Exercise 2 relative and absolute dating of geologic events answers
Correlation with them has helped geologists date many New Zealand rocks, including those containing dinosaurs.
Bring relative dating principles to life with the activity Rock layers and relative dating.
Relative dating does not provide actual numerical dates for the rocks.
Fossils are important for working out the relative ages of sedimentary rocks.
Relative dating is used to arrange geological events, and the rocks they leave behind, in a sequence.
The method of reading the order is called stratigraphy (layers of rock are called strata).
Different species of ammonites lived at different times within the Mesozoic, so identifying a fossil species can help narrow down when a rock was formed.
Many of these organisms have left their remains as fossils in sedimentary rocks.
Some fossils, called index fossils, are particularly useful in correlating rocks.
For a fossil to be a good index fossil, it needs to have lived during one specific time period, be easy to identify and have been abundant and found in many places. If you find ammonites in a rock in the South Island and also in a rock in the North Island, you can say that both rocks are Mesozoic.
Scientists are always spouting information about the ages of rocks and fossils. Well, they figure it out using two different methods: relative dating and numerical dating.
Let's find out more about these geological dating methods in order to understand how Paul the Paleontologist can be so sure about the age of his dinosaur fossils.