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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Waves in very thin layer

Elastic waves in the earth are described by the elastodynamic equations \begin{align} \rho \frac{\partial^2 u}{\partial t^2} &= (2 \mu + \lambda) \frac{\partial^2 u}{\partial x^2} + \mu \left( ...
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What is the difference between mobile & molten rock?

In the book Fundamentals of Geomorphology (Routledge Fundamentals of Physical Geography) by Richard John Huggett there is a sentence " Intruded rocks, which must be mobile but not necessarily molten,...
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How to make Martian soil [duplicate]

My son wants to replicate some experiments and try to grow plants in Martian soil for his A-level science project. I know NASA have managed to produce soil that mimics Martian soil, however I also ...
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How to make Martian soil

My son wants to replicate some experiments and try to grow plants in Martian soil for his A-level science project. I know NASA have managed to produce soil that mimics Martian soil, however I also ...
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Considering the thin piece of material on the surface of Mars in the image below, is there anything like it on Earth?

The above is a magnified part of the original image below captured by the Curiosity rover on Mars on sol 1729 (June 17, 2017). From the added information with that raw image it can be estimated that ...
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Puddingstone info sign for Trail Store

I run a Trail Store (sell hiking maps, swag, etc) in Mahwah, NJ, USA. I'm trying to feature a plant and rock every season. The first rock chosen is puddingstone. I created the short sign below, ...
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How likely is Earth to naturally reverse climate change in the next 2 decades?

A new decade question: given that the “mini ice ages” were triggered by volcanic activity, how likely is it that we will experience similar levels of volcanic activity over the next 20 years? In ...
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Centripetal Force Perfect Ball and Water

I made a question in WolrdBuilding as I was directed to. There a user said that with a perfect ball all water would pool to the equator because of centripetal force. What I do not understand is how ...
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Where can I find broadband seismic reflection data?

or what type of companies should I contact to ask for the data? This data would be produced from Seismic Vibroseis survey trucks which are mostly used to locate oil and gas. I doubt most oil and gas ...
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About climate sensitivity of carbon dioxide: today compared with PETM

Due to IPCC the climate sensitivity of CO₂ very likely is 3.0 ± 1.5 ℃ for each doubling of the concentration of atmospheric CO₂. Counting on earlier global warming using the Arrhenius formula [ΔT=λ·...
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Are there any geology only related educational institutions?

I'm not looking for college recommendations or which is the best, so I'm not asking for opinions on which institutions are the best. What I would like to know is if there are specific places that ...
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What is the history of atmospheric O₂ concentration?

(This is about O₂, not CO₂) How did the concentration of oxygen change? Over geologic time frames since plants began to produce it, and during the time since the carbon dioxide increase caused by ...
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How long could a steel artifact last?

Would man-made steel artifacts be able to be preserved like fossils for millions of years, or would corrosion make them dissipate? What about metals such as aluminum that don't corrode as easily?
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Inquiry, Is this Crystal? [closed]

I'm Erfan from Yemen, I found this stone in my village's mountain, it looks not normal stone, it's shinning like a crystal and headlight can penetrate it. There are hundreds of it in the mountain. ...
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Formation of Iceland

Iceland sits atop a divergent ocean-ocean boundary. But there are not many islands which are formed along a divergent boundary. Why is it so? Why do not mid ocean ridges often rise above the sea ...
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Origin of Andaman and Nicobar islands

Are Andaman and Nicobar islands in Indian ocean a continuation of Alpide-Himalayan orogeny or are they volcanic in origin?
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How can one find the true dip angle and quadrant when an apparent dip and strike is provided?

I am trying to solve the following question but cannot figure out how: A layer of limestone has a strike of East to West on a hilltop, and an apparent dip of 40 degrees on the vertical hillside ...
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Strength of Magnetic Field at Mid Point of a Reversal

As the duration of a magnetic reversal can be up to 12,000 years, could there come a time mid-way in the transition when Earth's magnetic field is as negligible as that of Mars or Venus? Magnetic ...
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What's the story of the shear face in the new Mac OS Catalina wallpaper?

The new Mac OS boasts a beautiful default desktop background with the western tip of Santa Catalina Island. The rock formation in the foreground looks like it was sliced on the diagonal with a power ...
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Paleogeographic Map

How do you construct a paleogeographic map with given sedimentary structures as guidelines?
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148 views

Can a braided fluvial create thick relatively continuous siltstone beds?

I am attempting to interpret an outcrop I went to. I suggested it was created by a braided fluvial. The one thing I cannot explain are prominent alternating siltstone beds with the sandstone beds. ...
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How did these dark lenticular features form? (Near Hoganekkal Falls India.)

These photos were taken near Hoganekkal falls in south India. The darker lenses appear to be the same rock type but have varying thickness and do not form a continuous layer. How did this structure ...
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Is this classification of mineral formation environments correct?

I am writing an app for students that consist in 180 sheets of the most common minerals on Earth's Crust. One of the fields of the sheets is environment of formation. It is important to me to ...
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Height of Everest from base to top

It's relatively well known that Everest is the highest mountain above sea level, and that Mauna Kea in Hawaii is the tallest mountain from base to top. But how tall is Everest from base to top? Or to ...
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Why was the temperature change greater in higher latitudes than in lower latitudes during the Paleocene/Eocene thermal maximum?

In the "Plankton cooled a greenhouse", which is the article written by Birger Schmitz, it is stated that the subtropical regions became warmer during the PETM(Paleocene/Eocene Thermal Maximum) but the ...
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Information on this rock, and identity? [closed]

My aunt gave me this rock. She has had for years. She was given it by a relative who passed many years ago. She said it was called a Tuffy (not sure which way it should be spelled) and that it came ...
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Calculate normal and shear stresses with fault plane dimensions, slip, orientation and regional stress tensor

I'm trying to verify that some code I have is running correctly when calculating the Coulomb stress change. So for a example I have a fault with : Length = 70 m, Slip= 0.004 m, Orientation(strike/dip/...
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How did this hole / hollow form within this rock?

Can you assist me in understanding how this hollow was formed in this rock. I am told that it has to do with cementation but I believe that geological process produces rounded canonball ( sometimes ) ...
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Could someone tell me what this stone might be [closed]

It is 9 1/2 inches by 3 1/2 inches and weighs about 5 lbs. it was at this house in Florida when we bought it. It has a white 1/4 inch crust and the interior color looks somewhat topaz.
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where are the poles of rotation of the tectonic plates located?

Euler's "fixed point" theorem ... can be stated as: The most general displacement of a rigid body over the surface of a sphere can be regarded as a rotation about a suitable axis which passes ...
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What Makes Round Holes In Superior Agates? [closed]

I found this rock in Western Wisconsin. Pretty sure it's a Lake Superior Agate? Wondering what would make the white eye that has red in its center? Would this rock be a good one to have someone cut ...
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Marks on boulders of volcanic origin

I am working in a catchment in the southern Ecuadorian Andes, about 3700 m.a.sl. Rock outcrops at the upper part of the catchment, as massive blocks varying their size from one meter up to five meters,...
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If two adjacent tectonic plates are moving in the same direction, is there significant interaction at the boundary?

If two adjacent tectonic plates are moving in the same direction, is there significant interaction at the boundary? Is it just a convergent boundary if one moves faster and "catches up" with the other?...
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Can an igneous rock have a Vp of less than 1000 m/s and need blasting to excavate?

I have run a 60 m refraction seismic line on a mountain summit. The environment was noisy (wind would be the principal agent) and quite difficult to pick first arrivals. It resulted in 800 m/s. A ...
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Is there any possible future for high energy geophysics? If so how it is going to revolutionize our knowledge about Earth's interior?

How practice is to map/image the subsurface of the earth using the high energy particles like neutrinos? https://www.geosci-instrum-method-data-syst.net/special_issue2.html
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Can living where magnets are abundant provide a mini-magnetoshere?

Are there a mini-magnetosphere within the magnetosphere similar to mini-magnetosphere found on the Moon? Is there a map of these areas that would resemble the white swirls in the picture below? The ...
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609 views

What is the History of the Brooks Range?

This here is a map of the Brooks Range in northern Alaska: As you can see, it is an inland range shaped in a downward curve. Why is that? What is the history of the uplift of the Brooks Range? How ...
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"Obicular" structures in basalts

I found spherical or globular structures, structures in basalts of a greenstone belt which underwent alteration and deformation. However, in thin section, these structures have undeformed pyroxene and ...
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Do earthquakes produce folds on rocks?

Earth rocks are frequently folded at surface. Folds in alternating layers of limestone and chert in Crete, Greece. Source: commons.wikimedia Are earthquakes the main mechanism ...
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Should I perform EOF analysis on an unevenly-spaced time series?

I have a dataset of sample concentrations of several ions/elements (Ca 2+, SO4 2-, K +, S, Ca, V, etc.) from an ice core which I am using to detect volcanic eruptions. The raw version of the dataset ...
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Is there limestone under the Oregon Coast Range?

I've found some diagrams of the Oregon Coast Range, but they are very basic. An friend said he thinks there is limestone deep underground, but my understanding of the formation of these mountains is ...
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Are sand deserts the greatest natural convection heaters on Earth?

Ask any climate scientist the question: "Why are deserts so hot in the day time and so cold at night" and generally you will get the same answer, it’s all about the lack of moisture and latent heat ...
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How Can We Establish Precisely What Earth's Core is Made Of?

The consensus view is that that the Earths core is composed mainly of iron alloyed with about 10 percent nickel and traces of other heavy metals, but I have seen at least one account which says it is ...
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How is the difference in crust and mantle composition explained?

We know that the composition of the crust is SiAl and SiMa and the one of mantle is mostly ophiolites, but why? Which are the geological processes that make this difference exist?
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How older is this snail shell possible could be?

Last weekend I was in Xınalıq(the village in Azerbaijan) and found this snail shell. I am wondering how old is this?
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Climate consequences of very large asteroids striking the Deep Ocean

For every asteroid or meteorite that hits dry land, two hit the sea. If a Manicouagan-sized asteroid struck the deep ocean (but not above a trench),how would the H2O vapour, chlorine, iodine bromine ...
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Could the Grand Canyon be flooded by the ocean if it got deep enough?

The Colorado River has been carving the Grand Canyon for a few million years now, such that the canyon floor is around 6000 feet lower in elevation than the surrounding area, at about 2400 feet above ...
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Peninsula vs Cape [closed]

I know that Peninsula is much larger than a cape, but is there a definite way to differentiate them? I.e. by area- if the total area is larger than 30 sqkm, any headland is classified as peninsula..
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Why can't we dig deeper?

I recently read on another SE site that there's a limitation on how deep we can dig into the earth. A Google search reveals that temperature is the problem. I quote from a Popular Mechanics article ...
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Is there a widely accepted reason for the formation of tafoni?

Expansion of tafoni seems to be based on weathering (seems reasonable enough.) But what creates them in the first place? There are a number of explanations online (Wikipedia lists eight plausible ...

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