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Questions tagged [radioactivity]

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Natural nuclear explosions

I'm aware of the Oklo reactor and other natural nuclear fission reactors, in which geological processes can lead to the formation of a sustained, self-regulating uranium fission reactor. Is it also ...
21
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2answers
2k views

Why does phosphate rock contain uranium?

I have been doing some research on the issue of phosphogypsum pollution. Phosphogypsum is a waste by-product formed with the "wet process" method of extraction of phosphoric acid out of phosphate ...
17
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3answers
7k views

If 75% of radioactive material remains, how many half-lives have elapsed?

Radioactive element A radioactively decays into material B. If 75% of A and 25% of ...
12
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2answers
555 views

How does radiogenic argon-40 get into the atmosphere?

There's an awful lot of argon in the atmosphere: about 0.93% of the atmosphere is argon[1], making it the third-most abundant gas after N2 and O2. As I understand it, most of it is produced by the ...
11
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1answer
181 views

How can scientists be confident of isotope ratios in past eras and varied locations, used for radiometric dating?

Radiometric dating relies on past isotope ratio predictions being very reliable. However, this is not necessarily so. For example, in Uranium forensics, 235U and 238U ratios are about the same for ...
10
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1answer
246 views

Rate of underground formation of carbon-14 by neutron capture

Carbon-14 constantly forms in the atmosphere due to neutron capture by nitrogen-14 and subsequent emission of a proton. Other less frequent mechanisms involving neutron capture by carbon-13 or oxygen ...
8
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2answers
263 views

Do fluctuations in radioactive isotope decay rates affect carbon dating techniques?

In 2010, Purdue University published a research paper[1] stating that their researchers had detected slight fluctuations in radioactive isotope decay rates "in synch with the rotation of the sun's ...
7
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1answer
237 views

Are Helium 3 and 4 being produced by earth's core?

J. Marvin Herndon claims that the evidence of the georeactor comes from 3He/4He ratios released to the oceans at the mid oceanic ridges. Georeactor-produced 3He/4He ratios are related to the extent of ...
6
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1answer
347 views

Does Earth's magnetic field arise from a fission reactor in its core?

I heard about the georeactor hypothesis (Herndon, 1993), which claims that there is a natural atomic fission reactor in the Earth's core giving rise to the geomagnetic field. Further, Herndon claims ...
4
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3answers
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How do we know how much Uranium was in any given sample when it was deposited?

Concerning "Uranium-series dating", also known as "Uranium-thorium dating". Uranium is present in deposits, "typically at levels of between a few parts per billion and few parts per million by ...
4
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0answers
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Possible Effects of a Nuclear Reactor Breach in the Mediterranean

Double-barreled question which may not precisely belong here! Input nonetheless greatly appreciated. My question: To what extent would a nuclear reactor breach in the Mediterranean sea affect the ...
3
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1answer
53 views

Giem's article on carbon dating

I don't want to start any controversy. I'm just curious about what could professional geologists say about this paper, and what is it's current scientific status, since I couldn't find any serious ...
3
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1answer
58 views

gamma-ray spectrum vs energy decay

I am going through An Introduction to Applied and Environmental Geophysics, a book by John Reynolds (2011), to better understand radiometrics and gamma-ray spectrometry. The author provides some ...
3
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1answer
103 views

Why can isotopes reflect the age of the Earth rather than the age of the supernova that created them?

Radiometric dating is based on heavier elements decaying into lighter elements, for example uranium decaying to lead. But wasn't all uranium in the Solar System created in one or more supernova? And ...
3
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0answers
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How do people determine initial ratio of the parent nuclide and daughter product in radiometric dating?

I understand that we have zircon crystals that prevent entering or leaving of nuclide or lead after forming. But how cand we understand what was the initial ratio?
2
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2answers
143 views

Radiometric dating data sets

I am in the process of learning what sort of data is collected with radiometric dating techniques, used for absolute dating. It sounds like there are two primary ones: Radiocarbon dating (~50k year ...
2
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1answer
43 views

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 ...
0
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2answers
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Is there any correlation between Australia's uranium deposits and the unique animals?

Australian animals are very different than the rest of the world. I wonder if the radiation of Australia's Uranium deposits have anything to do with why animals uniquely evolved? For instance, ...