Relative dating of fossils is based on what dating for widow
This is because new sediments are always laid down on top of sediments that have already been deposited.
So, when looking at the history of a cliff face, it is important to read the story it tells from the bottom layer up.
The second method is called absolute dating and is done by analysing the amount of radioactive decay in the minerals of the rocks.
Scientists find out the age of a dinosaur fossil by dating not only the rocks in which it lies, but those below and above it.
Due to the believed irreversibility of evolution, scientists believe that "fossils offer an unambiguous timescale for relative age determinations." page 395 Schindewolf Comments on Stratigraphic Terms American Journal of Science June 1957 The geological column which has been constructed on the theory of evolution is used to establish relative dating of the strata in which the fossils are found.
The Geological column is then used to support the theory of descent with modification on which it is based.
The fossils in the strata are used to determine relative dates, the simpler the fossil the older the fossil.
As radioactive dating can not be used to date sedimentary rocks only igneous rocks, absolute dating of fossil bearing sedimentary rocks is impossible.
Ammonites, shelled relatives of today’s octopus, make ideal index fossils.
Suppose a dinosaur fossil has been found in the beds of an ancient delta (the mouth of a river leading to the sea).
[SE] The principle of cross-cutting relationships states that any geological feature that cuts across, or disrupts another feature must be younger than the feature that is disrupted.
An example of this is given in Figure 8.7, which shows three different sedimentary layers.
The lower sandstone layer is disrupted by two faults, so we can infer that the faults are younger than that layer.