Clot
clots
land
lands
lots
slot
loan
loans
slant
sand
coal
coals
An important tool in understanding the actual numerical dates of past geologic events is radioactivity.
1. Fracking
2. Air pollutants.
3. Decomposition of organic matter e.g. in landfills.
4. <span>Chlorofluorocarbons </span>mainly in refrigerants and air conditioners.