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.

Filter by
Sorted by
Tagged with
1
vote
0answers
36 views

Where and how big was Sicily between 5 and 1 Ma ago?

Sicily is a geologically complex island which seems to have been extensively studied geologically and from a tectonically point of view. There are an overwhelming number of papers dealing with the ...
3
votes
1answer
60 views

Why isn't Iberia a tectonic plate?

I usually read that Iberia is a subplate, while India is a plate. But it was a plate at the beginning of the Alpine Orogeny: Source: wikimedia.org Description: Tectonic map of southern ...
0
votes
0answers
31 views

What are the favourable conditions for the formation of porphyry copper deposits?

Favourable condition for the formation of porphyry copper deposits is : 1. Extremely low oxygen fugacity in initial magma 2. High water content in initial magma 3. Crystallization of magama at deep ...
5
votes
1answer
37 views

Sources or strategies for stone identification

I have a bunch of semi-precious stones here, but I am not very learned in geology etc and I would like to have some way to know what kind of stones they are. As far as I understand question about ...
4
votes
1answer
52 views

Luis Alvarez's K-T Impactor Calculation

I am trying to perform the calculation that Luis Alvarez used to establish the size of the K-T impactor. I used the following information: Assume that the clay layer with iridium was uniformly ...
3
votes
1answer
69 views

What ore minerals are likely to be found in a thin section like this? What can we deduce from the structure?

The following image is of polished sample of mineral-rich rock. There are two major portions we can see that is ore minerals and rest the grayish material is gangue. The photo was taken with an ore ...
4
votes
1answer
67 views

How are stratigraphic limits defined before the Phanerozoic?

International Commission on Stratigraphy defines the limits of geological ages and they create this chart: Click on image for full view. Acording to Wikipedia: The standard stratigraphic ...
2
votes
0answers
25 views

Faster shale velocities in deviated wells

I am currently working with sonic measurements in the wells and there is an observation, that velocities are faster in shales over the deviated parts of the well. So, when the relative dip between the ...
2
votes
2answers
54 views

What are the key elements defining the separation between Jurassic and Cretaceous?

We have one mass extinction that seperates Trias from Jurassic, roughly huge volcanims over a long period of time, and Pangea starting to divide. Another mass extinction that marks the end of ...
2
votes
2answers
94 views

Introduction to Geology Books

I am a high school student who is thinking about going to university for Geological Sciences. I've had an interest in rocks and such since I was little, but I want to get an idea of what studying ...
5
votes
2answers
74 views

Do we know what the rigid mantle looks like?

The rigid mantle, which is hard and lies above the asthenosphere, is separated from the "crust" that we can see and touch by the Mohorovičić discontinuity. Wikipedia provides an image of what may once ...
36
votes
3answers
7k views

Does gravity increase the closer to the core you get?

Or does the mantle and crust above you counteract the increase at one point and it actually decreases?
5
votes
0answers
35 views

Are there any known global effects of the Mediterranean sea evaporation and refilling?

This is a broad subject I realize, but I'm looking for specific geologically observed answers of global effects elsewhere, between about 5.96 and 5.33 million years ago when the Mediterranean sea was ...
2
votes
1answer
73 views

Can we separate a sandy, clayey & salt layer on basis of their rheological properties?

Since, given enough compaction, salt is able to behave like a fluid & buoyant too if it's overlain by a higher density rock (it could be fine grained clay or a sandy sequence). But in another case,...
1
vote
2answers
151 views

How to genetically classify a mineral resulted from weathering?

I am writing a mineral guide for smartphones which classifies minerals according to their formation environment. From sugestions on this related question, I changed the classification to: ...
2
votes
0answers
32 views

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( ...
3
votes
2answers
96 views

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,...
6
votes
0answers
27 views

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 ...
13
votes
3answers
2k views

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 ...
6
votes
2answers
205 views

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 ...
2
votes
0answers
58 views

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, ...
1
vote
1answer
141 views

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 ...
1
vote
2answers
112 views

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 ...
0
votes
0answers
28 views

Finding Outcrop Pattern from Outcrops / 3 point problem

On the below (rough) example, how would I go about finding the outcrop pattern? I'm aware of the following procedure: Link highest and lowest outcrop to give strike line Find the actual dip using ...
0
votes
0answers
24 views

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 ...
1
vote
0answers
123 views

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·...
0
votes
1answer
57 views

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 ...
2
votes
2answers
119 views

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 ...
3
votes
4answers
1k views

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 it dissipate? What about metals such as aluminum that dont corrode as easily?
1
vote
0answers
52 views

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. ...
3
votes
3answers
128 views

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 ...
1
vote
0answers
28 views

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 ...
2
votes
0answers
36 views

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 ...
3
votes
1answer
66 views

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 ...
0
votes
1answer
49 views

Paleogeographic Map

How do you construct a paleogeographic map with given sedimentary structures as guidelines?
3
votes
1answer
110 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. ...
3
votes
1answer
119 views

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 ...
2
votes
2answers
127 views

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 ...
-1
votes
2answers
88 views

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 ...
1
vote
0answers
24 views

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 ...
0
votes
1answer
42 views

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 ...
1
vote
0answers
37 views

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/...
4
votes
1answer
59 views

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 ) ...
0
votes
1answer
50 views

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.
2
votes
2answers
82 views

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 ...
2
votes
1answer
55 views

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 ...
3
votes
1answer
33 views

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,...
1
vote
2answers
79 views

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?...
2
votes
1answer
68 views

Can a 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 ...
3
votes
1answer
52 views

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

1 2 3 4 5 13