Fossil assemblage B includes the index fossils the orange ammonite and the blue ammonite, meaning that assemblage B must have been deposited during the interval of time indicated by the red box. Radioactive isotopes are unstable, so they are transformed into a more stable ones at a rate known to scientists emitting radiation. Pirolusita infiltrations in limestone. Paleomagnetism measures the ancient orientation of the Earth's magnetic field to help determine the age of rocks.
Provide an idea of the sequence in which events have occurred.