dating tips for finding a date - Radiometric dating errors

Was Rb-87 or Sr-87 added to the rock by some unknown process?

Was one of them removed from the rock by some unknown process?

radiometric dating errors-62

The amount of Sr-87 that was already in the rock when it formed, for example, should be proportional to the amount of Sr-86 that is currently there.

Since the data are divided by the amount of Sr-86, the initial amount of Sr-87 is cancelled out in the analysis.

In this report, for example, we are told that using one radioactive dating technique, a lunar rock sample is 4,283 million years old, plus or minus 23 million years old.

In other words, there is a 95% certainty that the age is somewhere between 4,283 23 million years and 4,283 – 23 million years.

Sr-86 diffuses more quickly than Sr-87, and that has never been taken into account when isochrons are analyzed. Perhaps, but it’s rather tricky, because the rate of diffusion depends on the specific chemical and physical environment of each individual rock.

If the effects of diffusion can be taken into account, it will require an elaborate model that will most certainly require elaborate assumptions. Hayes suggests a couple of other approaches that might work, but its not clear how well. If you believe the earth is very old, then most likely, all of the radioactive dates based on isochrons are probably overestimates. I have no idea, and I don’t think anyone else does, either. Hayes’s model indicates it could add as much as 29 billion years to ages determined with rubidium and strontium, although his model is rather simplistic.

That’s just over half a percent error in something that is supposedly multiple billions of years old.

Of course, that error estimate is complete nonsense.

It refers to one specific source of error – the uncertainty in the measurement of the amounts of various atoms used in the analysis.

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