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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Seeming correlation between time of day and earthquakes

I live in a generally geographically active area (Southern California, near the San Andreas fault, if that matters), that has had two relatively minor earthquakes that I have felt in the last week (in ...
8
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889 views

Math needed for Hydrology, specifically surface water hydrology

I wanted to know what math is needed for hydrology, in particular surface water hydrology. In my research online, of Master's programs (either in Hydrology or Environmental Science with a ...
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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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Time of concentration - Difference between large and small basins

I am looking for any academic reference (i.e. articles) regarding the time of concentration for large and small basins. E.g. I would expect that a large basin (area > 1,500 km^2) will flood (or reach ...
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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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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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What is the difference between eluvium and alluvium?

I was reading about kimberlite on Wikipedia and it mentioned eluvium. I've heard of alluvium, alluvial fans, alluvial deposits, etc. However, when I looked up eluvium, it sounded exactly like alluvium....
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Can anyone help me identify these rocks please?

I apologize for any errors in my pictures or writing. My first post. [
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1answer
66 views

I need help to identify this rock

I would like help to identify this Stone. I found this stone in my back yard. I would just like to know if it is worth anything or if I'm just going to add it to the driveway.
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Subrelluric forces in a volcanic eruption

I am listening to a song about volcanoes. It is called "Pyroclastic Annihilation" performed by a brutal deth/thrash metal band called "Demolition Hammer". It is from their album "Epidemic of Violence" ...
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2answers
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What is this? A sinkhole?

Lat., long.38.47491, 43.48882, in the vicinity of Van in Turkey I saw this when hiking. I want to know what it is and what are the dangers it poses. Lots of people hike that area in spring and summer,...
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1answer
79 views

Can anyone help me identify this rock?

This is probably just something really common and boring to most people, but I was intrigued so I thought I might as well ask now I can. When I was in Portugal (I don’t know specifically where we were)...
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Rock ID: Dark, Hard, Midland Valley Scotland

Found this in a river. The dark part is the rock still drying out. I think the smoothness is the weathering from the river. The rock is heavy and a little bit rough on the underside among the ...
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Whats this stone?

Found it couple days ago and it amazes me how smooth the surface is but cant identify it please help me. Found it in north germany near a lake on a trip there.
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Can you help me identify my rock?

I found this rock in my yard. Can someone please identify it for me? I’m not sure if you can see the blue hue on the rock in the picture! (https://i.stack.imgur.com/cuklH.jpg)
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Is this very old glass or a type of crystal?

I found these in Spain buried within a very old rocky sea bed along with many fossils, would this just be peices of damaged old glass or is it some form of crystal/rock? Thank you in advance
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1answer
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Please help me identify the inside of this stone

please could you help me identify this stone I found on the beach, it almost looks like it has tiny eggs inside but they definitely aren’t as they are solid and aren’t removable Thank you in advance
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1answer
52 views

I need help to identify this Stone [closed]

I would like help to identify this Stone. I have found a large amount of these stones in my yard. I would just like to know if they are worth anything or if I'm just going to have a pretty driveway ...
5
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1answer
132 views

What is meant by Massif?

In India, Panchchuli, Kun Nun and Shilong only these mountain are claimed to be massif. Why other mountain formations are not termed as massif...? What are the characteristics of massif..? Anybody ...
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What kind of rock is this? It was inside a bigger rock

I found this when I was really little, and I'm 18 now. It was inside a bigger rock; the three pieces fit together to make one piece. The biggest piece seems to have some kind of fossil on it. I've ...
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If the earth were completely smooth and covered in water, what would occur with ocean waves?

Related to this post: If the Earth were a smooth spheroid, how deep would the ocean be?
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1answer
124 views

Mineral identification; black & metallic

During a recent trip to the Portuguese island of Madeira, I found a couple of interesting rocks on a beach. Both the rocks pictured in this question contain the same black mineral. I first guessed ...
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1answer
52 views

Can someone help me identify this crystal

So the actual rock looks black but I put it up to the light n I see green n black.... can you help me figure out what it is ? my grandfather gave it to me years ago n I’d like to find out more about ...
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392 views

Why do some earthquakes and volcanoes occur within plates?

I know that volcanoes and earthquakes occur on plate margins. But, do some of them also occur within plates?
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Is it possible to create clouds by pumping water into volcanoes?

Suddenly, there is this idea in my mind that if an important effect of global warming is rainfall reduction and drought, is it possible to use volcanoes as water vaporizers (regardless of costs)?
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Why are the mountains predominately grey or dark brown?

Observing many photos of mountains one can assume that most of the mountains are grey or brown. See also the mountain article at Wikipedia. There are however several ways a mountain can form, which ...
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1answer
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What is this heavy rock having gold-olive colour and tiny gold coloured crystals?

The rock is very heavy, about 1.2 kg and 5 inches (~ 13 cm) long, gold–olive colour. The back has tiny gold coloured crystals and the front has bigger ones as seen in the picture. I don't really know ...
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What can one come to know about a mineral just by knowing name

I have been busy learning the components of various minerals for upcoming test....is there any way to predict the components or properties of a mineral just by knowing it's name? Eg: albite,augite, ...
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I found this huge rock crystal by the river have no idea what it is?

![crystal rock yelowish to red yellow to orange has 3 layers of crystal )
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Is this a fossil

It this a stromatolite fossil? If it is, it’s probabaly at least 1 billion years old
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What kind of gem is this

I had got this as a kid and I am wondering if it is worth anything.
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1answer
100 views

Does crustal thickness have anything to do with how life existed and sustained on Earth? [closed]

The original question that was put on hold "If the crust were the thickest layer of Earth, what effect would its thickness have on organisms?" was actually one of those 'counterfactual question' ...
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How big does something have to be to cause an atmospheric event upon entry to the Earth's atmosphere?

The question is about a foreign object, ranging from an asteroid to a spaceship. How large does it have to be in order for its presence to start messing with the weather patterns, causing the like of ...
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1answer
113 views

How does this melted-wax erosion pattern form in sandstone?

How does this kind of erosion pattern that looks like melting wax form in sandstone? Can you describe the kinds of processes and kinds of rocks that are needed for this? I've seen it in Nevada, but ...
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1answer
487 views

What kind of rock is this gray and brown weathered cylinder-shaped rock I found near a New York lake?

I found this rock on the beach of a freshwater lake in the Finger Lakes region of New York state and am interested in knowing more about it. It is about 2" tall and 2" wide at widest point. Weighs 14....
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1answer
104 views

What on Earth in can repel a magnet? [closed]

The iron in blood is naturally repelled by a solid magnet the opposite of iron outside of blood by a magnetic field and I wander... Are there any elements that are repelled by a solid magnet? https://...
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Identifying rocks, minerals

I am sorry to bother you.. before passing away, my grandfather gave me a special box that contained all types of beautiful, colorful rocks and minerals. I am having a hard time identifying them! Could ...
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1answer
397 views

Is this platinum ore? Mohakite? Found in Michigan

This was found in a river in southeastern Michigan. It is very light (about 14 grams) and not magnetic.
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ALOS Palsar SLC data products for geological mapping

I have some ALOS palsar SLC data products which are downloaded from ESA database and they are processed with ESA ALOS-PALSAR IPF processor which is different from JAXA. Formerly it was not possible to ...
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2answers
256 views

Is an underground mine collapse or a tunnel collapse called a sinkhole?

Imagine there's an underground man made structure e.g. a tunnel or an underground train station that collapses creating a depression in the surface. Would that technically be called a sinkhole? What ...
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1answer
138 views

Are these obsidian snowflakes?

I'm not sure if these are obsidian snowflakes: I found it near a river, hardness is 4 to 5, it has a wax lustre when pre-polished. The 'flakes' in the matrix are raised and gray. Pre-polished side ...
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206 views

Dark heavy rock

I found this dark heavy rock near Wombeyan Caves NSW. Australia. It is 9 by 6 cm and weighs 353g; it is not magnetic and was found in a dried up riverbed.
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1answer
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What separates the Karakoram Range, the Hindu Kush, and the Himalayan Range?

In Google Maps, I don't see any boundary between the Karakoram (a.k.a. Karakorum) Range, the Hindu Kush, and the Himalayan Range. What separates these ranges?
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Can someone identify this geode found in upstate NY

Can some identify this geode? It was found in upstate New York in a flat sandy plain 1/4 away from the Hudson River. The geode is approximately 3" long, brown exterior, 1/4" "shell" gray , and 1 1/2" ...
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1answer
151 views

Is this deep green calcite, green gneiss stone?

The site where it is found is characterized by schist, quartz and gneis, but also other species of rock. This is a scissors 2 cm semi transparent, vitreous luster, hard scale 6.5 - 7 ... I will post ...
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1answer
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What kind of stone is this?

Years ago, I bought from a flea market two strange looking stones, that the owner said he had found under the sand of a dune in the desert (I don’t remember which). Maybe it’s true, maybe not, but I ...
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Geology - Rock Identification help please. Melted metal looking rocks in the middle of nowhere

I know nothing about rocks. But I found this and a bunch more that are similar hiking up a river in the jungle of Laos, in SE Asia. If anyone could help me ID it hat would be awesome because we are ...
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Zeolites, odor control, and the witchcraft of sunlight

Various companies offer "volcanic crystals" or "volcanic rock" available in small mesh bags for odor control. The best description I have found is that these are made up largely of Zeolites. All of ...
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1answer
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How does the synthesis of Kaolinite (and it's by products) influence porosity in granodiorite?

I started studying the effects of weathering on granodiorite (see previous posts) and plan on referencing the link between the chemical weathering of feldspar plagioclase leading to kaolinization, a ...
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In an Earth-like planet with no history of carbon-based life forms, would there be limestone?

The extent of my understanding of limestone is about what Wikipedia says at the very top of the page: Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such ...