Geological Time Scale

The geological time scale is a system of chronological dating that relates geological strata to time. It is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships between events that have occurred during the Earth's history.

Eras of the Geological Time Scale

The geological time scale is divided into several eras, each of which is further divided into periods and epochs. The major divisions of the geological time scale are:

• Precambrian Eon
• Paleozoic Era
• Mesozoic Era
• Cenozoic Era

Key Concepts

There are several key concepts to understand when studying the geological time scale:

• Relative Dating: This is the process of determining the relative order of past events without determining their absolute age. It is based on the law of superposition, which states that in any undisturbed sequence of rock layers, the youngest layer is on top and the oldest is on the bottom.
• Absolute Dating: This is the process of determining an age on a specified chronology in archaeology and geology.
• Index Fossils: These are fossils of organisms that lived for a relatively short period of time and are used by geologists to correlate the age of rock layers.

Study Tips

When studying the geological time scale, consider the following tips:

• Memorize the major divisions of the time scale, including the eras and their respective periods and epochs.
• Understand the principles of relative and absolute dating, and how they are used to determine the age of rock layers and fossils.
• Be familiar with index fossils and their significance in correlating the ages of rock layers.
• Practice using the geological time scale to interpret the timing and relationships between geological and biological events throughout Earth's history.

With a solid understanding of the geological time scale, you will be better equipped to interpret the Earth's history and the changes that have occurred over millions of years.

[Geological Time Scale] Related Worksheets and Study Guides:

• Geologic timeScience • Eighth Grade