As a result I was using some of my texts to examine the decay of Americium 241 and noted the naturally occurring decay chains for U235, U238 and Th232, as well as the fully decayed chain for Pu241.
Geologists, paleontologists and anthropologists use these techniques to establish the age of fossils.
By learning how relative and radiometric dating methods work, you can better understand how science uncovers the history of our world.
Link between radiometric dating and lightspeed Oklo What about the RATE group?
Isn’t dendrochronology accurate for checking radiocarbon dating?
-- some quotes on radiocarbon dating Change in Decay Rates Atomic Ages Cesium 133 Oldest Living Tree?
Setterfield: Atomic decay rates do not depend on the speed of light.
Both are, however, 'children' of the same parent -- the Zero Point Energy.
Because of this, and because the speed of light is in the numerator of every reduced radio decay rate equation, any changes in the speed of light are indicating changes in atomic decay rates. Importantly, the original short half-life elements were also a contributor and they have gone now.
This also made for rapid heating of the earth interior (cool to start with).