Absolute dating radiometric dating
Fossil Frustrations New Scientist Nov 1983 " Ager Derek I think of no cases of radioactive decay being used to date fossils.
" Ultimately fossils are dated using Darwinian evolutionary theory.
The age determined by relative dating is based on the rules of super imposition and the presumed age of strata based on fossils.
This is based on the concept that, in a normal depositionary sequence, the deepest layers are also the oldest.
absolute dating is based on calculations of the age of rock strata based on half lives of minerals, relative dating is based on the assumed age of fossils found in the strata and the laws of super imposition. The absolute dating is based on calculation of half life.
The law of superimposition that the oldest fossils are found on the bottom is superseded by the law of decent with modification that the simplest fossils are the oldest and the youngest fossils are the most complex.
This is the basis of relative dating Fossils Out of Sequence Palaios June 1990 page 227 "We define stratigraphic disorder as the departure from perfect chronological order of fossils in a stratigraphic sequence, in which an older fossils occurs above a younger one. stratigraphic disorder at some scale is probably a common feature of the fossil record.