A discussion of geologic time, along with a presentation of evidence for the time span involved.

Take a quick look at Earth's geologic time scale.

A discussion of geologic time, how scientists use the concept, and how they have determined its span.

This site provides information about the geologic relationships of rock layers, as well as much about geologic time and the history of Earth.

This illustrated timeline from the Lunar and Planetary Institute provides a journey through four-and-a-half billion years of time from the birth of our solar system to its current existence today.

A lengthy scholarly article that discusses the geologic time scale, its history of development, age-dating events that occurred in different eras, and how absolute and relative dating are used to assess the ages of the Earth and Moon....

Photos, illustrations, 3D graphs and animations are part of this investigation into the geology and landforms of the Grand Canyon. Learn detailed information on the formation of the canyon, the rock layers, and the prehistoric life that...

This is a good resource for anyone who wants to understand the historical development that led to our understanding of relative dating. This site also has links to index fossils and a table of geologic time.

The geology of Alberta is profiled on this site. Drop menus reveal sub-topics ..geological time scale, rock formations in Alberta, and so forth.Graphics and maps are included.

Explore geologic time of the Earth and learn how radioactive decay helps to establish a timeline.

An learning activity to help young scholars grasp the concept of relative dating and geologic time.

This is a good source for getting an in-depth description of using radioactive decay to measure the ages of rocks. In addition to describing the process of radiometric dating, this resource also includes a geologic time scale and four...

This in-depth article illustrates the concept of geologic time, and helps the learner understand why fossils are rare.

These time lapse movies of Kilauea are hosted by the Hawaiian Volcano Observatory. This resource also includes a webcam which provides near real time footage of two active volcanoes.

Understanding Evolution provides evidence for evolution using fossils. There are also links to lesson plans.

Use this interactive to explore key human impacts on the environment and how they have affected Earth's landscape, ocean, atmosphere, and biodiversity. The column on the left-hand side of the screen lists different human impacts on the...

Discover the fascinating world of the stingray by learning about its distribution, behaviors, habitats, geological time periods, and classification through videos, news, photos, descriptions, and external links.

An explanation of the Earth's atmosphere and how it has evolved over geologic time.

The Understanding Evolution site provides evidence for evolution in biogeography utilizing relative dating, geography, and plate tectonics.

This dinosaur site, containing eight different sections, includes topics such as: 101 crazy theories about dinosaur extinction, the pattern and timing of extinction, evidence for late cretaceous climatic change, gradual extinction and...

Many of the interesting landmarks around the world are formed over time by natural processes familiar to us in our everyday lives. This still collage produced for Teachers' Domain features images of a variety of beautiful natural wonders.

Instructional module focusing on the rock cycle. Discussion includes the concept of uniformitarianism and how earth materials change from one form to another. The site also includes an interactive practice quiz and links relating to the...

The breathable air we enjoy today originated from tiny organisms, although the details remain lost in geologic time. Scientific American helps uncover this mystery.

Describes plants and animals that lived during the Ordovician Period, where it falls in the geologic time scale, tectonic activity happening then, the climate and environment, and extinction events.