Dating method determined numerical age earth
Each layer at this outcrop contains different types of fossils.
The eras are broken down into periods, which represent smaller units of time.
In addition, not all rocks contain suitable minerals for absolute age dating, especially sedimentary rocks.
However, we do have ages for some sedimentary rocks due to the presence of bentonites, or ancient volcanic ash horizons, that do contain minerals that can be used for absolute age dating.
The half-life of C is only 5,730 years, meaning it is only useful on sediments younger than about 50,000 years.
Combining absolute age with relative age of rock formations can lead to really strong data to interpret!