With this in mind geologist have long known that the deeper a sedimentary rock layer is the older it is, but how old?
Although there might be some mineral differences due to the difference in source rock, most sedimentary rock deposited year after year look very similar to one another.
Then after another 5,000 years half of the remaining parent isotope will have decayed.
While people are most familiar with carbon dating, carbon dating is rarely applicable to fossils.
The most obvious feature of sedimentary rock is its layering.
This feature is produced by changes in deposition over time.
Scientists can use certain types of fossils referred to as index fossils to assist in relative dating via correlation.
Index fossils are fossils that are known to only occur within a very specific age range.With out individual time stamps the process of dating these structures could become extremely difficult.To deal with many of these problems geologists utilize two types of geologic time: relative time and absolute time.This uses radioactive minerals that occur in rocks and fossils almost like a geological clock.It’s often much easier to date volcanic rocks than the fossils themselves or the sedimentary rocks they are found in.The Wheeler Formation has been previously dated to approximately 507 million year old, so we know the trilobite is also about 507 million years old.