.It was easy to break by slamming it against another stone and has evenly spaced crystal clear grains.They are very clear that under the sun I thought that water ...
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2answers
1k views

What keeps water from sinking into earth?

I remember reading somewhere that there's evidence of water on Mars but it all sank into the Martian soil. So what prevents that happening on earth? Some people say it's because the crust is not ...
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1answer
116 views

Mineral identification - please help!

I'm currently writing an essay on a mosaic in the British Museum, and am unsure about which stone the frame is constructed from (pictured). I would be most grateful for help identifying it. Thanks! ...
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1answer
160 views

Is this a gold ore? I found it in a California creek next to a mountainside

I found this rock while hiking in a creek. It has some bits of white quartz, sheen and some brownish coloring. Does anyone know what it could be? Is there any possibility that it might be gold ore? ...
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3answers
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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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How are chenier ridges and strand plains formed at wave dominated coastlines?

In the attached image, we can see chenier ridges and strand plains. How are they formed and what is the involvement of rip and longshore currents in their formation?
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1answer
2k views

Earthquakes at plate boundaries

I was looking into tectonic plate boundaries and earthquakes with pictures like these One thing that is quite obvious is that some of the plate boundaries have very thin zones of earthquakes, ...
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2answers
3k views

Natural nuclear explosions

I'm aware of the Oklo reactor and other natural nuclear fission reactors, in which geological processes can lead to the formation of a sustained, self-regulating uranium fission reactor. Is it also ...
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272 views

Is this Black Serpentine?

I found this rock at a lake edge in Co. Sligo Ireland,its shiny black,leaves a black streak, weighs 320 grams displaces 125ml of water which gives it a density of 2.56 https://www.youtube.com/watch?v=...
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1answer
62 views

What type of rock is this? Help [closed]

Please help me identify this rock. I’ve found it in a cave.
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1answer
56 views

What is this translucent blue-green oblong crystal?

I think it might be aventurine of some sort, but I'm not sure. Hardness: It is harder than a steel nail file. The file leaves a track, but it rubs off, leaving no mark. I scraped it on the bottom ...
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1answer
48 views

What minerals are in this rock? [closed]

Can anyone venture a guess as to what minerals are in this rock? I’ve had it for years and have never been able to identify it. I believe I got it somewhere in Northern California but it was from a ...
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1answer
61 views

How do we detect floods?

How do we know that there was a flood at a certain place at a certain time. For example if there was a flood in place A 200 years ago. How could we detect it?
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1answer
146 views

What type of rock is this, Nephrite?

Its a very dark green opaque smooth rock, resists stainless knife blade 6.5-7 hardness, its 4x2cm, aprox 40 grams weight. I found this rock among cobble stones in County Roscommon Ireland.Its not ...
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0answers
23 views

The differences on the atmospheric transportation for various trace metal in atmosphere

I have known that the atmospheric lifetimes of chemical species were highly dependent on their physicochemical properties. For example, $SO_2$ might exist for 5-8 days, while $NO_2$ could only exist ...
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199 views

Making a local geological field trip an interesting and educational event for children?

I have no expertise in geology or earth science, but I would like to do a "field trip" with my home-schooled young children (under age 10) where I could teach them about geology from a hands-on ...