# All Questions

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### Can anyone tell me what this 'rock' is?

I found this in Topanga Canyon, California (LOS ANGELES). It's able to be scratched with a penny, but not my fingernail... so it's about a 2.75 i'm guessing, and the size of a baseball. I found this ...
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### Why is the upper atmosphere brighter than the lower atmosphere in some photos from space?

In most photos from space, the atmosphere gradually fades away from pretty bright blue to essentially black, as you move away from the Earth surface, such as can be seen in this photo of the Earth ...
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### Could unconformities be a tool for preparing a geological timescale?

Unconformities subdivide different strata of rock. However such a thing could only bear the temporary scenario of the depositional beds. Then how far it could be useful to build a whole geological ...
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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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### Need help identifying this rock

I need a little help identifying this rock. It was found somewhere in the Sahara Desert. It is very hard and leaves a beige streak on a steel file (might be the concretized dirt covering it). The ...
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### Endogenous Theories For the Origin of Earth's Water (Dry/Wet Accretion?)

I have really two questions: (1) what evidence is there in favour that the majority of Earth's water formed with the planet. (2) what evidence is there that the majority of water did not form with ...
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### Why is the atmospheric pressure in a tropical cyclone lowest in the eye, even though it contains sinking air?

The lowest atmospheric pressure in a tropical cyclone is generally located in the eye at the center of the cyclone; however, the air in the eye is descending, while the air in the surrounding portions ...
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### Are there resources for determining what percentage of the earth's surface is occupied by air conditioned spaces?

EDIT: My goal with this question was to better understand the impact of cooling systems on local urban environments, but its been pointed out I am asking the incorrect questions for the answer's Im ...
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### Rock/mineral identification - smooth black inside

It’s yellow and grey on the outside but smooth and black on the inside. Very roughly 2.27 g/ml Just curious, it almost like sea glass on the inside but it’s far too dense.
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### Hourly solar radiation estimates on a horizontal plane, preferably in R

I'm looking to estimate the temperature at the end of a river reach of a few miles in length based on known (measured) temperature at the start of the reach plus weather information: historical data ...
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### Would a nuclear explosion over one of the Earth’s magnetic poles momentarily disrupt/weaken the Earth’s magnetic field?

If say the Tsar Bomba had been detonated directly over one of the Earth’s magnetic poles at ground level, would the nuclear electromagnetic pulse generated from that blast have had any momentary ...
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### 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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### what is this round black rock contained in sandstone [on hold]

Wondering what this rock is, found in the spring mountains near las vegas nevada. It is a hard smooth feeling black rock which appears to be surrounded with sandstone, the black rock goes all the way ...
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### Lake outflow forming a “reverse delta”?

While rivers often form a delta when they flow into a lake, the outflow of a lake is usually a single stream. Are there lakes where the water flows off in multiple channels that merge into a single ...
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### Can someone help identify this stone please [on hold]

I have numerous rocks that are in need of identification, and hoping someone knowledgeable can help! In rough form it’s a metallic blad almost waxy, and some show red or green underneath
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### Is it possible to estimate the size of a meteorite from its remains?

I live near this ophiolite (Sasso di San Zanobi, Firenzuola) and they used to say it is a meteorite. There is no evidence of a crater but let's pretend it is the remain of a meteorite: how big would ...
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### Help me figure out what this purple rock is

I found this in the ground at a job site in blue springs mo . Its purple with darker purple lines through it like growth marks on a tree. It is about the size of a large loaf of bread 7 inches across ...
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### Geological work of rivers and glaciers [on hold]

I'm new to new this platform of Earth science, I'm studying for an entrance exam in geology in my country. I wish to learn through this stack exchange also. Thanks... Question: what would be ...
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### 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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### Hi, I'm hoping to identify this rock.

Would anyone be able to identify this rock?
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### 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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### Geological evidence about climate change: has there ever been a period with a rate of climate change as great as it is today?

Most statistics about climate change are based on climate data over the last 150 year (as long as records have been kept). This seems irrelevant in terms of the geological time scale of temperature ...
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### Could further oil drilling remove an insulation layer of the Earth cores heat? [duplicate]

Putting aside burning fossil fuels, what are the consequences of another 100 years of drilling deeper and deeper to extract oil reserves globally? Would this significant extraction remove an ...
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### Why are pole reversals not more detrimental to life?

This question is linked to the following question, and has two parts. Mars interdicts approximately 40% of the radiation (per square meter) of the sun that Earth does. It has been claimed that Mars ...
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### Another mineral inside this Rainbow moonstone?

I got this rainbow moonstone from Jaipur, India. The front and back are polished, has black tourmaline around it’s edges, and is 25x28mm. I didn’t notice it when I bought it but It seems to have ...
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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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### Help with identification

I'd appreciate it if someone knows something about this rocks. This is new for me so I'm like a child :) but they are so beautiful. From Bosnia, place was cemetery in WW II. Thanks
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### Can anyone help me figure out what kind of rock this is?

I was cleaning out my basement and I found this wrapped in a cloth inside a tin case. Does this rock hold value? What is the geological history of it? I'd really appreciate insight on this.
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### Agricultural self sufficiency after yellowstone eruption?

Given a 440 acre farm running roughly 200 acres of Crops and 40-50 head of cattle,in the secondary ash zone within the lake of the ozarks reigon of Missouri, how viable would survival be relying on ...
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### How to Interpreted SEM-EDX result? [closed]

I am new for SEM-EDX but I want to learn. In the EDX data result, there are Wt % and at % from every element (for Example if : Wt % C 14.16, O 51.22, Al 2.22, Si 30.64, Fe 1.75 and At% C 21.11, O 57....
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### What type of lightweight “stone” is this?

This is lightweight compared to almost any other stone I've held. I found it in Michigan, in sandy soil about 24" deep. Broken side:
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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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### How we can find hot spring genesis time?

Is there any way we can calculate the time when a particular hot spring come into existence? Also I wanted to know what is average time period for a active hot spring in general, whether it can flow ...
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### Where on Earth does the atmosphere have the most $O_2$ concentration?

Is there a map that shows the average oxygen concentration in the atmosphere? Seems to me that it would be where the most plants are but I wonder if population and industry make a difference in oxygen ...
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### Could you help me identify these rocks please

Found these whilst walking around Warwickshire please could you help.thanks
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### Why is there no desert in Southeast China?

Arabia, Sahara and Southeast China and India all are on the tropic of Cancer yet Southeast China and India are not deserts. I know that India is not a desert because of monsoon wind which causes heavy ...
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### How would Earth map look like if all ice melts?

Is there somewhere a map which indicates which areas and cities become sea?
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### Water vapor content versus specific humidity

I am wondering the difference between water vapor content and specific humidity to determine the moisture availability in the atmosphere. Which one is more acceptable variable to determine the ...
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### Sun and moon anomally

Below is a photo that my son took in Scotland showing the sun and moon at the same time. I immediately noticed this anomaly that the light illuminating the moon could not possibly come from the sun. I ...
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### Why do rivers sometimes travel down the opposite side of the mountains from where the rain happens?

My teacher explained that when wind coming from the ocean gets blocked by a mountain it makes rain on one side of the mountain, like in the image below. This rain leads to the creation of rivers. (...
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### Why does the hardness of Cu & Al vary?

I know the a mineral's hardness is determined by its bond strength and crystal lattice.I know that both Cu and Al have FCC structure but how do we predict its difference in harndness with close ...
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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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### I believe we got this rock in the mountains of Creede Colorado

Solid, has some weight to it, looks like it possibly has some purple amethyst on the opposite side, but mostly consists of this silver: Can anyone identify it as silver?
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### What is the oldest fossil on Earth?

What is the oldest fossil ever found on Earth? Where and when was it found? What was the oldest fossil with a brain with 2 hemispheres ever found?
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### Identify Crystal [closed]

These are pictures of petrified wood just wondering if you could tell me what the round fools Gold looking crystals are I know the yellow crystles are Amber and was told the round Fool's Gold looking ...
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### What is the angle between earth's axis of rotation and equator? Are they perpendicular or at 66 1/2 Degrees?

By rotational axis I mean axial tilt or Axial obliquity or 66 1/2 degrees tilt of earth to its orbital.
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### What is the name of the rock and the minerals it contains?

This rock was given to me for mineral identification during my Economic Geology Class.Now , I have managed to spot some of the minerals here , but I am not too confident with my answers. The lab ...
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### Is this an Agate? What kind? Or what kind of rock is it if not Agate?

It think is an Agate but not sure what kind of it is. As best as I can tell under the orange its really pretty. It is 21 lb. I found it at a rest stop out side of Yakima, WA, USA. But it does not ...