Relative dating geology methods
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.
So, often layers of volcanic rocks above and below the layers containing fossils can be dated to provide a date range for the fossil containing rocks.
The atoms in some chemical elements have different forms, called isotopes.
This chapter expands on the concepts focused on the solid earth (geology).
We begin with a discussion on geologic time and the rock cycle — a graphic and conceptual model to illustrate common rocks and earth materials and the processes that form or change them, over time.
Carbon-14, the radioactive isotope of carbon used in carbon dating has a half-life of 5730 years, so it decays too fast.
If a radioactive isotope is said to have a half-life of 5,000 years that means after 5,000 years exactly half of it will have decayed from the parent isotope into the daughter isotopes.
Geology is founded on basic principles that are useful for making many useful observations about the world around us.