What are preserved remains or traces of living things called?

What is the term for preserved remains of animal activity?

What describes the weather conditions in an area over a long period of time?

What is the principle that states younger rocks lie above older rocks in layers that have not been disturbed?

What is the term for a break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time?

What is the ordered arrangement of rock layers based on the relative ages of the rocks?

What is any method of measuring an object in years called?

What is the time it takes for half of a radioactive isotope to decay called?

What is the process in which a radioactive isotope breaks down into a stable isotope of the same element or another element?

What compares the relative percentages of a parent isotope and a daughter isotope?