Thus, he already ‘knows’ that the igneous dyke must be younger than 200 million years and older than 30 million years.
(Creationists do not agree with these ages of millions of years because of the assumptions they are based on.) Because of his interest in the volcanic dyke, he collects a sample, being careful to select rock that looks fresh and unaltered.
These were then eroded and Sedimentary Rocks B were deposited.
25,000 BP to 16,000 BP) and subsequent domination by subarctic conifers.
Here he can see that some curved sedimentary rocks have been cut vertically by a sheet of volcanic rock called a dyke.
It is clear that the sedimentary rock was deposited and folded before the dyke was squeezed into place.
Unreliable specimens which were dated by conventional C decay counting, samples obtained from poorly preserved fossils, samples inconsistent with geological context, and samples dated by combining bone fragments of several species and whose exact provenances are unknown are rejected.
The timing of extinctions was compared with the vegetational changes.