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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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How do hematite and magnetite form?

I want to understand the conditions under which hematite $\ce{Fe_2O_3}$ and magnetite $\ce{Fe_3O_4}$ form in nature. The linked Wikipedia articles explain various conditions under which they form, but ...
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1answer
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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
50 views

Carbonaceous Chondrite [closed]

Can you please help me identify this rock? Is it a meteorite; if so, what kind? I sought the advice of the only scientist I know, but geology is not his primary field. He suggested a mineralogist ...
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Did an impact crater cause the formation of the gas fields in north eastern South Australia

In the paper High Impact Reservoirs, the authors claim that impact craters have lead to both the creation and destruction of petroleum source rocks, reservoirs and traps. Recently it was announced ...
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1answer
122 views

Identification: mystery rock with golden features and shimmer

I found this rock in our backyard in Germany. As our garden is filled with bushes it was very oddly placed and I have carried this rock around with me ever since, wondering what sort of rock it might ...
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1answer
151 views

Identify yellow-tinted translucent mineral

I found a mineral near the hexagonal rock formations in High Island, Hong Kong that I'd like to get ID'd. It has a greasy and subadamantine lustre. It can scratch a U.S. Quarter Dollar and some types ...
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1answer
136 views

What is diffuse plate rifting?

For example in the Philippine Sea Plate the West Marianas Ridge has formed due to diffuse rifting in the south of the Marianas trough. What does it mean?
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2answers
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Hypothetically, what would happen to the earth if a large hole was drilled through the center?

This may be a slightly unusual question. I know it wouldn't be possible, but what would the short and long term effects be, if a large (say, 1 mile diameter) round hole appeared, and went straight ...
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1answer
81 views

What is this rock. Solid, Heavy, Metallic. Unknown origin

A few weeks ago i found this rock in the geology collection cupboard that my Geography teacher inherited from his predecessor. It is numbered 3729 but no list exists of the collection so we can not ...
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52 views

Which is naturally more radioactive: a tertiary or cretaceous sandstone? Why?

I've come across this question in a Petrophysics exercise regarding the Gamma Ray well logging. And I don't know how to solve it. This is the "believed" AFAIK session Natural radioactivity on a ...
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1answer
71 views

Please identify- no origin known but given to me by a geologist

A very dear man who love his job as a geologist gave this to me. He’s been all over the country so I have no idea where he may have picked it up
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1answer
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would someone be so kind as to identify this rock i found? [closed]

What is this rock I found, it's got little glittering things on it. I found this in Sussex county New Jersey, it was used to line my driveway with a bunch of other rocks, other than that I don't know ...
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1answer
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Where to start searching to find more radioactive minerals?

I'm pretty new to all this... I've recently purchased a Geiger counter, and am hoping to locate rocks like pitchblende and other radioactive minerals for my collection. I'm based in the North West ...
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0answers
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how best to preserve the color of my amethyst geode?

Will bright indirect light cause an amethyst crystal to fade? How about an overhead LED light? How is best to preserve the color of my amethyst geode? Thank you!
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2answers
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Please help identify this! Rock? Glass? Crystal? It's big and very heavy [closed]

About 1.5 feet tall, 1 foot deep and 2 foot wide. Very heavy and very hard. I will get a better picture posted asap. You can read a newspaper thru it. Was left to me by my uncle years ago but never ...
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1answer
82 views

Please explain how this rock could be shaped like this [closed]

i found this amongst some river rock. Please explain why or what happened to it.
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1answer
175 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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1answer
94 views

Using acoustics to measure the composition, density, and hardness of layers

I am an engineering student at Alfred University and some fellow classmates and I are doing a competition, but one of the tasks we need to complete is autonomously measuring the composition, density, ...
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4answers
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Is it a lunar meteorite? [closed]

I have found this rock in Moroccan desert density 2g/cm3.
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1answer
59 views

Asking about type Fossil [closed]

Can any one help me to identify this type of fossil ? Its dolomite limestone
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2answers
321 views

What is this complex reddish-brown stone with lighter spots found at a NZ beach?

I found this small stone on a beach on the east cost of the North Island in New Zealand. It's red/brown and has almost gray spots, but also has lots of white crystals coming out of it. It has a dull ...
2
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1answer
61 views

The magnetite is in which type of magma

In which type of magma can I find magnetite? Peraluminous or peralkaline? I've been looking and the peraluminous magma have a lot of oxides so I thought it would be reduced magma so it would have ...
5
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1answer
202 views

How does palingenetic fusion occur in rock?

As far as charnockites are concerned, granitic charnockites are formed due to palingenetic fusion and metasomatism, while granulitic charnockites are formed due to high grade metamorphism. When I ...
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1answer
94 views

What are these Pebbles

Found these Pebbles at a lake edge where a Serpentinite belt runs through, there are lots of serpentine pebbles along this lake in Co. Sligo Ireland. The larger pebble is 1 5/8'' a Yellowish white ...
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0answers
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Identification of a rock. White marble? [closed]

Could you please help me identify the rock found commonly near many of the ancient Greek foundations and rubbles? This one was at the base of Poseidon's temple. White in colour with a smooth texture ...
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2answers
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What is the identity of this heavy, smooth, shiny black and red rock? [closed]

. It's very shiny and layered. It has rough texture but spots with smooth red colored pieces.
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1answer
436 views

What kind of green rock is this? [closed]

Just wondering what kind of rock this is. I found it near an old home that was built in 1882 in Kansas. It is very heavy and it has a dark green tint to it. Probably about 6 lbs.
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2answers
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Help me figure out what this purple rock is

I found this in the ground at a job site in blue springs mo . Its purple with darker purple lines through it like growth marks on a tree. It is about the size of a large loaf of bread 7 inches across ...
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2answers
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I found this strange spherical stone in Gillette Wyoming. I have no idea what it is. Please help.

These are recent pictures of it. It’s heavy, I see small minerals that catch the light in it, very bumpy, spherical, doesn’t seem to be magnetic, I was falling down a deep trench and kicked it up at ...
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1answer
63 views

What kind of purple stone is this?

I found this stone and I do not know what type of stone is this?
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1answer
221 views

heavy, brown, rock with crystals, please help identify

please help identify this rock. it is heavier than most. dark brown color. picture is shown with streak test. found in Philadelphia pa. at home demolition site. crystals seem to be different type and ...
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0answers
501 views

Definitive values that classifies a rock as having “low”, “medium”, and “high” -strength, -hardness, -toughness, and -consolidation?

Question: Are there any widely accepted published values (or ranges) that classifies a rock as having “low” “medium” “high” -strength, -hardness, -toughness, and -consolidation (cementation or ...
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1answer
349 views

Mineral Rock Identification

Went out hiking after some heavy rains and came across an area that looked like broken glass sticking out from mud. On a closer look this is what we found. Not sure what it is and would like to know ...
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1answer
793 views

Rock ID: shiny, very hard, black rock from Louisiana, USA

I have had this for over 20 years and I still don't know what it is. I found it on top of the ground by my dad's workshop in our yard in Louisiana. I don't know how it got there. It weighs 6 pounds 7 ...
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1answer
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What is this rock found in the Illinois Valley of Southern Oregon?

I found this odd shaped rock along a rocky river bed (dry) near the Illinois river in Cave Junction, Oregon. It is shaped like a Club and is super heavy. It has a distinguishable ring around the ...
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1answer
157 views

Is astrochronology a proper method?

Wikipedia's definition of astrochronology is: "Astrochronology is the dating of sedimentary units by calibration with astronomically tuned timescales, such as Milankovic cycles,1[2] or even ...
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3answers
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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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1answer
68 views

Please help identify

I have had this rock in my yard for close to 10 years. It was left behind by the previous tenant. Can you help identify it? It has layers, a mixture of soft and hard, and is tan to white in color. ...
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99 views

Rock identification - origin unknown

I'm trying to identify this rock. It's fairly fine-grained and has a green tint. It's fairly heavy for its size, I cannot scratch it with a figernail but I can make a scratch with a knife. The rock is ...
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What types of stone are these rocks I found in Scotland

Please could someone tell me what type of stone this is I came across it while walking my dog. I'm in the highlands of Scotland!
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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
79 views

Rocks sparking under water

I have searched for an answer to this question for years, to verify if it was true. A man that lived on a river in the rugged part of the northern Washington Cascades told me an interesting story. He ...
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1answer
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Historically, how did the total amount of salt / NaCl on Earth develop?

After reading this question about the origin of NaCl on Earth, I'm wondering: How did the amount of NaCl develop historically? Is it a more or less linear growth until today? Was it such a linear ...
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2answers
341 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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How do I generate a Moho depth model from seismic refraction data?

There are several permanent seismograph stations in Eastern Canada that have been recording arrival times for over 25 years. Using refracted Pn arrival times from natural earthquakes I would like to ...
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1answer
124 views

Seeming correlation between time of day and earthquakes

I live in a generally geographically active area (Southern California, near the San Andreas fault, if that matters), that has had two relatively minor earthquakes that I have felt in the last week (in ...
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1answer
883 views

Math needed for Hydrology, specifically surface water hydrology

I wanted to know what math is needed for hydrology, in particular surface water hydrology. In my research online, of Master's programs (either in Hydrology or Environmental Science with a ...
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2answers
120 views

What caused this waterfall to have rounded formations?

This is at Bua Tong Waterfalls in Chiang Mai, Thailand. Tried to find scientific information about this waterfall, but google turns up only travellers' vague guesses, suggesting calcium carbonate ...
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2answers
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Time of concentration - Difference between large and small basins

I am looking for any academic reference (i.e. articles) regarding the time of concentration for large and small basins. E.g. I would expect that a large basin (area > 1,500 km^2) will flood (or reach ...
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1answer
317 views

Please identify this pink transparent stone?

Pink transparent stone it maybe obsidian but my research indicates pink colour is very unusual for obsidian It’s translucent, all pink, slightly refractive you can read letters through when stone is ...