Chapter 3 - Relative-Age Dating

Unconformities are gaps in the rock record that may indicate periods of erosion or non-deposition.

Radiometric dating involves measuring the amount of radioactive decay in a rock layer to determine its age.

Index fossils are fossils of organisms that existed for a relatively short period of time and are found in many places.

Index fossils are fossils of organisms that were widespread but existed for only a short period of time. They are used to determine the relative age of rock layers by comparing the fossils found in different layers.

The principle of fossil correlation states that similar fossils found in different rock layers indicate that the layers are of similar age.

Relative age dating is a method used to determine the age of rocks and fossils in relation to one another, without determining their exact age.

Sedimentary layers provide a chronological record of geological events and can indicate the relative ages of the rocks.

The Law of Superposition states that in undisturbed sedimentary rock layers, the oldest layers are at the bottom and the youngest layers are at the top.

Fossils are the preserved remains or traces of ancient organisms, which can provide important information about the history of life on Earth.

Erosion can remove layers of rock, creating unconformities and making it difficult to determine the relative ages of the remaining layers.