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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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Can someone identify this geode found in upstate NY

Can some identify this geode? It was found in upstate New York in a flat sandy plain 1/4 away from the Hudson River. The geode is approximately 3" long, brown exterior, 1/4" "shell" gray , and 1 1/2" ...
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2answers
3k views

What is the average color of dirt?

Where I live the soil is red. Is there a map or chart where you can see the average color of the dirt according to geographical location? What would the color be if all of the dirt on Earth was ...
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1answer
62 views

What kind of stone is this?

Years ago, I bought from a flea market two strange looking stones, that the owner said he had found under the sand of a dune in the desert (I don’t remember which). Maybe it’s true, maybe not, but I ...
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2answers
1k views

At what depth does the underground begin to warm up?

Spring water comes out colder from being underground. But if you get deeper the temperature goes up. At what depth does the underground stop getting colder and begins getting warmer? Is there a map ...
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1answer
146 views

Is this deep green calcite, green gneiss stone?

The site where it is found is characterized by schist, quartz and gneis, but also other species of rock. This is a scissors 2 cm semi transparent, vitreous luster, hard scale 6.5 - 7 ... I will post ...
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1answer
68 views

How does the synthesis of Kaolinite (and it's by products) influence porosity in granodiorite?

I started studying the effects of weathering on granodiorite (see previous posts) and plan on referencing the link between the chemical weathering of feldspar plagioclase leading to kaolinization, a ...
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1answer
59 views

Can someone help me identify this rock please?

I recently found this at a garage sale and I would love to know rock this is. It weights 6 lbs. -Thank you
6
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3answers
345 views

In an Earth-like planet with no history of carbon-based life forms, would there be limestone?

The extent of my understanding of limestone is about what Wikipedia says at the very top of the page: Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such ...
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1answer
56 views

Please help me identify these two rocks? [closed]

Two rocks both green, one is transparent, the none transparent rock is extremely tough almost impossible to cause a scratch on it. Thanks
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1answer
162 views

Why would CaO be more finely spread than K2O in Granodiorite?

I recently interpreted some XRF data on samples of a granodiorite which were classified under three different types of physical characteristics: very little, mild and significant levels of weathering. ...
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1answer
56 views

Help identifying rock?

Found in stream, heavy, has a tin of red lines and dark. 1]]2[grey white, rusty ]3. Dark lines n rusty lines. Hard to break off piece ain't magnetic
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0answers
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What are those flat areas in this desert formation seen from orbit? [duplicate]

(Google Earth at 19°58'49.87" N 53°38'09.51" E) Related to: What produces these distinct shapes in the Rub' al Khali seen from space? What is the flat (?) green/blue-ish terrain in between the ...
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1answer
117 views

What other graphical methods can be used to represent weathering?

Context: For one of my reports I have taken samples of a rock from an adjacent creek. I have done XRD analysis to get compositions of calcium, potassium and aluminium. My question: I know about ...
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1answer
130 views

Ocean water coming from Mantle vs coming from meteorites

Posibly duplicate from Water on Mars and Earth I remember well a hydrology course where our teacher made some calculations of the total flux of water from Mantle ejections in Earth's history. He ...
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1answer
37 views

What's a reasonable flow rate/mass flux for a fumarole?

Obviously, there is going to be a large amount of variability, but what are some realistic values?
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1answer
75 views

Can someone identify this 'striped' stone? [closed]

The stone has a raised texture on the top where the stripes are. I'm not sure exactly where it was found. It is not magnetic.
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2answers
410 views

Why do the earth sciences use mega-annum instead of mega-year?

I've noticed that geology and related fields use mega-annum (Ma) instead of mega-year (Myr) as the unit for 1 million years. Why is that? Is an "annum" different from a "year" in geology?
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0answers
52 views

Is there a large undersea caldera in the Azores?

There looks like a large undersea circular feature (Google maps) about 120km across with its north edge on Sao Miguel Island and its south edge on Santa Maria Island. Has any work been done to say ...
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2answers
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Is there sand in Antarctica?

There's a song "Blizzard's Never Seen the Desert's Sand". Given Antarctica is a desert, someone questioned the title's validity. BUT is there sand in Antarctica? I'd imagine yes as it's a pretty ...
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3answers
83 views

Need seismic data and digital well log data from the same area?

I am currently working on a project that involves the input of seismic attributes (instantaneous amplitude, instantaneous frequency etc.) to a machine learning/deep learning model (eg. A Neural ...
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1answer
37 views

Is there any rule of thumb to decide the indentation hardness test?

How to decide whether Brinell Hardness test, Rockwell test or Vicker's test is to be applied as far as grain-size is concerned? Is there any rule of thumb to decide the type of indentation hardness ...
3
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1answer
174 views

Open source well information viewer

I am in the middle of a hobbyist experiment and would like suggestions on an open source HTML viewer for mud loggging, FMIs, lithology and seismic. I have used INT before but for this project I would ...
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2answers
201 views

What kind of rocks are these light-colored ones with shiny metallic inclusions?

My dad found these rocks in his garden. They have some shiny metallic looking pieces in them. Would anyone be able to identify what they are? We live in South Africa if that helps. Thanks!
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3answers
578 views

Help! Can anyone identify this deep blue rock, quartz, crystal thing from Washington?

I was like 10 waiting for my dad to get off work. He was a surveyor and brought this blue rock thing with him for me when he got off. He said they were surveying and his friend took a pickax to a rock ...
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0answers
230 views

What kind of rock/mineral is this pinkish stone I found in Colorado?

I found this in my backyard and would love to know what I'm looking at. It reminds me of a fossil. I live in Colorado, Denver-metro. The sample is about 2 inches top to bottom, weighs maybe .5 lb, ...
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1answer
380 views

Is this platinum ore? Mohakite? Found in Michigan

This was found in a river in southeastern Michigan. It is very light (about 14 grams) and not magnetic.
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45 views

Interpretation of horizon display

I am currently working on a project that involves using seismic attributes as input parameters in a neural network for estimation of porosity and permeability for a reservoir. Now, I need to correlate ...
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1answer
196 views

What is this waxy sort of green rock from Labrador, Canada?

This rock is green and kind of waxy to touch 1: https://i.stack.imgur.com/WKBVU.jpgWith a nail you can scratch it but not deep and it is kind of dull with shiny specks in it,it do seem like layers or ...
6
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2answers
142 views

Please help me Identify this rock

I am not an avid collector but I found a rock that was really out of place and have had it for 40 years now. So...basically, it's about time to figure this out. I found it in a field on the east side ...
4
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1answer
149 views

How are the Scala dei Turchi staircases formed?

The Scala dei Turchi i (Italian: "Stair of the Turks") is a rocky cliff on the coast of Realmonte in Italy: https://en.wikipedia.org/wiki/Scala_dei_Turchi#/media/File:Scala_dei_Turchi_panorama.jpg ...
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1answer
77 views
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112 views

Presence of cross stratified conglomerates in fan deltas

Why are cross stratified conglomerates found in deposits of fan deltas? I know that fan deltas are alluvial fans that deposit directly into the sea, hence they are poorly sorted.But could not ...
5
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0answers
213 views

How are chenier ridges and strand plains formed at wave dominated coastlines?

In the attached image, we can see chenier ridges and strand plains. How are they formed and what is the involvement of rip and longshore currents in their formation?
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1answer
375 views

Concept of artesian aquifers and pressure is not clear.

I do not understand how the Artesian aquifer is causing the water in the flowing well to reach a level higher than the ground surface? And what role does the piezometric surface play in it?
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0answers
71 views

Can the process of subduction flatten the shape of a subducting plate relative to the plate it's going under?

There's something I’m still not quite getting about why island arcs are arcs. In the examples I’ve seen, the subducting plate is compared to a knife slicing across the surface of an orange - but it ...
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2answers
76 views

What is this brown rock?

What type of rock is this? Anyone?
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1answer
54 views

How many extreme shifts in climate has Earth gone through in its existence?

As the Earth formed, it went through cycles of essentially hotter and colder periods. Extremely volcanic times and ice ages, in feedback loops contributing to one another. CO2 swinging from high to ...
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25 views

Detecting the hydrothermal alteration zones?

Is it possible to use remote sensing to determine Hydrothermal alteration zones without resorting to collecting samples from the Area of study?
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1answer
631 views

How vertically deep do lava conduits go?

I'll preface this with the truth and hope it doesn't disqualify the question but rather give context: after reading Journey to the Center of the Earth by Jules Verne, I am amazed at the prospect of ...
4
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1answer
86 views

Utah rock pattern identification - looks like small craters

This formation was found in the Capital Reef area of Southern Utah (38.2970546, -111.2979319). There wasn't just one, but several of these small crater formations all over the area. All of them had ...
2
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1answer
56 views

What are “x-cutting relationships”?

This tweet by Daryl Blanks asks: Day 1 VTMR trip @GeologyLeics -First stop Laxford bridge! gneiss with amphibolite and granitic pegmatite intrusions - can u spot all x-cutting relationships?! What ...
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1answer
85 views

At what rate does Earth's atmosphere shed heat into space? [closed]

If we had a heat bank account (the atmosphere) + heat cash supply (ice) + heat debt (the oceans) could governments find a way to balance our heat economy that doesn't kill ...
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0answers
37 views

How long will it take for plate tectonics to shut down and what will the effects be? [duplicate]

As the interior of the earth cools, presumably there will come a time when the temperature gradient is insufficient to maintain the mantle plumes and hence plate tectonics. How long will this take ...
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1answer
92 views

How old are Chile's fjords?

Do we have any knowledge about the age of Chile's fjords, more specifically, those found near the Northern Patagonian Ice Field? Is it reasonable to conclude that they were formed in Quaternary given ...
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1answer
144 views

How can I tell the difference between granite and syenite?

(I'm not a geologist, just helping my kids collect rocks).
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1answer
257 views

Is altitude of everything decreasing due to sea level rise?

We know that sea level is rising, though some people say climate change is fake. Altitude is defined as the height of something measured from sea level. Since sea level is increasing, and the ...
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0answers
46 views

What is this dull whitish rock with ornate black patterns found in the Arkansas Crater of Diamonds?

I found this rock while wet sifting dirt brought back from the Arkansas Crater of Diamonds. It looks as if it is hand painted. It is smaller than my pinky nail. It’s dull, and makes a chalk-like mark ...
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1answer
59 views

What is the motivation behind the choice of unglazed Porcelain as a Streak plate?

What characteristics does Porcelain possess that makes it a good choice for the Streak test? Additionally, are there any other materials that could also be used for designing a Streak plate?
2
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1answer
201 views

Movements of the tectonic plates - collison between Indian Plate & Eurasian Plate

I am a high school student, my question is about the collision between the Indian Plate and the Eurasian Plate. When this happens what happens to the area of the Asian continent. Does it increase or ...
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How did CO₂ originate on Earth before there was life?

To start life there has to be $\ce{CO2}$. $\ce{Solar energy + 6CO2 + 6H2O -> C6H12O6 (sugars) + 6O2}$ $C_6H_{12}O_{6} + O_2 \longrightarrow H_2O + {CO}_2 + \text{Energy}$ So to start this cycle, ...