Questions tagged [crust]
The crust tag has no usage guidance.
49
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Why should there not be water deep (e.g. below 6 kms) in the Earth's crust?
In 1970, the USSR began drilling at the Kola Super-deep Borehole. The target depth was 15,000 meters;
The stated areas of study were the deep structure of the Baltic Shield, seismic discontinuities ...
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1answer
63 views
Term for the Process of the Early Earth's Crust's Changing Mineral Composition
In the book, Story of Earth-The First 4.5 Billion Years, From Stardust to Living Planet, by Robert Hazen, Chapter 3: He discusses the changing mineral composition of the early Earth's crust from ...
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25 views
Where can I find an anisotropic PREM-like model for Earth's interior?
So, I just discovered PREM (the Preliminary reference Earth model) which models the density distribution of matter inside the Earth to any depth.
The PREM is very convenient but since it only depends ...
6
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1answer
66 views
Why is calcium so much more abundant in/on Earth's crust (and oceans) than it is elsewhere? (relatively speaking…)
Inside the entire Earth as a whole, and throughout our Solar System and galaxy, etc., magnesium is at least 14 times (or more) as common as calcium, atom-per-atom.
But, on Earth's crust and oceans, ...
3
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2answers
111 views
What's the official reason why it became so hot in the Kola borehole?
The Kola drill went 'only' a third the way to the mantle, so its deepest point was still closer to the surface than to the mantle. Why did the drillers experience 180 deg Celsius when so deep, where ...
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0answers
46 views
Crustal age global map
I've been searching for a map depicting the age of each part of the crust for a long time. I'm not a geologist but I'm a physicist so I would like to know about the most up-to-date and accurate ...
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1answer
84 views
Why does the Earth's crust have more aluminum than magnesium while the Sun has more magnesium than aluminum?
Magnesium represents 0.07 % of the composition of the Sun's photosphere while aluminum represents 0.006 %. Therefore, there is much more magnesium than aluminum in the Sun's photosphere.
But the same ...
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1answer
99 views
What was the Earth's continent's positions 10000 years ago, or 11700 years ago, AKA when the late Pleistocene epoch was coming to an end?
In many articles online, geologists and geographers have described and depicted the theorized locations of all our continental plates with great detail and illustration, providing pictures, time-lapse ...
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1answer
88 views
Are the precious metals (silver, gold, platinum) present everywhere throughout the Earth's crust at least in the trace quantities?
Do some rocks, soils, sands or waters exist that contain fewer than one atom of gold per cubic meter or tonne of their mass?
3
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1answer
105 views
What would happend in distant future if we didn't extract fossil fuels
I'm sorry if that is stupid question. Geology is not my thing, but I'm curios about this.
Let's assume that mankind has never extracted fossil fuels (or existed in the first place) and for millions ...
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2answers
148 views
Do tectonic plates “float” over the mantle and “collide” like icebergs?
I'm always hearing about tectonic plates as large chunks of crust floating on the mantle just like boats. In timescales of millions of years they move and even collide.
But I'm starting to think this ...
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3answers
231 views
If the Sun disappeared, how long would it take for the Earth to freeze beyond excavatable depths?
If the Sun disappeared
How long would it take for the earth to freeze beyond excavatable
depths?
How long until it freezes to the core? (Is this different than without removing the Sun?)
Would we be ...
3
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2answers
1k views
If the Kola Superdeep Borehole were opened today, what would come out of it?
The BBC News article The Deepest Hole we have Ever dug says:
This is the Kola Superdeep Borehole, the deepest manmade hole on Earth and deepest artificial point on Earth. The 40,230ft-deep (12.2km) ...
2
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0answers
17 views
Why do ophiolites obduce upon Continental Crust?
Oceanic Crust is more dense than continental one. The margin between both types of materials can be passive or develop a subduction zone, where Oceanic Crust sinks under continental one.
I know there ...
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0answers
52 views
By how much did the Earth's diameter decrease due to cooling, if at all, since it was formed?
The answer to How long until Earth's core solidifies? question cites an estimation that the Earth (as a planet, not the surface of it) has cooled down by about 250K since it was formed.
The question ...
3
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1answer
197 views
Why is there so much more silicon than carbon in the Earth's crust?
Some arguments I've seen about the viability of silicon-based life involve the relative abundance of silicon vs carbon. In the universe as a whole, there's a lot more carbon than silicon around. Yet, ...
3
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1answer
41 views
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
98 views
Is salt accumulating over time?
The rainfall leaches salts (Mg,Na,Ca,K,.., Cl) from weathering rocks, where those ions were freed from chemical bonds by sunlight, acidic water etc. The runoff eventually goes into the oceans, where ...
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2answers
530 views
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
498 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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1answer
166 views
Why did sinkholes emerge in Pakistan?
Here is a video.
Why did the sinkhole emerge in Pakistan? Is this because of the heavy exploitation of groundwater?
What could be the solution?
Reference
In pictures: Chaos as rain continues to ...
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2answers
268 views
What if we detonated the entire worlds nuclear supply in the center of the earth? [closed]
What would the effects of detonating every single nuclear bomb currently in existence at once in the center of the earth? Would the earth simply explode into bits? Would the heat have some sort of ...
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4answers
9k views
What is the deepest we have ever gone into the Earth?
I remember Journey to the Center of Earth and wonder: What is the deepest in the Earth surface or below sea level we have traveled either by foot, sub, drill or camera?
5
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2answers
241 views
Why is lithium so unevenly distributed?
According to the US Geological Survey, nearly all of the world's lithium reserves are in Chile/Argentina, China, and Australia. Why is this? Lithium seems to be mostly harvested from brine pools, so ...
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1answer
380 views
Why does Earth have two kinds of crusts?
Why does Earth have two clearly differentiated kinds of crusts, namely continental and oceanic? How did they differentiate initially and why don't they get mixed up over time?
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1answer
549 views
Can a shock wave travel around the Earth's curvature?
Can an explosion be felt in the ground on the opposite side of the Earth like from an asteroid? Would planes in the air on that side of the Earth be able to survive?
Does the shock waive follow the ...
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3answers
5k views
Do fossil fuels insulate the crust from the Earth's interior?
I was doing a project for my English class, and I came upon the article Energy conservation in the earth's crust and climate change. I can't view the full text of the article, but the abstract piqued ...
4
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0answers
78 views
On which software can I simulate landmass collisions?
Such as in 3D simulations of vehicule crashes but this time with huge rocks or bodies of water (continental plates). I need to be able to set the properties of the material (density, size etc) and see ...
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0answers
85 views
Which places in Earth's crust have the highest concentrations of Iron?
Where would somebody find the highest concentrations of Iron on or near Earth's surface?
5
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1answer
347 views
Why does the loss of water from a felsic magma encourage crystallisation?
Felsic magmas crystallise in the crust, unlike mafic magmas which tend to make it to the Earth's surface, for the following reasons:
They are more viscous than mafic magmas and therefore it is ...
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2answers
2k views
Why are most minerals so rare?
There are 4,660 known minerals, so why are most of them so rare?
Is it to do with the structure of minerals?
4
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1answer
726 views
What's up with the “jelly sandwich” analogy of the lithosphere, asthenosphere and mesosphere?
Here's what I know:
The lithosphere is hard because it is cold and low-pressure.
The asthenosphere is more deformable because of higher temperatures and pressures.
The mesosphere is below the ...
7
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2answers
449 views
What fraction of Earth's crustal material survives the supercontinent cycle?
I know that things are not as simple, but for the sake of argument I'll assume a supercontinent cycle of $\sim$400 Myr periodicity is active on Earth.
If that is the case, then my naive ...
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0answers
81 views
Are there any signs on the Earth's surface that indicate a shrinking iron core? [duplicate]
It appears that Mercury shows some cracks on its surface that were not caused by moving tectonic plates but by shrinking due to the inner metal core cooling.
The Earth is also cooling down, but are ...
8
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2answers
494 views
Composition of Martian Crust
Does the composition of the crust of Mars roughly correspond to that of the crust of Earth. That is, is the elemental abundance in decreasing order silicon, oxygen, aluminum, etc.?
3
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2answers
116 views
Need help understanding what an “isostatic model minimizing crustal deviatoric stress” means
Despite the background information coming from another body besides the Earth, the terms I would like to understand are historically geophysical in nature.
Background:
I just read today's news "...
3
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2answers
107 views
What would be the correct terminology for soft cover on crust?
Earths' crust is usually not exposed. Above-water portion is covered with soil, and Underwater portions are covered with various deposits or sediments. Oceans contain Pelagic sediments.(I don't know ...
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2answers
2k views
Which one is the correct concept of Continental Crust and Oceanic Crust?
I knew so far that, the classification of crust as SiAl-SiMa, vs. classification of crust as Continental-Oceanic; are completely different, as told in my school geography and university paleobiology ...
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0answers
62 views
Early Earth crust [closed]
My question is related to a former question about the Earth's early crust.
I would like to understand HOW the crust that seems to have been mafic during the Hadean, changed into the other more felsic ...
6
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1answer
630 views
The age of tectonic plates
There is information which says that East European Platform sticks out at the Baltic Sea and, therefore, we can see the ordovican layer in Estonia whereas ...
3
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1answer
272 views
Why do we see the limestone on top of Cambrian layer?
The official story says like Cambrian Ordovician transition was caused/accompanied by animals learned how to build the Ca-based skeletons. These skeletons and shells started to fall upon the sea bed ...
4
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1answer
241 views
Why is Great Oxidation Event associated with Iron oxidation but not Aluminum or Silicon?
Just to build up on my previous success with oxygen origin in the atmosphere, I want to expand the question as was advised in the answers. The official heresy, despite denied in the comments and ...
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1answer
1k views
Seismology: What causes an earthquake? [closed]
I am doing a research on earthquakes but I cannot fully understand what causes earthquakes.
"Caused by a sudden releases of energy by the Earth's crust, causing
seismic waves which causes the ...
5
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1answer
8k views
What is difference between divergent boundary and hot spot?
As I know, both divergent boundary and hot spot are formed by rise of magma of convention, but divergent boundary is a line and hot spot is a point, is there difference between 2 kinds of rising magma?...
2
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2answers
1k views
How is dense magma able to rise and punch through continental crust?
I am trying to understand how a dense basaltic lava is able to rise and punch through the continental crust, such as in mantle plumes or the Great East African Rift.
My understanding of plate ...
4
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1answer
627 views
Why is uranium only in the crust, really?
As I know, uranium is currently thought that it is mainly in the crust and not in the core or in the mantle. The reason for that it is a siderophile element which means it won't be solved in molten ...
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3answers
6k views
What do continents “lay” on?
It's a simple question.. What do continents "lay" on? Do they float on water? or are they huge bodies that "emerge" from the sea floor/bed? are they connected to the bottom of the oceans? Hope the ...
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2answers
698 views
What was the likely composition of Earth's early crust (how did crustal composition evolve)?
Was the first crust entirely mafic (oceanic) crust which was later distilled via volcanic arcs along subduction zones to make felsic rocks or did the earth start with bits of felsic crust?
Are the ...
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5answers
7k views
Why is continental crust less dense than oceanic?
Why is it that continental crust is less dense than oceanic, where in fact continental crust is thicker than oceanic crust?
