Age dating rocks

25 Apr

Simply stated, each bed in a sequence of sedimentary rocks (or layered volcanic rocks) is younger than the bed below it and older than the bed above it.This law follows two basic assumptions: (1) the beds were originally deposited near horizontal, and (2) the beds were not overturned after their deposition. Students not only want to know how old a fossil is, but they want to know how that age was determined.Some very straightforward principles are used to determine the age of fossils.Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed.The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay.Far from being data, these dates are actually interpretations of the data.As discussed before, the assumptions influence the interpretation of the data.

3) To have students see that individual runs of statistical processes are less predictable than the average of many runs (or that runs with relatively small numbers involved are less dependable than runs with many numbers).

Geologists generally know the age of a rock by determining the age of the group of rocks, or formation, that it is found in.

The age of formations is marked on a geologic calendar known as the geologic time scale.

Absolute dating places events or rocks at a specific time.

If a geologist claims to be younger than his or her co-worker, that is a relative age.