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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How far deep in the mantle has any rock ever been brought to the surface? Have scientists found anything they believe originated in the outer core?
I wonder if this is even possible to know....
Do geophysicists and geologists have even a 'theoretical' idea about how deep Earth's churning of its layers goes?
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How is the apparent volume affected by particle packing?
This is from paper "The packing of particles" by A.E.R Westman and H.R. Hugill.
Here they give result as, "it is evident that if the diameter ratio is
unity, ie., the coarse and fine ...
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How accurate is the law of superposition?
Recently I started being more interested in the rational details of the sciences (... being often challenged about them by a creationist friend) and one of the creationist 'theories' I've encountered ...
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Do subducted continents rise up again through ridges?
Layman here, sorry if this is a stupid question. I have a geology friend who recently told me that plate tectonics is like how warm milk cools on top to form thin solid layers. The convection cells in ...
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Are These Leaf Fossils Found Near a Texas Lake Shore?
I recently came across some intriguing specimens near a lake shore in Texas and am seeking your expertise to help identify them. The objects have a few characteristics that lead me to believe they ...
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Does the collision of India influence the geology and geography of some of the other mountains of Asia, or just the Himalayas and Tibet?
This here is a nice and lovely map of Asia. Note that the teardrop-shaped Tibetan Plateau dominates the map, and we have India to thank. For the last 50 million years, it has been pushing upwards, ...
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What forces plays the role in order to subduct the denser tectonic plate under the lighter plate?
I am a 10th grade student and I don't know much about geology but I'm learning about subduction online. It's always mentioned that the denser plate gets subducted under the lesser denser plate. I want ...
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Can a braided stream create thick relatively continuous siltstone beds?
I am attempting to interpret an outcrop I went to. I suggested it was created by a braided stream. The one thing I cannot explain are prominent alternating siltstone and sandstone beds. There are ...
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What is the geologic origin of the Bauxite deposit in Bauxite, Arkansas, and could there be more?
Bauxite is an mineral of Aluminum. Despite a general mineral wealth, the USA does not have any major Bauxite deposits, except for one in Arkansas. The mining town was named Bauxite, Arkansas.
The ...
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How fast can water erode stone?
Is there a way to know, how fast can water erode stone? I mean, if I just put a single stone and drip water on it 24/7, how soon will erosion become noticable?
I've seen a video about "15,25 and ...
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Does this support Hapgood's Earth Crust Displacement Theory?
I'm no Geologist by any standard but I'm quite intrigued by what goes on below our feet.
I came across this article that states there's a new or (confirmed) partially melted layer in the athenosphere (...
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What is 'dissection rate'?
I am looking for a definition of this term for wikipedia, with a reference.
It's mentioned on Franz Josef Land where it's indicated that the units are km-2/km. I'm curious about how this would be ...
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Why are most islands in the Caspian Sea elongated and some of them even have tails?
I was seeing the Caspian Sea from Google Maps satellite mode and I found most islands are elongated in shape (the biggest of them Ogurja ada or Ogurchinsky island).
Also there are islands that have ...
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Why is basalt denser than granite?
If lava is nothing but magma breaking through the earth's surface, then why is basalt more dense than granite?
I understand that something happens during the cooling process, but cannot find any ...
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Where can I get Carbon Capture Storage data?
I need CCS data for Carbon Injection monitoring for a seismic hazard study. Is there any open source data that related Carbon Injection monitoring for example seismic, wells, 1/2/3/4D seismic and etc.
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Is there geological evidence that the moon once collided with the Earth?
I've seen models in astronomy that show how the Earth-Moon system must have come together after a collision. However, I have not heard whether there is any actual physical evidence on Earth that ...
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Did the 1990 Manjil-Rudbar earthquake postpone a massive earthquake in Tehran?
In this site (published on 6 November 2001) I found the following information:
Historical data suggest there is a major earthquake in Tehran every 158 years and the last one there was in 1830.
The ...
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How the small stones in this photo are created?
I need some help with my grandson's school homework: can someone describe what's the phenomena behind the creation of these small stones at the plateau´s foot? why & how are they created?
No big ...
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How can smartphones help geologists in the field?
Smartphones have incorporated many sensors and some of them can be helpful for a geologist in the field:
They have GPS, so it is possible to register your route in a Google Maps map. I find this may ...
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How important or necessary are assumptions when it comes to radiometric dating?
So when I say radiometric dating, I'm specifically referring to U-Pb, Ar-K and Rb-SR rather than C14 as I think these are more accurate when it comes to corroborating an older earth. I've heard people ...
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MS in Geosciences With Concentration in Environmental Geosciences Degree Outlook
I am considering a MS in Geoscience but am curious with the naming conventions associated within the fields of geology. Is Geoscience similar, or interchangeable with geology? Yes, I would be new to ...
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Is the Theia impact partly responsible for the distribution of mantle plumes?
I was looking at a map of the distribution of mantle plumes, and was wondering if they could be residual material that was either brought here or affected by the Theia impact.
It seems to me that this ...
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Mud cracks formation
Are mud cracks formed during rock formation or after the rock is completely formed?
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Was there once a glacier over Starcke national park in Queensland Australia?
I was randomly exploring Google Earth when I came across some sort of rock formation in northern Australia. The location of the rock formation with respect to Australia is shown below. It is in or ...
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How was the Boesmansgat Cave in South Africa formed?
I found nearly nothing about this sinkhole online. Apparently the cave has water dating back thousands of years.
From where did this water come from. Is it just rain? And how dirty is the water now?
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Are there minerals which are not been found on earth but which are still possible to exist?
On Earth we find many kind of minerals, a lot of them are silicates. How much different kind of minerals would there be on Earth?
But are there Fe minerals found in meteorites which do no occur on ...
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Coarse grains in a sample of Rhyolite suggest that it formed by
Coarse grains in a sample of Rhyolite suggest that it formed by ……
A-rapid cooling of molten rock materials at the Earth’s surface.
B-slow cooling of molten rock materials at the Earth’s surface.
C-...
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How can we know the past height of mountains?
In Feynman Lectures on Physics Volume I, Feynman talks about the relation between Physics and Geology. He says “Mountains are no lower today, on the average, than they were in the past”.
Through what ...
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When was the thickness of the Earth's crust calculated?
When was the average thickness of the Earth's crust first calculated or estimated? What did scientists know about the thickness of the Earth's crust before the 20th century? In what interval(s) fell ...
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Suspended sediment yield
I am finding it difficult to understand the factors that affect the suspended sediment yield in an area. I was thinking of the Rouse number and how it is affected by the particle diameter, slope and ...
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Understanding the Facies and its Interpretation in Terms of Processes and Possible Depositional Environments
Fellow sedimentologists and geoscientists! I'm seeking your expertise in understanding a particular facies and its implications in terms of sedimentary processes and potential depositional ...
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Map of earth subsurface temperature
I see similar flavours of this question have been asked a few times, but I still don't see a satisfying answer. I am looking for data (maps) of the earth subsurface temperature at a depth sufficient ...
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Why is the inner core about 85% iron and the rest (mostly) nickel, while the outer is roughly 80%/20%, if nickel is denser than iron?
The question is basically the title. I really cannot think of a good reason. Is it a mystery to geologists?
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How'd this hole get here?
Hiking in a field of boulders along a river canyon in Alabama United states. Sandstone boulders are 20'-30' (6 to 9 meters) tall. There are perfectly round holes near the top. I'm wondering what ...
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Is there a theoretical maximum size limit for a rock?
There are many types of rocks: igneous rocks, sedimentary rocks, and metamorphic rocks. Some rocks are simply huge. Some of them are tiny. Is there a theoretical upper limit on the size of a rock, and ...
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Will a Mohs hardness scratch pen need to be replaced or resharpened?
I am considering buying a set of Mohs hardness scratch pens (aka hardness picks). As a hobbyist the price is quite high, starting at 300 USD and upwards for a complete set. I can accept this price if ...
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What kind of chromium is in common limestone?
I was thinking of crushing up some common limestone for microminerals because the water where I live has nearly zero calcium content. So I read about the trace elements of limestone and It says ...
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What are these geological horizontal lines formed on this mountain called and why they are formed?
This images are of Mt. Kailash, Himalaya.
Front face of Mount:
Back face of Mount:
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What is the white coating "patina" we often see on deposited chalcedony/agate?
Me and some of my friends were wondering what exactly is the white coating we can see on chalcedony that has been deposited by a river during quartenary (and so the original material is damaged and ...
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Google Earth type, online plate-techtonics demonstration over time
I once found an site on the internet that displayed the continents in a Google Earth type setting where you could spin, zoom and navigate around the Earth but in different geological time periods. You ...
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Hydrogeology Aquifer Question - Estimating Freshwater Availability
Bikini Atoll is at the northern end of the Ralik chain, and in a region that is somewhat drier. On average, the Atoll receives 1300 mm of rainfall each year, with the wettest season being from May ...
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Copper shale in the Harz Mountains (Germany)
I wanted to ask if you have any suitable literature on copper slate (especially about the genesis) in the Harz Mountains. I was generally interested in how this copper shale differs from other copper ...
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What is the pressure at the center of the Earth?
In the question Does gravity increase the closer to the core you get?, it was determined that gravity reduces to zero at the center of the Earth. That is logical.
However if pressure is proportional ...
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What explains the angled stripes of mineral visible on the side of some islands?
I was exploring some islands by boat recently and I came upon some pretty impressive rock formation. I'm interested in finding what mechanism produces those angle mineral strips. Some of them were a ...
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Why does calcium occur together with felsic rocks and magnesium with mafic rocks if calcium is denser than magnesium?
Felsic rocks contain a lot of sodium, potassium and calcium (and a great deal of aluminum), while mafic rocks consist of a lot of magnesium with iron....
Why is this?
Why is magnesium (z=12) in the ...
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At what depth does the ground stop getting cooler/hotter(summer/winter) and it starts to warm up?Where is the MAT depth or geothermal crossover?
Lookin into geothermal cooling, and want to learn more about how temperature behaves at different depths, not too deep like 100 meters or so, ignoring unusual stuff like geysers and things.
I want to ...
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Why are grain coatings an important mechanism for preserving porosity during burial in sandstone but not in carbonate?
I am writing a paper on the role of petroleum emplacement and grain coatings in preserving porosity during burial. I can find many sources discussing grain coatings stopping cementation in sandstone, ...
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What is the metal left behind by meteorites called?
I remember reading about a substance - I think it was a metal - left behind by meteorite impacts and nuclear explosions, but I can't remember the name. What is the name of the substance left behind by ...
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Speculative Plate Techtonics - Resolving intersecting subductions
I'm working through Artifaxian's (https://www.youtube.com/watch?v=AzD_WVsEIRM) series on using gPlates to make tectonic history. I've run into the place where I have two subduction ridges about to ...
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Is it possible that the rainbow sand dunes in Death Valley, California were formed by some massive mining in the ancient past? [closed]
I know there is a mainstream answer that thinks the rainbow sand dunes they be explained geologically... I just want to know if it's possible to form those colors and those dunes from mining? And if ...
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