19 votes
Accepted

Why does phosphate rock contain uranium?

To understand why sedimentary phosphate rocks (hereafter referred to as phosphorites) have elevated uranium contents we first need to understand what are they made of and why do they form in the first ...
  • 22.4k
13 votes

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

The conventional explanation for the Earth's magnetic field is that some combination of differential rotation and/or convection occurs in the Earth's outer core, primarily in molten iron-nickel (+ ...
8 votes

Could a natural fission reactor form in Cigar Lake?

Given that the Cigar Lake uranium deposit is already buried beep, at 450 m below the surface, a "sedimentary carbon" deposit will not be deposited anywhere close to the uranium deposit. The ...
  • 22.1k
7 votes
Accepted

How does radiogenic argon-40 get into the atmosphere?

As the previous responder noted, the continental crust forms a large reservoir of potassium. Much of this is in the form of feldspar. My answer primarily addresses this continental crust source. To ...
  • 4,349
6 votes

Is radiocarbon dating based on assumptions?

First modern carbon dating does not assume constant Carbon isotope ratios, in fact it is calibrated against known changes in atmospheric concentration, and has been since the 90's. These baselines ...
  • 6,600
6 votes

Giem's article on carbon dating

The cited paper, and ones like it, are young earth creationist nonsense. The Geoscience Research Institute is an arm of the Seventh Day Adventists, whose official position is that "in a recent six-day ...
  • 20.8k
5 votes

Is there any correlation between Australia's uranium deposits and the unique animals?

No. The reason for Australia’s unique evolution is that it was relatively isolated from the rest of the world. Australia isn’t too radioactive either. The fact that it has more uranium deposits than ...
  • 22.4k
5 votes
Accepted

In radiometric isochron dating why is at t=0 D*/Dref=const but P/Dref not?

1) D* (radiogenic isotope) and Dref (stable reference isotope) are two isotopes of the same element. P is the radioactive parent of D*, and is a different element. Chemical fractionation between P and ...
  • 771
4 votes

Why does radioactive dating work on specific rocks?

There are other, mostly chemical processes which alter the isotope ratios. Isotope dating uses a combination of them. This is why it can not be used always, for any radioactive isotopes, only in ...
  • 660
3 votes
Accepted

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

Suppose you purify a sample of uranium 238, removing all of the lead. Half of those U-238 atoms will have decayed into lead 4.468 billion years from now. If the lead is removed from that half-uranium/...
  • 20.8k
3 votes
Accepted

gamma-ray spectrum vs energy decay

I will first focus on the 214Bi decay. The 3.272 MeV is the total amount available for the β- decay, i.e. the difference between the ground states of 214Bi and 214Po. If you have a beta decay ...
3 votes
Accepted

Radiometric dating data sets

It sounds like there are two primary ones: No, these are not the two "primary ones". The method used depends on what you are dating, and what age you expect it to be. Radiocarbon dating is relevant ...
  • 22.4k
3 votes
Accepted

Is there any correlation between Australia's uranium deposits and the unique animals?

Ahhhh, probably not. If, for example, you navigate to Marsupial at Wikipedia and click on the wonderful (it really really is!) DyMaxion map at the bottom of the info panel, you wiil see that a large ...
3 votes

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

Are Helium 3 and 4 being produced by earth's core? tl;dr no. The paper you are referring to has major flaws in it. Claims that should not be in any respectable scientific journal such as: ...the ...
  • 22.4k
3 votes
Accepted

Why does radioactive dating work on specific rocks?

Weren't all the natural radioactive isotopes created during the formation of the solar system? The half life of carbon 14 is 5730 years, orders of magnitude less than the age of the solar system. ...
  • 20.8k
2 votes

Why does radioactive dating work on specific rocks?

Radioactive dating works on specific isotopes we use for specific time frames. Rubidium–strontium dating methods (because this substance has a half life of 50 billion years) to date extremely old ...
2 votes
Accepted

How can radiometric dating of meteorites determine the age of the earth? Wouldn't this only determine the age of the decaying nuclide in each rock?

Many of your questions are answered in this question and associated answers: Why is Earth's age given by dating meteorites rather than its own rocks? To add to some of your other questions: ...
  • 22.4k
1 vote

How much role does radioactivity play in making Earth geologically active

The idea that the heat of the earth is from the time of its formation dates back to the late 1800s before radioactivity was known. Unfortunately for that theory it was shown that an initial blob of ...
1 vote

Have we looked for human-like signals in the geological record?

Any nuclear activity would be visible in the changes of the isotope ratios far longer than the existence of our Universe. Nothing was found until now, except one in Gabon. It was natural phenomenon: ...
  • 660
1 vote

Does the relative abundance of radioactive isotopes reflect their half-lives?

While a long half-life, hundreds or millions of years or more, favors a radioisotope being relatively common or even occurring in nature at all, it is not the only consideration. Whether and how ...
  • 2,726
1 vote
Accepted

Independent sources of information on radiation pollution in Europe

Two websites I've come across that might be of interest are: Radioactivity Environmental Monitoring Joint Research Centre, for Europe. Radmon.org which provides radiation information from number of ...
  • 22.1k
1 vote

Potassum-Argon Dating and Proportions of Daughter Products in Potassium 40 Decay Channel

Potassium 40 has a half life of 1,300,000,000 years, which means that within that time half of the 11 percent which you refer to will have decayed to form Argon 40. Potassium 40 has two modes of ...
1 vote

Radiometric dating data sets

There are huge datasets of geochronology available in the published literature. Unfortunately there is not one single database because the task is daunting (there are several thousand geochronology ...
  • 771
1 vote

Where to start searching to find more radioactive minerals?

You can try using the locality list at MinDat. Go to places that are easily accessible to you and see what minerals have been reported there. If there's something radioactive, it will probably be ...
  • 22.4k
1 vote

How do we know how much Uranium was in any given sample when it was deposited?

The field of nuclear physics has established the radioactive decay series for radioactive elements (see here as well). Unlike Uranium 238, Uranium 234 is not primordial nuclide. It is a indirect ...
  • 22.1k
1 vote

How do we know how much Uranium was in any given sample when it was deposited?

The chemistry of lead is very different from that of uranium and thorium. There are key kinds of rock that could not possibly have been formed with even the smallest amount of primordial lead. The ...
  • 20.8k
1 vote

Rate of underground formation of carbon-14 by neutron capture

I do not have access to the article you cite for the deep subsurface neutron flux but I question whether either article will be particularly useful. The shallow water and soil article is concerned ...
  • 4,349
1 vote

Natural nuclear explosions

All the evidences are that nuclear explosions could have happened in the mantle during the geological time. The best example being the Permian End Extinction. You can read my paper in: https://...

Only top scored, non community-wiki answers of a minimum length are eligible