Geological Time Vocabulary

a scientist who studies Earth's crust as well as the processes and history that shaped it

• Biologist

• Geologist

• Paleontologist

• Meteorologist

a scientist that studies fossil remains found on Earth's surface in order to study primitive life forms

• Biologist

• Geologist

• Paleontologist

• Meteorologist

layers of sedimentary rock

• Relative Age

• Strata

• Law of Superposition

• Fossil

states that younger layers of rock are deposited on top of older layers

• Law of Crosscutting

• Relative Age

• Absolute Age

• Law of Superposition

determines the order of past events but not the absolute age

• Relative Age

• Index Fossil

• Law of Superposition

• Half-Life

preserved remains or traces of animals, plants, and other organisms from the past

• Half-life

• Radioactive Decay

• Index Fossil

• Fossil

a fossil that is easily recognizable, abundant, has wide geographic distribution, and lived a short time that is used to determine the age of rocks and other fossils.

• Radioactive Dating

• Relative Age

• Index Fossil

• Absolute Age

length of time required for half of the radioactive atoms in a sample to decay

• Radioactive Decay

• Radioactive Dating

• Absolute Dating

• Half-Life

Uses the decay of radioactive elements to give the age of a rock as the number of years since the rock formed.

• Relative Age

• Absolute Age

• Half-Life

• Radioactive Dating

uses the decay of radioactive elements to find the absolute age of a rock or fossil

• Radioactive Dating

• Half-life

• Index Fossil

• Law of Superposition